Mike's journal

Dinghy Project 2

You can never have (or build) too many small boats :-). 
Here is the planning for this project, including a summary of various
nesting and folding dinghies that I found.
 
I decided on building the Spindrift Dinghy 10N.   
 

Start of construction

Spring Hill, 17 Jan 2012 So I guess this is the actual start of construction.  Woo-hoo!

I received 3' of ⅛" x 1½" T-316/316L stainless steel today and brought it over to the fabricator.  This is for the plate at the base of the mast and the connectors for joining the two halves.  Garry Prater's plan called for 2 connectors, but I think I'll add a 3rd in the middle as I've shown here.  For the two bolts on the left of this plate (that will overlap the trunk, shown in blue), I'll use the West System technique of drilling the holes oversize, filling them with epoxy, and embedding the bolt's threads into that epoxy plug.  I believe the West System guys have determined this produces a very strong connection*.

Spring Hill, 26 Jan 2012 And the results back from the fabricator.  Hey, it's a start. Now I need to get back to Man-O-War to start on the hull.

Man-O-War, 24 Feb 2012 The plywood and resin arrive at Man-O-War.   Less than half of the shrink-wrap put on by Abaco Shipping (Heavy Lift Services) survived the passage :-(.  I should have done it myself.  Thankfully, everything in the shipment arrived.   The packaging and shrink-wrap of the plywood by World Panel Products was superb (really a 1st class outfit) and came through fine.		Being on an island, everything has to be brought in by boat. Here is the regular cargo barge from Marsh Harbour.
Man-O-War, 25 Feb 2012 I was fretting over having to construct a table for this.  But the skid that the plywood was shipped on ought to work.  Here it is laid on top of some cinder blocks.  Then the stack of plywood on top of it.   I'm in about the same spot I was before, next to the water.  Kewl.

Man-O-War, 26 Feb 2012 In researching this project, I came across a couple postings suggesting that a small increase to the freeboard might be a good idea*.  In particular, the post at the bottom of this thread seems both thoughtful and well written.  I quote from it: Note: I am adding 2 inches to the freeboard to the design. I did this on the fiberglass one I made, as did several others who built them in Panama. Most owners I know say they wish they had more freeboard...but the owners I know use them as dinghies for their larger boats, and often have to haul groceries and two adults around.... Might not be needed if you use it only for a fun boat, as getting splashed is part of the fun. If waters are choppy in your area, though, it is a modification worth considering. Be sure to think through how to do this! Simplest method to avoid mistakes is to draw the plans out full size, then continue the lines up: thus, extending the existing stem lines and the transom corners up along the existing lines. You will end up with a boat slightly longer and wider, but having the exact same shape as the original but just more freeboard. The author is somebody I'd like to buy a beer someday.  BTW, he has an interesting description of building a stitch & glue (Spindrift) dinghy using fiberglass only, when you don't have access to proper plywood.    Sidetrack asking in the B&B Forum ... There are no Spindrifts nearby that I know of, so I figured I'd ask in the B&B forum.  Except for Graham's reply (where I simply stopped monitoring the thread) I was really surprised by the level of vitriol, pomposity and rigidity in the response.  Maybe the election season is taking it's toll on reason?  Or I'm simply too sensitive. [28 Feb 2012] I wonder about the dynamics here.  Are there people on the forum with a different or more reasoned point of view but unwilling to express it, for fear of being ridiculed and ostracised?  I imagine it's the sort of social system that has been studied to death by psychologists, sociologists and industrial engineers.  Not the same as a Facebook or Twitter.  More like what happens in a company "too long in the tooth".  Where things get moldy, dogmatic, regimented, inbred, bureaucratic.  I certainly saw a bunch of it on the job.  There is a memorable scene from the movie, Brazil, where the protagonist needs to access a computer and the owner of the terminal does all he can to keep control.  It's 9:00 into this clip (just click on the Play button)---> Or on Youtube at higher resolution. The antithesis of course, is a vibrant, energetic, innovative community (in this case, I'm thinking the Panama cruisers).  Hmm. So, my desired use: Cruising, at times hauling lots of stuff/persons, potentially in sloppy conditions.  I think these are the tradeoffs in adding a bit to the freeboard: Pluses Minuses A slightly drier ride More carrying capacity Maybe a little better feeling of security The oarlock will be 2" higher over the water so less likely to catch on the backstroke More windage - roughly 15% more surface area Just slightly more weight More height stored on deck - say, 2 inches, but maybe less if the centerboard trunk rests on the hatch and that determines the height stored on deck - TBD The transom might have to be notched to lower the outboard - [7 Mar 2012] So, with the additional 2", the height of the transom becomes 17".  That looks like a good fit with my outboard which is 17" from the mounting bracket to the fin located above the prop. It looks like there is room to spare on the plywood.  I plan to add 2".  No progress today, as a front passes.

Man-O-War, 2 Mar 2012 The first step is to join 8' and 4' plywood panels to make two 12' x 4' panels from which to cut the 10'-long bottom and side sections.  The plans recommend either a butt or scarf joint.  A scarf joint just seems more proper.  I started out with an 8:1 ratio for the scarf (shown here) but switched to 12:1 for a 3" overlap.  12:1 seemed better on ¼" plywood.   Using the router worked pretty well - it just took a while.  I experienced some tear-out where the edge tapered down
to .. well, nothing, but found I could avoid that by leaving a slight (say 1/16" x 1/16") scrap portion of the wood remaining, then removing that with a sanding block.  The edge then ended up paper thin, FWIW.   I used the other panels for my straight-edge guides.  This worked pretty well because I could line up the long edges of the panel I was cutting with the top and bottom guide panels.    I don't know that this is the best procedure, but here is what I did ... routed the edge down to the 12:1 ratio sanded it with 80-grit sandpaper on a sanding block to smooth down any rough spots and take off the ⅛" x ⅛" scrap from the edge wiped it down with a wet cloth to clean off the sawdust and open up the pores the next day brushed it off to remove any remaining sawdust exposed the wood to the sun for a couple hours to open the pores and try to get it as dry as possible - at the same time exposing the cans of resin and catalyst (West System 105 & 206) to the sun to warm them up a bit to make them a little less viscous pre-coated the wood of the joint with a generous amount of epoxy let that set for about an hour (unjoined) brushing it occassionally as the wood continued to (slightly) out-gas while it was still tacky, coated it with epoxy slightly thickened with colloidal silica to take up any voids and help the resin stay in place tacked the joined panels in place using finishing nails to keep them from sliding apart - using wax paper between the layups.  Then a nice flat 3x6 over the joints and a couple cinder blocks on top of that.  Ie. table top, wax paper, 1st layup, wax paper, 2nd layup, wax paper, 3x6, cinder blocks let it set for 24 hours drove the finishing nails through into the table this suggests "allow[ing it] to cure for 5 to 7 days before removing clamps".  I allowed a couple days before bending it, but mainly because the weather was bad and I couldn't work on it.  And this suggests "plac[ing] the leading exterior edge of the scarf toward the stern" which (if I'm reading that right) I did.

Man-O-War, 10 Mar 2012 I've cut out the bottom, side (wings), bulkhead, and transom pieces.  Then attached the wings to the bottom pieces and wired the bottom pieces together along the center line per the plans.  Now the thing sort of unfolds like an origami.   I think we tried to finesse it a bit (inserting the blocks, etc).  All that really needs to be done is support the ends of the wings to avoid stressing the fiberglass tape.  In hindsight, unfolding it is much easier that we made it look here.
Here is the initial result.  I need to go through and adjust the seams to get a better fit.
Man-O-War, 16 Mar 2012 Lots of wind and intermittent rain the last couple days so progress has been slow.  Anyway, I'd suggest when attaching the wings to the bottom and transom, first loosely wire them in a couple spots along the edge just to keep them from flopping around.  Early on, secure the transom and two or three wires on the aft ends of the wings because they determine where the bottom edge of the wings will rest on the surfaces of the bottom pieces at the aft end.  That overlap starts at 0 at the front end (where the butterfly glass tape is) to a fair amount at the transom.  And affects where you drill your holes as you go from the nesting bulkhead to the transom.   The fit of the forward bulkhead has been very difficult, with the chine not pulling in very easily.  I've checked and rechecked and don't see where I messed up on the measurement.  Hmm.  I ended up cutting a new forward bulkhead with the width across the spot where the chine is located ½" wider on each side.
The fiberglass tape where the wing attaches to the bottom has a lot of stress on it.  It started to break at the aft end where probably the most stress is located.  I simply added another wire tie there (using 12 ga. copper wire, where
the rest of my ties are 14 ga.) and that appears to have prevented further breakage.

Man-O-War, 24 Mar 2012 Here I'm attaching the gunwales, breast hook and knees.  A couple things to note:
	1.	To check for racking, I've run fishing line from the point above where the forward bulkhead is located (where the lines were drawn from the plans) back to the opposite corners of the transom (where the knees are).  There was about ¼" gap between the two lines where they cross.  I pulled the two opposite corners of the hull down a little with light (⅛" nylon) line to
		take that out while the epoxy sets.  I also checked the distance between those points.  They differ by about 1/16" after pulling down the corners.
	2.	You can see in the photo a white line coming out just below the foremost clamp and running around the bow where it then reenters the hull, forming a single tight loop and having the effect of pulling the sides together and reducing the angle at the bow.  I adjusted the line until I got the same angle produced when the gunwales are installed.  I installed the breast hook (using thickend epozy and 1" #6 screws) before installing the gunwales as the plans recommend.  This line holding the bow to the final angle then made that much easier.  The gunwales on the aft end didn't change the angle between the sides and transom much so fitting and installing the knees was pretty easy.  There, I installed the gunwales first, then the knees.
	3.	You definitely want to use some screws (I used 1" #6 bronze FH screws) to hold the gunwale strips in place as you work your way aft, gluing and clamping the strips in place.  The strips will be slipping around quite a bit otherwise.

Here are the clamps I made from some ½" plywood left over from the previous dinghy project.  The legs are 2" x 4" with two 1" x 1" spacers at the top.  I drove a small finishing nail through the legs and the spacers to keep everything together (important when in use, as the epoxy is on a countdown to setting).  The screw is a stainless steel deck screw with a square hole - handy for catching the screw driver in when you're juggling 3 or 4 things with just 2 hands.  I wrapped the legs in tape (I had some 2" clear packing tape) to keep the clamps from getting glued to the hull or gunwale.  These clamps worked out pretty well, I think.  They weren't *too* hard to make up - lay out all the pieces in a grid on the plywood.  Then it's easy to cut them out with a coarse blade and if using a jig saw, the option that tilts the blade to make it pull through the wood.  Ie. the plywood edges don't have to be pretty.  Make sure you have enough clamps.  I had 22 on each side and that was probably enough (though you can never have too many).

Man-O-War, 28 Mar 2012 There were a couple problems that showed up looking down the center line with the hull turned upside down.  First, there was about ¼" droop midway between the forward bulkhead and the nesting bulkheads - again, this is looking at it from the bottom.  This was easily removed by shaving a little of the gap in the seam forward of that.  I gradually tapered the amount removed up to where the fiberglass tape is located.  I first removed 4 or so of the ties in that area.  Then it was very easy to shave down the gap - effectively lowering the stem slightly (looking at the hull upside down) relative		Not a very good photo, but the idea is to stick the Japanese pull saw in the seam and carefully rasp it down a little at a time, checking the centerline for a nice smooth line as you go.
to the droop.  I used a small Japanese pull saw but any fine-tooth saw should do.  The pull saw is nice though because you can twist it a bit in the gap as you draw on it and in that way remove just the slightest amount of wood - in sort of a rasping motion.  I then reinstalled the ties.  The forward bulkhead had to be shortened slightly - the wood easily removed using sandpaper on a sanding block.  I'm using 40-grit sandpaper for these coarse modifications.  This Okoumé plywood is a joy to work with - uniform, easily shaped, takes epoxy resin like a bandit.  It sort of reminds me of Divinycell foam.   Second, there was a slight droop in the center line (again, looking at the hull upside down) a little before the transom.  It was maybe ⅛".  Same procedure - I removed 3 or 4 ties just before the transom and shaved down the gap until pulling it in caused the droop to go away.  Then I reinstalled the ties.  I suspect this sort of minor adjustments is standard procedure with stitch & glue construction.   I also rechecked for any racking.  There is absolutely none now.

Man-O-War, 2 Apr 2012 My back is killing me.  But I've managed to tape the inside seams.   Just one thing to note.. I had thought I would make the 1" fillet in the seams and tape them in one step.  I planned to let that set up and then remove the wires.  But my wire ties stood up too high for a 1" diameter fillet.  I suppose I could have flattened the wire loop inside the hull when I inserted them, but that could have made it a bear to pull them out after the epoxy had set.  It could also be because I used 14 ga. (12 ga. in difficult spots) copper wire.  16 ga. monel may have worked better.   Instead, I took the alternative path of making low "tack weld" fillets between the wire ties (the plastic West System mixing stick is ¾" diameter), letting that set, removing the wires, sanding the ¾" fillet to make sure there was a good bite, then going back and putting in the 1" dia. fillet and tape over it.    For the outside seams, I only taped over the centerline and around the transom.  Not the chine seams.  I figured they have good support in compression, with the sides resting on the bottom pieces.  And for tension, there will be two layers of 6 oz. cloth for support (ie. one layer inside and one outside), along with the inside tape.   Now I'm going to deviate from the plans a couple ways.  First, I'd like to shape the aft seats to form-fit the bow when nested.  Second, I'd like to sheath both the interior and exterior with a layer of fiberglass cloth.  That's because I'd like to not worry as much about breaking the hull's surface (that is, the paint and sealing coat of epoxy resin) when pulling it up onto a knarly beach or dropping something into the dinghy from the dock, say.  I have some 6 oz. cloth for the floor and bottom, and 4 oz. cloth for the vertical surfaces.  So, my plan is to apply a layer of 6 oz. cloth inside and then -OMG- cut it in half.  Then I'll be able to measure for the aft seats.  An added benefit will be being able to fit the daggerboard trunk with the forward half hull in a more accessible position.  BTW, the plans stress waiting until the interior is installed *before* cutting it in half.  I'm thinking the layer of glass cloth will stablize any movement in the shape.  And I'll clamp the two halves together and check for racking, etc. before gluing in those remaining interior pieces.  There may be a benefit over the original plans because the faces of the nesting bulkhead will be finished off and thus their angle meeting the daggerboard trunk will be in it's final form.  With regard to sheathing everything in fiberglass cloth, I figure that will add roughly 5 pounds to the overall weight - an acceptable tradeoff IMO.

Man-O-War, 11 Apr 2012 I measured the cloth for the inside and outside by draping it over the outside, twice.  The cloth is 60" wide which fits perfectly between the nesting bulkhead and transom.  So, I ran the length of the cloth from gunwale to gunwale - about a 6' length of the cloth.   And just to repeat, the plans do not call for fiberglass cloth here - just a coat of  resin ... In a phone conversation with the designer, I asked him about using cloth here and he emphatically said, "No, *NO FIBERGLASS CLOTH*".  But, the plans also warn you that once you put the dinghy in service, you should occasionally check the surface for cracks which would then let water start to get into the plywood.  I built a 16' redwood "stripper" canoe when I was a kid and used a layer of cloth inside and a layer of cloth outside, and I can tell you that that surface was nearly indestructible.  I've read somewhere (many years ago) that fiberglass cloth+resin have a very strong systemic benefit - I think the analogy they used was concrete and rebar.  Also, I believe cloth helps you apply a consistent amount of resin.  And one which, if you are careful to squeegie out the excess resin, can be fairly economical on the weight.  Anyway, I chose to use cloth - rebel that I am :-).

Here are the results after glassing the inside.  Note the doublers for the connectors on the floor next to the nesting bulkhead.  I also rechecked for racking - still none.   The West System 6 oz. cloth is very nice to work with - it wets out easily and bends around odd angles pretty well.  It's a little more expensive, but worth it IMO.  This is the first time I've used West System's cloth (as opposed to the cheapest I could find) and don't know why I was so stingy with the cost of cloth in the past - kind of dumb.  It's like the plywood - if you're going to put a couple hundred hours into a project, you ought to go with the best materials.

Man-O-War, 12 Apr 2012 The cut ...		and the fit.
The fit is quite good now.  But this is before installing the keel which will push the bow half up a little - making the fit a little looser.  Still, it shouldn't be bad.  And as I said above, I plan to make the bow fit between the aft seats fairly snug. [26 Apr 2012] With the keel installed, there is a ¼" gap between the bow stem and the inside of the transom when nested.  Seems good to me.

Man-O-War, 2 Apr 2012 I am planing to use the connector design suggested by Garry Prater.   I sent Garry a note asking if, based on his experience, he would recommend any combination of A, B, or C bevels that I'm showing in this diagram from his plan.   He replied that he didn't recommend C.  He had tried it on his and it didn't really help but did make the "pointy" end of the bevel fragile.  Regarding B, he said, "The B bevel would work as long as it's a square cut (perpendicular to the plywood surface).  Making it parallel to the side works well.  It would serve to help guide		From: http://www.pbase.com/onceagain/connector_design
the bow section into the center although I never really had a problem with it."  He also suggested rounding the inside corner for B (to avoid stress there), which I've added to the diagram here.  Thanks Garry. [8 Apr 2012] Since then, I've modified the A Bevel a bit to make it clearer and added D.  I think A now appears to be more of a "guiding bevel" than a "locking bevel" when engaged, with less stress on the pointy edge.  And possibly viable.  D probably has the same weaknesses as C.

Man-O-War, 14 Apr 2012 Here are the two simple jigs I made for routing the connectors.
This is for the hooks. The horizontal stick, just above the clamps, is removed to make the long routes (on the aft half).		This is for the plates. The first route (for the hook) has been made.		And some of the results. I need to round over the edges yet.

I applied a layer of 6 oz cloth to the outside and both sides of the transom.  And then installed the keel and cut out the plywood for the seats.  I'm taking a short break now to go sailing.  I'll be joining Edmund on Panope from Barcelona to Corsica.  Here is my trip report.  Please check back here in July when I will continue this project.
 

Well, I'm back from the trip and slowly getting back to projects.  First up - the seats for the aft section.
I laminated a couple pieces of 1/16" (3mm) Okoumé plywood to make up each of the sides of the aft seats.  First, I figured out the shape of the top by cutting and fitting cardboard around the bow section as I lowered it into the stern half.  From the cardboard, I made a couple plywood forms for each side - the darker crescent-shaped plywood pieces in the photo above.  Then I laminated two pieces of the 1/16" plywood bent over the forms to make a ⅛" panel (shown here).  I also laminated three ¾" wide strips of ¼" plywood to make ¾" x ¾" rails where the side meets the top.  You can see the end of the rail sticking out in the bottom left corner.  I cut the ¾" strips "across the grain" to make them easier to bend.  They are temporarily screwed into the ends of the plywood form while the epoxy sets.		Here, the sides and top are fit together and we are looking down at one of the joints where the rails meet.  The blurry-looking spot is the top of the post which will be epoxied into the corner, upon which this joint then rests.  The rail on the left is the one that was epoxied to the laminate (see photo to the left).  I then notched that out to fit the three strips from the rail joining it here.  This is before gluing everything with epoxy.

I should have taken a photo of the glue-up.  But it wasn't anything special.. I found a nice, absolutely flat 2x10 plank.  I laid the seat's tops on that (upside down).  Then a couple cinder blocks to hold the plywood flat.  Then I put a liberal amount of epoxy on the pieces that would become the rails and posts, as well as pre-coating the plywood where the rails would lie.  I used thickened epoxy in the space where the posts meet the corners and a little where the curved rail meets the top (to take up any gap that might be there).  I put everything together, checking that the sides were square to the top and used a few small sticks, sheetrock screws and clamps as necessary to hold everything together until the epoxy set.  I then let it set up overnight.

After the epoxy set, I put fillets on all the inside joints.  I plan to cover the inside with a layer of 4oz. fiberglass cloth, so I beveled the edges of the rails and posts to make it easier for the cloth to bend around them.  I did that before gluing everything together, BTW.  I need to sand everything smooth yet.    (Try clicking on the image for a better view)

Now roughly fit in place.  I've rounded over the corners with a ½" radius router bit - a milestone that I've been looking forward to a long, long time :-).   I'll leave those lower plywood form pieces in place (they're attached with sheetrock screws from the inside) until just before I epoxy the seats to the hull.

A small thing, but here are the seat supports (a.k.a. deadmen).

I laminated them from ¼" x ¾" Spanish Cedar strips I had left over from the strip plank dinghy.   I used thickened epoxy to take up any gap between the hull and the first strip next to it.   The clamps are simple but can apply as much pressure as you need.  For more pressure, use a stiffer stick or a wider piece where it presses against the laminates.  That little piece at the bottom should be placed on edge like this so the force isn't applied "cock-eyed".   I'll bevel that inner, exposed edge to a 45° angle after the epoxy sets.

I checked the hull for racking just before gluing in the seats.  Here, the fishing line was about ⅛" apart where it crossed in the middle.  If there had been a lot of racking, I planned to pull down the high corners of the aft hull before gluing in the seats.  I decided that ⅛" was not enough to worry about.   BTW, I noticed that the heat from the sun created quite a bit of stress in the plywood of the unglued seats - causing them to distort.  The proper fit was early in the day, which was when I epoxied them into place.   Doing this project indoors would have been better.  Or at least, under a tarp.  The photos of the old MOW boatbuilders show them doing their small boats usually under a lean-to or the shade of a tree.  The big boats are usually out in the open.  I'm on the same spot shown about half way down on that page - where the captions say "William H. Albury Boat Yard, late 1940’s" and "A boat under construction at W.H.Albury Boat Yard, 1960’s".

For the thwart, I liked what Seaweed did and pretty much copied that.  Where I deviated: I opted for a narrow top over the daggerboard trunk.  I plan to mount the sail controls on a block epoxied onto the side of the daggerboard trunk and think that will work better with this arrangement.  And, I extended the ends of the seat to attach to the hull, making the support a little more straightforward IMO.

The seat is laminated from two layers of ¼" Okoumé plywood.  It is 9" wide.  The support rail under the front edge is laminated from three pieces of 1½" x ¼" Okoumé	This is still rough yet.  I'll trim the edge of the top over the dagger- board trunk so that it is flush with the support rails later.	I'll bond the seat top (both the top and bottom surfaces) and support rail to the hull with thickened epoxy fillets when I install it.
plywood.  This makes the seats appear to be 2" thick - a look that I liked in my previous dinghy.  The top and bottom edges are rounded with a ½" quarter round router bit so relatively painless when bumped.

Aft edge of the seat, looking at it from the bottom.   I'll add a little backing on what will be the top of the seat here as that sharp edge looks a little fragile.	And the forward edge of the seat looking at the support rail from the end, again from the bottom.   The little rolled edge, on what will be the bottom inside, is just an extra finger hold when lifting the bow section from here.
This is looking at the bottom of the seat where the support rails will butt up against the daggerboard trunk.   I covered the bottom of the seat with a layer of 4oz. fiberglass cloth before attaching the support rails.	Again looking at the bottom of the seat, now with the daggerboard trunk in place.
OK, I got a little carried away here.  This is the top of the daggerboard trunk where it butts up against the nesting bulkhead.   I was initially planning to use just one sheet of ¼" plywood for the seat top so I beefed up this area where it rests on the trunk.  Then I decided to use ½" for the top.  This extra support is now clearly unneccesary, but well.. there it is.  It weighs practically nothing so no harm IMO.	The aft end of the seat extends about 1⅜" from the end of the bow section, so about ⅝" space to hook over the ½"-thick top of the stern section's nesting bulkhead.
I'll screw this edge together as well.  Stainless steel screws on say, 6" centers.   This overhanging lip is the main reason I switched from ¼" to ½" for the seat.  ¼" didn't seem like enough to support this edge - especially with the weight of my rump resting on it.  ½" also seemed better for the narrow cover over the daggerboard trunk.   BTW, the background in this photo is the bottom of a Hinkley currently hauled out here at the boat yard.  Makes a nice backdrop :-).

Bow seat Man-O-War, 22 Aug 2012 Nothing much to report for the bow seat.  I used clamps and sticks to hold things in place until the epoxy sets (shown here).  Thickened epoxy to take up any gaps and for filets on all the edge joints.  I need to sand them, put a couple coats of epoxy resin on the new pieces, cut out the hole for the access plate and glue on the top.  I'm kind of obsessing over the oar storage and location of the access plate though.  Here I'm showing one (of many) cardboard models of the forward storage holder.   Kind of a cool squall moved over us quickly yesterday a little before sunset.  There was some lightning flashes in it but I didn't manage to capture any :-(.  The new wide-angle lens is nice for this big sky stuff.   Tropical Storm Isaac is threatening to visit us early next week :-).

Canon T2i, Canon 10-22mm @10mm f/5.6, 1/80 sec, ISO 100

Oars Man-O-War, 25 Aug 2012 I like Seaweed's design for storing the oars.  Here is my mockup ----> In it, I'm showing the same blade pattern as my last set of oars (apparently a fairly old design).   But, the oar blade simply screams to be spoon shaped.  Here is a spoon oar design by John DeLapp that looks nice.  I have some ⅛" (3mm) Okoumé I could use to laminate the blade (and then maybe be able to refine that top spline a bit).   Builders (e.g. here, here, here) note that their blades have a true spoon shape (that is, concave in two dimensions).  These racing oars:

do appear to have a slight cup in them.  I wonder what it would take to create a true spoon shape if I laminated the blade.  Lots of pressure bearing down in the middle of the blade with an elongated ring-shaped form underneath, I guess.  My main concern would be not starving the lamination of epoxy.  Hmm.

Here is a mockup using the spoon blade from John DeLapp's article:
I've marked where the leather would be located on the upper shaft (click on image to enlarge).   To maximize the oar's length, I was thinking I could use a sliding piece of PVC or aluminum pipe, stored on the lower shaft.  It would be about 20" long.  The overall length of the oar would be 6'10".	Having the blade point aft and partially under the seat probably looks a little better (compared with the first pair of photos above).   I'll need to notch a little out of the seat support.  The wider blade doesn't quite fit otherwise.

 
There was a small bump in the road when I got to installing the connectors.  The good news is that the gap between the bulkheads when nested is small - about ¼".  The bad news is, well.. 

The gap between the nesting bulkheads is about ¼" on the sides

BTW, they are snug in the middle

The Perko clamp is a little less than an inch "thick"

So it doesn't fit in the available space :-(

BTW, the space between the stem and transom is about ¼".  The bow section's keel is resting on the floor of the stern section.

And the space between the hull and aft seats is pretty snug.  The hulls slide together very nicely now.

So, there isn't enough space between the bulkheads for the clamp when the hulls are nested.  I think some of the options are:

• Slide the bow section forward about ¾" to create the needed space.  That would push the bow up against the transom if the aft seats weren't already in place, and cause the bow's keel to no longer rest on the floor of the stern section (putting the weight on the aft seats and transom).  In my case, I already have the aft seats nicely fitting around the bow's hull.
• Flip-flop the cutout piece so that the clamp would be located on the inside of the bow section.  The cutout piece would then click into place as the two halves slid together.  The main problem, I think, is that the overhanging lip on the thwart would be a tight fit over the, now offset, stern bulkhead as they slid together.
  [todo: add a little diagram of that here]
• Use something thinner (or use bolts) to join the bulkheads together.  Garry's plans show a door hinge as an alternative to the Perko clamps.  This doesn't seem nearly as convenient for assembling the dinghy in the water.  As Garry describes it, to assemble in the water, you sit in the stern section.  The bow section is floating quite a bit higher than the stern section.  You go to one side, push down the bow section on that side, latch that side's clamp, then do the same thing on the other side.  The door hinge wouldn't work here because it would need to be lined up to run the pin through it.  And trying to line up a bolt between the two bobbing halves seems challenging.

The solution I'm taking is to notch a small hole in the forward bulkhead that will "house" the clamp when nested.

The spot where the hole would be located is the small crescent-shaped piece of cardboard shown here.  The big chunk of cardboard above it is a mockup of the piece cut out of the stern section's bulkhead plus a protective housing over the top part of the clamp.	Here is a cardboard mockup of a protective housing for the lower clamp.  This was before I trimmed down the cardboard (to the lines).	Here the top and bottom clamps, with their protective covers, are shown clamped together.  The top one will be shaped down a bit in the final result.
I've also added a little ½" x ½" lip around the upper "protective cover".  The lip catches on the stern's bulkhead when the halves are joined.  You might need to click on the images to see what I'm talking about.  It should be easier to see in the finished results.   The cardboard is nice because it's ¼" thick so transfering the shape to the plywood should be straightforward - just trace out each layer of the cardboard onto plywood, cut, and finish.

Not much progress the past month or so.  The heat really slowed me down.  Then Sandy visited.  But I managed to glue the thwart in place, cover the fore and aft seats with 4 oz. cloth, and make up the protective housings for the clamps.  The housings are the light-colored plywood in these photos (click on image to enlarge):

Here the halves are joined and the clasp is closed.  We are looking at the bulkheads from inside the aft half of the dinghy.

Here the halves are nested.  We are looking at the outside of the bulkheads.

Here the halves are nested.  Now, we are looking at the bulkheads from the inside.  Note the opening cut into the forward bulkhead to "house" the bottom clasp.

I've decided to implement the protective housings in aluminum, instead of plywood.  The main reason is to reduce the amount of wood that I have to cut out of the forward bulkhead (photo above on the right).  Hopefully that will make more sense when I have some photos.  I've ordered some 0.19" 6061-T6 aluminum from onlinemetals.com.

Oar Construction Man-O-War, 5 Jan 2013 I picked out a straight, plain-sawn 8' Fir 2x4 from the lumber yard's stack of #1/clear.  Then ripped it down the middle and marked where the oarlock "leathers" will be located.  Then turned each down to about 1⅝" diameter in my jig (right) using my trusty ¼" router with a ½" straight bit.  The first rounded oar handle (on the left) shows the 1½" PVC pipe about where it will be located to join the two halves.
To cut the taper where the blade attaches to the shaft, I made up this pattern and screwed it onto the shaft.  Then I cut along the line (well, about ⅛" above the line to allow me to clean up the cut). I used my jig saw so it was a pretty rough cut.
Smoothing it out was fairly easy using a sanding disk on the drill.  I used a template of the shape (made from the ⅛" plywood shown here) to make sure I had it right.	Click on image to enlarge to make sense of it

Here I'm gluing the blades onto the shafts.  I didn't have many clamps so screwed those sticks into the 2x12 plank underneath instead.
 
For the top splines, I'm using ¾" wide 6mm Okoumé.
 
The large round stick on the end (left over from cutting out the tapered pieces) is actually pulling up a stick from underneath.  Each of the ends of the shaft broke under pressure.  The 2x4 fir I used had the tightest grain I could find in the stack.  Spruce would have probably been a better choice but wasn't available.  Anyway, I was able to pull the shaft back fairly close to the blade before the resin set.  Later, I dribbled resin and finally worked thickened resin into the cracks.  After that set, I sanded down the bump.  The thickened resin patch will probably be stronger than the original wood alone.
 
I shaped the "Modified Norse" grips as shown in DeLapp's plans.  They seem like they should be pretty comfortable.
 
See below for a couple photos of the oars in place.
 

Finishing up Man-O-War, 31 Jan 2013 Just bits in finishing up..   Here is the holder (Click on image to enlarge to make more sense of this) for the oar handle.  I used 1" Divinicell, cutting the hole fairly crudely.  After the epoxy set from gluing it in place, I put a generous amount of thickened epoxy in the hole and inserted the end of the oar handle into it, with a piece of plastic grocery shopping bag over the end.  I removed the epoxy that squeezed out before it set.  After it had set and I removed the oar handle, I enlarged the opening a little with a Dremel tool to allow enough play to remove the oar easily.  After this photo was taken, I applied a layer of the 6 oz. cloth to protect and finish off the foam (although simply resin on the foam makes a plenty tough surface).

To finish the gunwales, I used a stick as shown and 36-grit sandpaper to fairly quickly even up the top surfaces and make them level.  Just rest one end of the stick on one gunwale and rub the sandpaper and stick back-and-forth over the other gunwale.   For the hole for the mast, I initially drilled it using a 2¼" hole saw to exactly fit the mast.  Then I fit and epoxied in the mast step square to the mast.  Then I would like to have had a 2⅜" hole saw to enlarge the hole but didn't.  So, I wrapped some sandpaper around the 2¼" hole saw and slowly worked it into the hole until the hole was was about 2⅜".  Then I put 3 layers of the 6 oz. cloth inside the hole, fluting the ends to lay flat on the top and bottom surfaces [need a diagram here].

 

Short break Istanbul, 28 Jun 2013 I got sidetracked by other things - helping out with Sojer Day and such.  Then I went on a trip to the Med - most of it aboard a Crealock 34 :-).  As I write this, I am really looking forward to getting back to Man-O-War and finishing up this project.  I think I was down to one more fairing coat (there's always "just one more") and then paint and fitting the oarlocks.  Then launching (woo-hoo!) and rigging her for sailing.  I should be updating this blog around the middle of July.

Back to finishing up Man-O-War, 19 Jul 2013 OK.  Back ...   Here is a photo of the plywood block for the 3 clamcleats, mounted on the daggerboard trunk.  It is made from 3 layers of the 6mm Okoumé.  Each cleat is angled in 2 dimensions to lead as fair as possible to it's corresponding block at the base of the mast.  The wiggly lines here show the layers of the plywood after shaping it. (Click on image to enlarge to hopefully make more sense of this)   Man-O-War, 1 Aug 2013 After gluing it on, I decided to cut away the top part above the topmost clamcleat.  So it ended up looking like this (after paint):

Here are a couple photos of the oars in place.  Still rough, but hopefully this makes sense.         Got to love that wide angle lens. These were taken with the Canon 10-22mm EF-S.

 

Paint Man-O-War, 31 Jul 2013 I used Pettit Easypoxy for the paint.  I wanted a finish that I won't mind knocking around and repairing compared to say, Awlgrip, that I would want to baby.  Also, it was less than half the cost of Awlgrip.   First, I applied 2 coats of their undercoat #6149 (the 1st coat is shown in the photos above), sanding them reasonably smooth (down to 100-grit sandpaper).  Then I applied 2 coats of semi-gloss white #3106 to the vertical surfaces.   Then I taped the borders for the blue paint I want to put on the horizontal surfaces.  I used ¾" Scotch 3M painter's tape.  I didn't press the tape down quite firmly enough in a few spots and the blue paint managed to seep under it there.  I found that the top from a 1 gallon milk jug was about the right size (~1½" diameter) to use as a guide for cutting the rounded inside corners.  For the rounded outside corners, I used the cutouts from those inside corners, placing them on the spots where the outside corners would be.  And then used them as guides to cut the corners.  I used an Exacto knife to make the cuts.   Then I put 2 coats of Bikini Blue #3229 on the horizontal surfaces (see photos below).   I'll put on a couple coats of Sea Hawk 44 bottom paint later - just before I start using the dinghy.

 

More paint Man-O-War, 1 Aug 2013 Here are some photos with the blue paint on.  I applied it using a roller, then went over that with a brush - what I believe is called "roll and tip".  Either I didn't thin the paint enough or I was too slow in tipping, but the finish came out a little rippled.  If anybody asks (and even if they don't), I'm going to claim that this was intentional.  I think it actually might make for a good non-skid surface.  I didn't want to use sand on the surfaces to make non-skid.  This may turn out to be just about the right amount of roughness for my tastes. Note that I plan to paint the oars yet, so I didn't pay any attention to making them look good (as if they were to be finished clear).  And there is lots of touch-up work to do here and there.

Enough blue for ya?
 
I had hoped to get more done.  Heat, rain, well... the usual excuses.  A couple months ago I made reservations to go down to Panama for an extended stay.  I've been neglecting my Spanish.  I'll finish up - touch-ups, the oars, bits of hardware, the sailing rig - when I get back in February.  Please revisit this page then.  If you have any questions please email me ().  Also let me know if you have a construction blog for your dinghy project so I can add it to the list below.
  The flotation compartments are mainly for ... well, flotation.  But here is my list for what I plan to stash in one of them - stuff intended to be as lightweight as possible, but each providing value in an emergency.  Size is not as much of a concern, as long as it fits through the access port:

• Emergency fishing kit - hooks, line, sinkers, etc
• A small stainless steel knife
• A small water bottle
• One of those waterproof solar-powered flashlights
• A "signal mirror"
• Duct tape - don't leave home without it
• A small aluminum anchor with some ¼" rode
• Mylar tarp - for protection from the sun
• A solar still

Bottom Paint Man-O-War, 28 Nov 2013 I returned from Panama a couple months early.  It's nice to be back :-).   I plan to put on 3 coats of bottom paint.  I'm using Sea Hawk 44 from the boat yard.  It is very effective at keeping stuff from growing on the bottom.  Willard Albury (founder of Albury Brothers Boats) helped me mark the waterline.  We used the same technique the old timers used to mark the waterlines on the original Abaco Dinghies: You use two sticks - one at the transom and one at the bow - set at the height of the waterline, perpendicular to the length of the boat and level with the dinghy's DWL.  Sight from one to the other to make sure they are level with one another.  On these, you run some light cord between the sticks on each side of the hull.  The cord should be lightly touching the hull on either side.  You can then measure the height of the cord at mid-ship to make sure they are the same height from the gunwales on each side of the boat.  One person gradually pulls one of the cords toward the center of the boat along the stick as the other person marks where the cord hits the hull.  You do this for all 4 sections.  The marks are about 6" apart.  The person making the marks holds the cord to the hull where the latest mark falls, so that the cord doesn't "roll up" the hull as the other person moves the cord in a bit more. Willard said when they did this on the old wooden boats, they used to drive in small nails where the marks were made.  Then they would bend a flexible metal rod over the nails and draw a line along that.  That resulted in a very smooth line.   We marked the paint line about 1" above the DWL at the stern and about 1½" above the DWL at the bow.  That's to deter stuff from growing up above the waterline.   Then I sanded down the bottom with 80 grit sandpaper to give the paint something to grip to.  And then taped following our marks and applied a coat of the Sea Hawk primer:
I plan to put on black bottom paint (representing deep water), a light blue "boot stripe" above that (for tropical Bahamian waters) and a yellow stripe at the sheer line (for the sun).  The white of the hull represents the clouds.

Man-O-War, 1 Dec 2013 I just realized that those are the same colours as the Bahamian flag:   :-)

Man-O-War, 17 Dec 2013 Here's the result (just after a good rain so it's kind of glistening):
A couple notes: - The boot stripe is 1" wide at the stern continuing to where it crosses the chine.  Then it flares to 1½" at the stem.  I'm going to wait to see how it looks in the water, but I may flare it more at the bow and stern. - The yellow stripe along the shear is ½" wide. Man-O-War, 6 Aug 2014 I just relaunched her after returning from a trip.  I definitely want to flare the boot stripe at the bow and stern.  It looks pretty puny as-is.  Next time I touch up the blue paint.

Oarlocks Man-O-War, 16 Dec 2013 I launched the dinghy to try out the position of the oarlocks (with them clamped to the gunwales).  The plan's suggested location of 9½" aft of the trailing edge of the thwart seemed as good as any so that's what I ended up using.
I used a chisel and my ¼" router with a straight bit to route out for the oarlocks.  There was quite a bit to remove because the oarlock is a 90° angle and the hull to gunwale top is more than that.   I'll seal the wood with epoxy resin and after that sets up, 5200 to bed the fittings.. just waiting for a dry day :-).		The top screws fall right where the gunwale meets the hull.  Even though the oarlock's side screws will probably keep that seam from opening, to be on the safe side I've drilled those top hole extra large and will use the West System technique of filling them with epoxy resin, simply inserting the machine screws (coated with Pam so I can tighten/remove them later) into the liquid resin, and then letting the resin set up to hold the screws in place.

Boom Man-O-War, 20 Apr 2014

In the minute detail department, here is the end grain from the 2x4 that I chose for the boom.  The wood is fir.  These thin samples were cut from each end of the board.  As you can see, the 2x4 was quarter sawn.  But the grain also has a peculiar curly pattern.  My feeling was that this pattern would add extra strength and resistance to warping.  I asked Willard about it and I think he agreed with that theory.  The board was noticably heavier than it's more normal looking siblings in the stack.  Also, the wood is very hard - apparently being heartwood.  Now I just need to avoid getting bonked on the head with it :-).

Rudder Man-O-War, 24 Apr 2014 For the rudder I liked the trick that Seaweed used for securing the recessed screws of the lower pinion bracket.  I coated the hole with epoxy resin and will dribble more around it to try to seal up the wood as much as possible.  The T-nut is stainless steel, of course.
And here is the aft end of the tiller.  I'm going to secure it to the rudder with a ¼" bolt and a wing nut.
The tiller is cut from the 1-by fir board (a 1x6 I happened to have - the tiller is just 2" wide).  I cut it a little longer than the plans called for - I tend to like a long one on my other sailing dinghy and besides I figured I could always shorten it later if I wanted to).  And I cut those rounded pieces pretty close to the final shape to make it easier to finish up the final fit.	Here is the end result.  I used my router and a ½" straight bit to route out the rudder cheeks where the tiller fits.  I may cut that excess off from the top.  I had allowed some excess in the rough cutting of the boards.  Then when it came time to finishing off the top, I figured "What the heck, let me see how this looks with that extra 'tongue' sticking out".

Mast Man-O-War, 26 Apr 2014
Here is the block for the top of the mast.  It will hold the sheave for the halyard.
I used two pieces of 1-by fir board on the outsides and two pieces of the 6mm Okoumé plywood on the inside.  That way, the space for the sheave (which is ½" thick) was easy to make.  This shows each half made up, ready to be glued together.		Here, the two halves have been epoxied together and rounded down.  I used a chisel and sandpaper to round it ("we don't need no stinkin' lathe").   The lower 3" fits snuggly into the aluminum pipe top piece of the mast.  BTW, I used 3 6'  lengths of aluminum pipe ... (diameters 2¼", 2" and 1¾") as called for in the materials list - while the plan sheet specified 2 6' lengths (diameters 2" and 1¾") and a fir closet rod (diamenter 1⅝") for the top.. a bit of a discrepency that has possibly been fixed since. I'll epoxy it in later - after I see how the sail fits the height of the mast and make any adjustments.   The top 3" is small enough so it fits in the middle section of aluminum pipe - for storage.  I also epoxied a piece of 6mm Okoumé plywood on the top to protect the end grain from the elements.  And have coated the wood with a sealing coat of epoxy prior to painting it.	Painted and inserted into the top of the mast.   I'm planning to leave the aluminum mast unpainted.  One of my goals with this dinghy is to minimize maintenance.  I'll possibly have it powdercoated someday - when I'm near a shop that can do it.

Daggerboard Man-O-War, 29 Apr 2014

For the daggerboard, I used a piece of ¾" blue Styrofoam for the core.  This was the plain, cheap builders Styrofoam you find in Home Depot.  I shaped it with sandpaper on a sanding block (which is very easy to do) and plan to wrap that in 2 layers of 17oz. double bias (+/- 45° stitched to mat) biaxial fabric.   Since I expected to need quite a bit of resin, I chose to use less expensive Polyester resin instead of my precious West System Epoxy resin.  First I made a little test to see if the Polyester resin affected the Styrofoam.  The answer was that it melted the Styrofoam on contact :-(.  Then I tried the Epoxy resin.  No reaction :-).   So, after shaping the Styrofoam with sandpaper, I applied a thin coat of Epoxy resin to it, let that set up, sanded it a bit to remove some bumps, then applied a second coat of Epoxy resin and sanded that very lightly so as not to break the surface.  The result was ready for the next step - wrapping it in the biaxial cloth and applying the Polyester resin to it.  The lesson: if you try to use a foam core, first test a small sample of it with the resin you're planning to use.

Here is the Styrofoam center after precoating with Epoxy resin, with the first layer of biaxial cloth + Polyester resin covering it.  Chad, the manager of Edwin's #2, helped get me started.  First we pulled the material tight over the foam bending it around the blunter, leading edge of the daggerboard.  We used a couple thin strips of wood and the clamps you see here to hold the material tight.  Then we coated the biaxial material on one side with the polyester resin, let that set up, then flipped the assembly over and coated the other side. The resin stops just short of the wood strips.  Once the resin had set, I removed the clamps and wood strips and coated that last part.  After that set, I did the same thing with a second layer of biaxial material.

Man-O-War, 8 May 2014
After applying two layers of biaxial material, there was still enough play when I tried it in the daggerboard trunk for a third layer of material.  I applied it just to the part that will be inside the trunk, plus an inch or two down to avoid a weak edge where the board exits the trunk.  As previously, I used clamps along one edge to pull it tight.  This layer wrapped the other edge though - the aft edge, to reinforce it.. if that makes sense.  I think it is redder in the photo above because I used slightly more catalyst to make the resin set faster.	I figured I'd put a wooden spacer at the top, where the handle is attached, to strengthen it there.  I simply routed the foam out using a ½" straight router bit - centered in the opening.  I used the router's fence, as shown here, to carefully guide me and left about ⅛" Styrofoam scrap on either side (not shown here).  That was easily removed by "pinching" it sideways with the tip of a chisel and then scraping out the remnants.	Here is that spacer block, with the handles on either side, epoxied and bolted to the daggerboard, before paint. And painted.  I guess I was getting eager to try it out and didn't sand the top very smooth.  I'll sand it and apply another coat of paint.   I plan to paint the lower part white but will do that just before I leave for my next trip to let the paint harden while I'm gone.  I figured it would just scrape off easily during the next week that I plan to use it before leaving.

 

Man-O-War, 8 Aug 2014 So, finally got to take her out for a sail.  The daggerboard wants to float up a little (~6") in use.  It has a foam core (albeit with lots of fiberglass biaxial cloth covering it) so this is to be expected.  Having it a little buoyant may be a good thing - to make it easier to raise in the event of grounding.  But, I'd prefer it to be neutral buoyant.  Plus, adding some weight to the bottom will add to stability - can't argue with that.  So, I got a couple (~2 pound each) lead dive weights from the dive shop next door.  Starboard side of the daggerboard. Port side of the daggerboard. To test whether this was enough, I tied them to the bottom of the board and plunked that in the water measuring how much of the board floated above the water compared with the height of the daggerboard trunk.   It looked good so I then routed out recesses at the bottom of the daggerboard for them.  That was easy with a ½" straight bit on my ¼" router.  I routed out most, but not all, of the foam.  I pinched and scraped out the remaining foam with a flat screwdriver.  Using a sanding drum on my Dremel tool, I beveled around the edge of each hole a little to let me feather some fiberglass cloth over the opening.   Then I epoxied the weights in place.  First, I coated Port side of the daggerboard. The white is from the thickened epoxy embedding the weight in the hole on this side. To the right, you can see the outline of the lead weight that was inset from the other side. the inside of the hole and weight with epoxy.  Then I put the weight in the hole and filled in all around it with thickened epoxy.  I smoothed that out so it was a little below level with the board's surface.  On top, I applied 4 layers of 6oz. glass cloth, coating each with epoxy.  Each layer overlapped the beveled edge so that when I sanded everything level later, the cloth would be feathered over the bevel.  After the epoxy set up, I sanded everything fair.

Under sail Cuenca, 3 July 2015 Here's a couple photos of her under sail. Thanks Charmaine (and here) and Rich for the photos.
Photo by Charmaine Albury	Photo by Rich Miller
Out and about Crystal River, 16 Jan 2016 Here's a photo of her alongside ANNIE with a pretty good load.  The black bag holds a folding bicycle.  I think this photo was taken off Matthew Town, Bahamas.   Thanks Jock for the photo.	Photo by Jock Covey

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Misc notes:
	-	Spindrift construction blogs:    All about Seaweed: Building a Spindrift 9ft Nesting Dinghy (w/ enlarged photos)  Expedition Dinghy - Garry Prater's 11N.  I’m guessing I spent between 80-100 hours on mine… (pic) - notes and a photo.  A 12'er shown stored aboard a (large) Crealock Building a Nesting Dinghy - a 9N.  Looks like he used Garry Prater's Perko Clamp trick for joining the halves.  Brian Morris's photos - looks like a nice neat job.  The Cruise of the "Beyond" - an 11N.  Toledo Community Boathouse - Building a B&B Yacht Designs Spindrift 11N  Justin's Spindrift Build ~ A history of my Spindrift 11N build
	-	Other construction blogs:     Minipaw Dinghy "No Regrets" (nice writeup. I like his paint job)     PDRacer, future nesting dinghy

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