Mike's journal

Dinghy Project 3

You can never have (or build) too many small boats :-). 
Here is my previous dinghy.  Here is the one before that.
 
This one will be a Spindrift Dinghy 11N, another stitch&glue nesting dinghy.
  The plan is to be pretty similar to the 10N I built a couple years ago, with the following changes:

• 11' long instead of 10'
• I built the 10N "like a battleship".  On this one I plan to use less fiberglass to protect the surfaces.  I think I'll use 4oz cloth instead of 6oz.  And use it on just the bottom, the sole and the tops of the thwarts (seats).  The downside is that I will need to check the surface for breaks and checks from time to time.  On the 10N, this was not necessary.  There's no free lunch.

I shipped the materials over on the Duke from West Palm Beach to Marsh Harbour.  After clearing customs in Marsh Harbour, they were put on the cargo boat to MOW.  Here they arrive at the Public Dock on MOW.  The Public Dock is just a stone's throw from Edwin's #2 where I will do the construction.

I used the pallets on which the material was shipped for my table - simply resting them on cement blocks and shimming up as necessary.
I then stacked the plywood on top of the pallets (with a sheet of scrap ¼" birch plywood between the bottom piece of plywood and the pallet to protect it).
To the right is the marking on the plywood. Click on the image to enlarge.   World Panel Products said it was "from a Greek mill, Mourikis. It is BS1088 and Lloyds registered".  I think it tends to curl up in the sun more than the Garnica plywood I got from them last time.  Once it gets stressed into shape, epoxy resin applied and painted, I assume there won't be any of this.  But it still makes me wonder.

The first thing to do is join 4' x 8' panels to 4' x 4' panels (ie. a 4' x 8' panel cut in half) to make two 4' x 12' panels.  I made scarf joints in the panel edges using my ¼" router with a ½" straight bit.   I am using a 12:1 ratio scarf - that is, a 3" overlap.
Here the panels have been glued together with epoxy resin - with first a coating on each surface of the joint, then a coat of slightly thickened epoxy resin in the joint to take up any voids.   I screwed in a couple sheetrock screws - one on each end of the joint - to hold the panels in place while the epoxy sets.  I put plastic sheet above and below and between the panels to keep things from sticking together.
I left it overnight with some weight on the joint, while the epoxy set up.

I cut out the pieces of plywood as specified in the plans and attached the sides to the bottoms using 7-8" lengths of 3" fiberglass tape as the plans suggest.  I may have been a little too forceful (errrrr, careless) when trying to unfold them in the "butterfly step", but all 4 pieces of tape ripped IMO way too easily as we were "unfolding" the hull.   On my previous dinghy, I used West System 3" Episize Glass tape.  On this one, I bought the 3" fiberglass tape from B&B.  I think the West System tape was appreciably stronger.  The tape from B&B wets out much more easily, FWIW.
To recover and try again, I sanded off all the old fiberglass tape and resin.  For the second try, I used two layers of fiberglass tape on each side.  In addition, I added a bunch of 12 gauge copper wire ties between the panels.  Click on the image to the right for a better view.

Chad, the manager of Edwin's #2 helped me unfolding the hull in the "butterfly step".   The photos to the right show the hull after making the initial fillets between the wire ties.   I checked for racking using fishing line run diagonally across opposite corners (click on either photo to enlarge) and observing the difference between the lines where they cross.  To remove the ever so slight twist (maybe ¼" difference where the fishing line crossed), I simply elevated the stern corner of the low side.
Below are some photos from the construction.

Looking down the center of the interior from the stern.

Reinforcement on the forward side of the forward bulkhead. I probably could have saved a few ounces with less wood here.

I used a couple sheetrock screws on either side of the nesting bulkhead to hold it in place against the floor. They are fastened to 12 ga. copper wire which passes through the bulkhead.

Here the gunwales have been glued onto the hull using clamps every 6" or so.  Again, I checked for racking using the fishing line before we started to glue up.   I had pre-drilled the holes for the screws fastening the gunwales to the breast hook (ie. a dry fit before applying resin) so that all went together easily when it came time to glue everything together.  I didn't install the knees until after the resin attaching the gunwales had set up.  I think that made it a lot easier and didn't take anything away from the results.   Chad with his father, Blake, helped me install the gunwales.  This helped immensely.  And it was a real treat to have these experienced and most capable guys help.   Chad and the boat yard were very gracious in putting an unused flybridge over my work area to give me some shade.  Even though it was still only April, the sun and heat were already getting strong.

After the gunwales had set up, I flipped the hull over, rounded over the chines using a small block plane and sandpaper, and then glued 3" fiberglass tape over the joints.   Then Chad helped me put the hull upstairs in Edwin's #2 for storage until I come back in December.

Lake Placid, 12 June 2016 Even though this 11N is only 1' longer and just 4" beamier than the 10N I built a couple years ago, it SEEMS SO MUCH LARGER inside.  I can't get over it.  BTW, the freeboard is about the same - I had added 2" to the 10N's freeboard. Model Length Beam Height 10N (plus the 2" that I added to the freeboard) 10' + ~1" 4' 2½" 21½" + 2" = 23½" 11N 11' 4' 6½" 24" Source: bandbyachtdesigns.com/spindrift/

Lake Placid, 13 May 2018 Well, it's been a while since I have updated this page.  I didn't work on the dinghy at all last year - instead, spending all my time on MOW on the Man-O-War Boat Builders' Memorial.  Culminating in a nice dedication ceremony.  This year, we put a thatched roof on it.
But, this year I was also able to finish up and launch the new dinghy. She is almost identical to the last dinghy.  Here is about the only difference...   I again chose to make the thwart a permanent fixture (the plans call for a removeable, drop-in board for the thwart).  The daggerboard trunk is shown here.  The clamps are holding ¾" x ¾" strips of wood (glued to the bulkhead with epoxy resin) that will provide a surface to glue the thwart to.
I used one layer of the 6mm plywood for the thwart.  The ends are glued to the sides of the dinghy using thickened epoxy fillets.  The front of the thwart has 1x2 Fir supporting it.  Thickened epoxy fillets are used throughout.   The thwart seems to be plenty strong and rigid in use.

Some thoughts, now that she is launched:

• She is noticeably larger inside than the 10-footer and a little easier to rig for sailing because of that.
• She is, like the 10-footer, nice to sail - well behaved downwind and on all points of sail.  She is easy to come about.  I feel she points high into the wind.  I think she is a little stiffer than the 10-footer, probably because of the slightly wider beam.
• Maybe just a feeling, but I think she is a little faster than the 10-footer.  I was hoping to get her to plane under sail but no luck yet.
• Even though she is probably not a lot heavier than the 10-footer, I am finding her much harder to carry about on land.  With the 10-footer, I was able to carry each half up a flight of stairs by myself to where I stored them.  This one, not.  I may have more success if I make up lifting harnesses to move them around on land.  I haven't tried hauling the halves up on deck yet.

I'll add some photos here of her under sail, next year...

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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-footer 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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