Forward bulkheads installed

Finally time to get the remaining bulkheads in place.  First I trimmed a bit off the keel between B3 and B4 to allow clearance for the hatch backing plate that will be in the cockpit sole in that area.  It's much easier to make these change before the parts are installed.  

I then glued down the keel and B2 and B3 using thickened epoxy.  I used a couple sticks to push the center of B3 forward about 1/4" where it was tending to bow backward.

I also attached the cleats that will support the bow transom (bulkhead 1).  As with the seat cleats, I applied thickened epoxy, then used the pin nailer to temporarily hold them from sliding around while I attached clamps.  I like this method better than the suggested method of dry fitting the parts, drilling and fitting screws, disassembling, applying epoxy, assembling with screws, and then filling screw holes later.

  

I then planed the bevels on the bow transom so the hull panels meet up nicely, and installed that.  Again, pin nailer, followed by clamps.

After the glue dried on the joints, I followed up with structural fillets to bond all the pieces into place.  This is looking more like a boat all the time! 

B3 hatch openings cut and backing plates installed

After completing the installation of bulkheads 4 through 7, the next order of business is to install B1 - B3.   However, I wanted to install access hatches in B3, and decided I should do that before installing the bulkhead, as it's much easier to work on now.

I needed to cut out the hatches, manufacture a backing plate for the hatch to seal against, and make hatch stiffeners to reinforce the hatch itself.  I decided to make a router template to make all the cuts.

First I did some paperwork to figure out the template spacer diameters I would need.  I used a 1/8" bit to cut out the hatch, a 1/4" diameter bit to cut the groove for the gasket, and a 1/2" bit to cut the inner rim of the backing plate.

With dimensions in hand I moved to the lathe to cut out the spacers.  I used a template guide with no spacer for the first cut, so just needed to create two.  I used 1/4 aluminum.  In the photo above you can see dimples on the spacer where I hit it with a ball pein hammer to snug up the inner diameter.

I then drew out the template.  The opening size I decided on was 12" x 18", and I needed a line outside that to account for the first template guide.  I then cut out the template with a jig saw, and smoothed it with spokeshave and drum sander.

Then clamped the template to B3, took a deep breath, and cut out the hatches.

As I was cutting out the backing plates, I realized I could also cut the hatch stiffeners from the same piece of ply, using the same template, by making a big spacer (about 6" diameter).  I cut that spacer out of plywood, and it worked fine.

 After cutting out the backing plates, I checked for fit.  Looks about right.

Next I laminated the hatch stiffeners.  I am using two layers of 1/4" baltic birch plywood.  Nice wood.  I would have bought 1/2" thick if it was available.

And then laminated the backing plates.

After cleaning up the glue squeeze out, rounding over the edges, and an overall sanding, I 

installed the backing plates in the bulkhead and cleaned up the glue squeeze-out.  

I had to clampea board across the bulkhead to keep it from sagging from the weight of the clamps!

Nice to have that job done.  There will be a little followup work on these to coat with epoxy, but I can do that after the bulkhead is in the boat.

I'll be able to use this same technique for the seat-top hatches and the cockpit sole hatches.  I can use the same router bits and template spacers, I'll just need to make a new template for different sized hatches.  Should go a lot quicker next time.

First bulkheads installed

It's a milestone!  The boat is now in 3D!  No longer a collection of flat panels, I've finally got some very visible progress.  Bulkheads 4 through 7 and the seat longitudinals are now all in place, glued and filleted.

This was a bit of a nerve-wracking process.  There were a lot of moving bits and some slippery with glue.  A second pair of hands was very welcome.  Once the fillets hardened up, all the pieces are very firmly fixed together and the whole structure has stiffened up.

Working around the limber holes was tricky, and I have a little bit of further work to do here before I'm satisfied.

These fillets are not perfect, but are pretty good.  I can spend a little time removing rough spots after all is hardened up.

Here's a view down the startboard side from the bow.  The round hole is in bulkhead 4 and will take a 6" hatch.

All in all, I'm very pleased with this latest progress!

Bushing rework, Bulkhead 7 modification

I celebrated a little too soon regarding my nicely aligned bushings in the centerboard case.  This last one to be installed had only been curing about 12 hours, so the epoxy was not fully set, and when I dry fit it in the hull and left it overnight it had a chance to sag.  I discovered it the next day when the epoxy was fully cured.

I trial fit the centerboard in the case, and it was not too badly out of alignment, probably would have been serviceable, but I decided to fix  it.

I heated up the bushing and epoxy with my Milwaukee heat gun (very handy tool).  That softened the epoxy up and I was able to push the bushing out of the hole.  When I used the high setting I charred the wood a bit, so I backed off on that.  

I drilled the recess out to 1", which gave me 1/8" around the bushing this time, vs. the 1/16" I had before, and this made it a lot easier to get the epoxy in and poke out the air bubbles with a toothpick.

I still had a couple small bubbles, and a gouged the wood a bit with a chisel.  I'll use a bit of thickened epoxy to fill in those defects.

Bulkhead 7 is the rearmost except for the transom, and it had large lightening holes in it.  The build manual suggests filling those in to form independent watertight compartments in the rear corners of the boat, and after consulting with other builders on the SCAMP forum I decided to go ahead and do that.  Access will be via a hatch on the seat top.

I cut pieces to fill the holes and applied thickened epoxy, then clamped between waxed paper and boards.

Turned out great.  This is right out of the clamps, with no cleanup.

A little scraping and a bit of sanding, and it's ready to coat with epoxy and install.

First dry fitting, and centerboard case work

With the jig done, it was time to fasten on the bottom of the hull. Lined up perfectly centered, the hull panel is held on with four screws through plywood pads and into two cross members on the jig.

I then squared up all the routed aligning indentations with a small chisel, and squared up the corresponding tabs on the bulkheads with a file, and then did a dry-fit of the parts.  That was pretty neat - I can really get a sense of the size and shape of the hull now!

Before gluing any of that in, I need to finalize the centerboard case.  I decided to epoxy the doublers on to the panels before installation.

The next pieces I need will be the solid stock for the ends of the case, and that's still getting epoxy coats, so is delaying the process.  But that gives me time to think about where I want hatches.  

And opportunity to keep applying fairing mix and smoothing that off the rudder and centerboard. With each iteration they get closer to done...

Bulkhead access holes... continued

Tonight I finished cutting out the access holes and cleaned them up.  I sanded to the lines in the corners using a drum sander on the drillpress:

And then a spokeshave made quick work of bringing the straight edges down to the mark:

Following that, I sanded the sharp edges into a nice radius, so these pieces are ready to be epoxy coated.

Bulkhead access holes

I had a few minutes this evening to work on the boat, and so started cutting out the larger access holes in bulkheads 5 and 6 per the latest plans addendum.

I fired up the old Dietz kerosene lantern for mood lighting, and was once again reminded of how much heat a lantern like this puts off.  I think it could take the chill off nicely on an overnight trip with some type of snug tent rigged over the cockpit.