Sunday, November 30, 2008


Since I only have space to work on one float at a time, I switch them out as I'm moving along. This may make the pictures seem like they jump slightly -- I'm trying to not report on progress twice unless I've learned/tried something different.

On this side, I filled screw holes and gaps before trying any attempt at fairing the foam. I think last time I was so excited to see the shape develop that I filled after, and of course will have to sand/fair twice.

I use a syringe with narrow attachment to get the QuickFair into the screw holes. They are deep and narrow so filling them from the 'inside out' is important. Remember that vinegar (any dilute acid) easily cleans tools, skin, and spills of uncured epoxy (which is a base). So, if you have a limited supply of that special tool (ie., the narrow tip attachment) you can reuse it as long as the acid is rinsed off before its next use.

Here I'm pre-wetting the tape for the inside keel join, including an extra layer along each side at the transom. Prepping this area as much as possible before the join obviously makes life easier. PMVB as usual.


My plan is to post-cure the SilverTip laminating epoxy that I am using. When initially researching this, I wanted an epoxy designed especially for a fiberglass composite construction – the skins are the strength, not just protection, as it would be for a wood boat. SystemThree has several options, its PhaseTwo (special order, expensive . . .) and SilverTip. They state, "SilverTip 'Slow' laminating resin excels in application for composite-cored boats, exhibiting excellent mechanical properties, following a moderate post-cure." Moderate means 140ºF for two hours.

Since the foam is a great insulator and the hulls will have limited air flow after being closed up, I decided to cure the interior of the hull before closing it up. A little jury rigging and . . .

It's relatively easy to shape the keel using the guides for frames 2, 7, and 11.

I liked Tor's technique of having the deck flat and pulling the hull against it. My deck was in three parts which I fitted and glued while on top of the hull. It was then moved to the strong back and taped together.
My plan was to put the joining bog mixture on the hull flange and then flip it onto the deck, align the beam mount pins with their respective holes, then clamp with ratcheting tie-downs. After a dry run it seemed possible.

No pictures because we were a bit rushed. I wanted to use a 'strong' material at the flange, but a 'sandable' material at the foam-foam join. As usual, the 10 minute work time with QF was the rate limiting/stressful step.

Of course the question of 'how much' seemed difficult to know. You don't want too little as the deck flange is only two layers of glass, so it's a bit flexible at its outer edge, and not always exactly flat (ie., a slight gap at the inner edge if you put a straight edge across). Given that you can't clean up the inside squeeze-out, you don't want too much. Just the best you can, I guess.

A rush to apply, a two person flip (now at the weight limit of what my wife wants to do), a slight jiggle to align the pin and holes . . .

In the end we had squeeze-out along most of the outer edge. I won't know what the inside looks like until I cut the access hatches. Some areas where I had left the hull planking slightly short (from early planking when I was learning) had a larger area and consequently a void. I think this will disappear when I sand the radius to the deck edge. Next time I think mixing my own bog and having a longer work time would decrease the stress.

I found that it was important to have a slippery material between the tie downs and the foam as this ensured that the force was equalized on both sides, verses tight on the ratchet side and weak on the other.

To make the foam bow caps I first made a blank from scraps four layers thick, then estimated additional pieces for the outsides.

I used a large garbage bag as a 'vacuum clamp'. I think I first saw Meno do this. Two zip-ties with a twist to the bag in-between was adequate since a small leak was inconsequential.

I extended the centerline forward with a straight edge and then a plum line to make sure it wasn't cock-eyed. A little of the QF and . . .

The builder happily shaping.

I used a power planer and longboard to contour the bow. Now we're starting to look like a boat!

I had rough-faired the hull before the deck join. Two passes with the router started the shape of the deck radius. First I used a flush cut bit to remove the edge, then a 45º bit with guide to remove material to make hand sanding easier.