Interior refit 1970's kit sailboat questions

[Spot]

I decided to pre-drill 5/8" (16mm) and fill and re-drill the 1/2" (12.7mm) holes in the keel board. It worked well to match mark them with a transfer punch ran from outside below up into the bottom of the new keel board clamped into place. Holes were filled in with colored epoxy and hand-cut fiber (forgot how messy that gets). I experimented with a 3D printed button taped into the holes to re-find center after filling. It worked for the most part but could have been done by eye and center punch. Not many photos from the sessions, maybe that is a good sign that I am actually working...?

[Spot]

Keel board is in and glassed.
One layer 1oz/sqft epoxy-compatible mat between hull and board the first day and 3x 1708 -45/45 w/ mat over the top with the middle layer bias cut to make it 0/90 (in line with keel) the next. Fillets (epoxy with glass spheres and fumed silica) were added to the long edges before glassing, short edges to receive some sort of decoration later. Layers were wet out and stacked outside boat on plastic, then folded to get into boat. I used Delrin pins to keep the holes aligned to hull during board attach and bits of nitrile gloves to keep the resin mostly out of the holes for capping. I could have used a bit more radius on the plywood and would have been better off finishing before dark to avoid insects trying to swim in the wet epoxy.

Weather is cooler than I'd like so considering running some sort of heater, perhaps IR bulbs (brooder lights or food lamps) in the cabin after setting the cross pieces. My older tail ends of 2:1 epoxy do not seem to mind 'the cold' and cure normally but the newer clear 2:1 system I have is curing very slowly, which lines up with recommendations by them and by West System for having warmer temps for their clear hardener. I am trying to get a week of good curing temps on the repair before use. If I get the cross members in today and capped tomorrow, I will be just in time.

[Spot]

Some more action from the driveway.
The 3/4" (19mm) marine plywood was not going to bend without cracking so I gave it some relief cuts. The floors are covered with 4oz cloth and epoxy resin on the undersides and glued with mat and epoxy to the hull. The gap between hull and floor is filled in with low-expanding canned foam. The old ones had holidays in the glassing which allowed water to get at the plywood. I am hoping by using the trimmed foam and a resin +glass microspheres + fumed silica 'peanut butter' (fillet material) that the fillet joints will retain resin and remain sound.

[Bowdrie]

I take it that you'll fill all the saw kerfs with thickened epoxy?
You've already got them in place now but should you do anymore similar jobs it generally works out easier to fill the kerfs with the mush first and then install the floor.
That way you are assured of totally filled saw kerfs, (excess squeezes out when floor is bent into the hull.
However, I realize that due to set-up times that an extra pair of hands can become necessary at times.
All-in-all, looking pretty good.

[Spot]

Originally Posted by Bowdrie

I take it that you'll fill all the saw kerfs with thickened epoxy?
You've already got them in place now but should you do anymore similar jobs it generally works out easier to fill the kerfs with the mush first and then install the floor.
That way you are assured of totally filled saw kerfs, (excess squeezes out when floor is bent into the hull.
However, I realize that due to set-up times that an extra pair of hands can become necessary at times.
All-in-all, looking pretty good.

Filling the kerfs in beforehand would have worked great, thanks, I will file that tip for another time. I went back and trimmed foam and peeled tape (the tape seemed almost as much trouble as it was worth) and touched up the foam and filled in the kerfs. I will need to do a little more sanding and clean up before glassing. Nights are supposed to warm up for the next couple days which will be nice for getting the next batch and curing.

[Spot]

More forward progress but not enough to make next weekend's event with the boat.

Looked up an epoxy fillet aka 'peanut butter' recipe and found an old MAS video on YouTube. By volume: 1 part mixed resin and 1 part fumed silica and 2 parts glass microspheres. I had just enough silica left for glassing all of this, so happy not to have to drive or wait for more to come. Up until now I'd just been freestyling the mixes with the jars of filler I bought 10 years ago.

I am thinking on the deeper floors I will need a purposeful relief cut at the keel board. The first one went OK without and the second one seemed to do better with a small cut.

[Spot]

I went for a two-fer today. The 12" (30cm) disposable piping bags for adding fillet material are worth it, less time spent applying and wiping and re-applying and less material used overall. Things were humming along until I found myself pulling up fibers rolling out the laminate. Turns out in my two-fer frenzy I installed the wetted-out laminate upside down or mat side up . It took about 5 seconds to realize I did not want that, and I pulled and flipped them, happy to take the extra transferred fillet material over having two smooth and two furry looking floors. In this case the longer working time of the new epoxy was an advantage.