Initial gluing, day two: the bottoms

After lunch today (Sunday), I went back downstairs and cautiously removed the cinder-block weights from the 'scarfs' I glued yesterday. The two long (17' or so) sides look good and came up off the plastic with no problems. There is a fair bit of excess glue in places, so there's a lot of sanding in my future, but the lines and seams look good.

Now on to the bottoms.

I'd thought that I would have to do these in two stages, due to having only two sheets of plywood on the floor to work on. But then I remembered there was a sheet (and a half) of same-thickness ply left over from the box the kit came in, so I tried laying this down and played around a bit with positioning and -- amazingly -- I found I have room for both bottoms. So: more or less a repeat of yesterday, though it all went quite a bit faster (and with less wasted epoxy) due to experience, etc.

I did have to make up two more plastic-covered boards to act as clamps; the two boards I used on the sides will not span both bottoms as they did both sides. And more weights, for the same reason (two per board).

Some remarks about epoxy: This stuff is something I've been reading about for several weeks while waiting for the kit, and frankly I was somewhat dreading it: many, many warnings about safety (avoid all skin contact) and working fast (lest it "go off" on you and be wasted). I was pleasantly surprised to find that -- so far at least -- it's not terribly difficult stuff to work with.

I'm using epoxy supplied by B&B, who also thoughtfully supplied "calibrated" pumps that fit in the jugs. The "calibration" is a matter of a plastic sleeve that's been glued onto the hardener pumps that acts as a 'stop' preventing the pump from being depressed more than halfway (this epoxy formulation is 2:1 resin:hardener). So, mixing up epoxy is a matter of:

• N pumps of resin (N for me has been 3-5)
• Same (N) pumps of hardener (each pump being half as much as the resin)
• Mix thoroughly (I've been timing myself at about 3 minutes)
• Go to work

Going to work, where gluing the sides is concerned, means: first, apply enough epoxy to the scarfs to "wet out" the wood. This means: brush it on until the wood looks wet. (The theory here is that this will prevent the wood from 'robbing' some of the joining epoxy by soaking it up.)

Then: back to the mixing table, to thicken the epoxy with cab-o-sil (fumed silica...whatever that is...seems to be basically finely-ground fiberglass). I've been satisfied with a 'honey' consistency for joining. Then, back to the joins, and apply the thickened mixture to both scarfs, then put them together, fasten and clamp.

I've been using disposable 'nitrile' gloves from Home Depot (container of 50 pair for about $10?) and 2" disposable foam brush. I'm mixing in a recycled margarine or yogurt container, using a 'tongue depressor' type stick.

A couple of tricky issues:

1. I'm using my cordless drill to sink drywall screws as fasteners (before "clamping" with a board and weights.) Yesterday, I pretty much mixed the 'apply thickened epoxy' and 'sink the screws' step, and the result was: a sticky cordless drill. I was OK the next day, but not ideal. So: today I separated these steps, and changed gloves (discarded one pair, put on another) before drilling. Much better.
2. Yesterday, I had a lot of squeezed-out epoxy after sinking the screws; I made a half-hearted attempt to smooth these out with my gloved finger (thus the sticky drill), but the result wasn't great. Today, I tried using the tongue-depressor stick as a scraper, scraping up the excess. This seems to work well.

The other thing I've read about epoxy concerns the "fast" vs. "slow" hardeners. Probably has to do with the temperature I'm working at (November in Vermont, in an unheated basement: high 50s, maybe 60.) But I've used only the "fast" hardener so far, and I've not felt rushed. I'm a little worried that the "slow" hardener, as the winter comes on, will be very slow indeed.
Enough for now.