Continued from our last episode where I was standing around scratching my head trying to figure out what to use to fill the rotted corner of that window sash.
Just finished filling it with PC-Woody. I ended up making a form out of scrap wood: one L-shaped piece for the window stop profile (more or less), another L-shaped piece of plywood for the sash front surface, and two pieces for the bottom and side. Covered all casting surfaces with waxed paper. Drilled holes in the rotted members, put in 1/4" threaded rod and joined them with an L-bracket and nuts.
The PC-Woody stuff seems OK. However, I must point out to those who might go this route that the stuff is a little hard to use. If you get it nice and warm like they suggest (~80° F), it makes it easy to mix. The problem is that the mixed stuff has the consistency of thick peanut butter, and it's not easy to smooth out the surface (try doing that with a gob of peanut butter sometime): it pulls and sticks, so you can't just screed it flat. So I gobbed it on pretty thick, planning on rasping and sanding it down when set (will wait a couple days for it to cure hard).
But I'm positive the repair will be solid, probably as good as the wood that was there before.
I ended up with the PC-Woody after looking at several other similar products at a couple of local building supply stores. The other ones were in kits, with a sealer included in the box (I bought the PC-Woody sealer separately and used it). The thing about these other products is that they were pretty expen$ive, in the neighborhood of $40-50 a kit. PC-Woody is a lot cheaper: I got the 12 oz. size (2-6 oz. cans) for about $10 each. Only needed one of those, plus what was left over from my little 4 oz. cans to fill the gap (pretty big hole).
I'll report later after I finish up the repair.