: I want to join a 1" wide by 1/4" thick by 8 feet long
: strip at a right angle against a board that is 3" wide by
: 1/4" thick by 8 feet long, creating sort of a "T"
: profile.

: I have planed the strip edge virtually flat and straight. But my
: board is not perfectly flat - I have no planer machine and my
: hand plane tool is not good for that 8 foot by 4" wide
: board. I'll use a long sand block to smooth out the small ridges
: but the board is pretty much as it came out from my table saw -
: with some hills and valleys that sanding will not fix.

: The question is two-fold. First, would I be better off using wood
: glue (Titebond III) or epoxy?. And second, would thickening the
: chosen adhesive with wood dust collected from my table saw be
: fine?

: This needs to be structurally as strong as the wood will be if
: possible - I don't want it to break at the glue joints. Would
: that be possible without a perfectly tight joining area?

: Thanks!

Epoxy is a pretty good gap filler, better by far when thickened. Wood flour is often use for thickening but it's very fine, finer than that from the table saw. I prefer microfibers, basically ground up fiberglass as it's considerably stronger. I'd use epoxy and pre-coat the foam first, wood too while you're at it, then once it's initially cured bond the two together. It's tricky bonding to foam that has little strength, it wants to dent and create air pockets with little strength between it and the wood, precoated it's bonding surface is considerably stronger. Don't wait long after the initial cure to bond the two or you'd have to sand the pieces, next day is fine.

Bill H.