Polyurethane Glue for Exterior Door Construction?

Polyurethane glues foam to fill voids, but the foam has little strength. Epoxy is a better choice for mortise and tenon joints. March 25, 2010

Iím building and entry door for my house, 2.25 x 36 x 96 solid makore. It will have a cope and stick profile plus I will use 5/8 x 5 dowels at all joints. Iím considering using Gorilla Glue because my dowel holes are 1/16 oversized to allow for adjustments. The way the glue expands, it should hold that dowel in place really well. Iíve used the glue before on cabinet doors and the only thing I donít like about it is that it foams out from every crack and itís a pain to clean up later. Iím guessing it will take me about 15 minutes to assemble the door before Iím ready to clamp it, so Iím in need of a glue with at least that much open time. Iím a beginner so any advice would be appreciated.

Forum Responses
(Adhesive Forum)
From Gene Wengert, forum technical advisor:
Because this is a one-time event, I would think that a slow curing epoxy might be a good choice. Another choice is PL-400. You might find that a different PUR adhesive will work better, so read the labels on the possible adhesives to make sure that it will do the job you want. In any case, make sure that you have really good ventilation as the adhesive you mention does emit some very noxious fumes; so does epoxy. Avoid skin contact.

From contributor G:
Solid makore - hope you have floating panels. West systems epoxy would be better than Gorilla Glue, has a higher heat threshold.

From Jeff Pitcher, forum technical advisor:
PUR would not be appropriate for your construction. Although it does expand, the part that foams (or expands) has no real strength. Your dowellís would be loose in no time. You should go with an epoxy.

From contributor P:
The foam part of Gorilla Glue has practically no strength, so it can't be used in your oversize holes. If you get larger dowels for the holes you have cut, you might get away with it. Generally I use PL Premium Polyurethane construction adhesive when a poly glue is required. After you have used a half tube, saved the rest, and find the nozzle is hopelessly plugged, drill/punch a small hole near the nozzle end, and you will get more out of the tube. Just keep working down the tube until it is gone.