Which Glue?

[George Sanders]

I am building 2 well covers for a farmer. They will be made from treated 3/4 solid stock mounted on a 2/4 frame that will fit inside the concrete well opening. I am going to make a glue line joint with my router. The 3/4 stock (2 layers screwed together in opposite directions) will overlay the opening and everything will be painted with oil base exterior paint.
My question is what is the best exterior glue to use in the joints? The overlay will contact the cement and be exposed to the elements.

[Mike Lipke]

Polyurethane (Gorilla is one) works well. It is absolutely waterproof. I made some Adirondack chairs 3 years ago, they sit out all the time in Northern Minnesota, and no issues.

It does tend to foam a little when setting up, and can push joints apart, so be sure to screw/nail/clamp. That foaming does fill voids and gaps from cupped wood, so can me seen as an advantage.

[Dave Beauchesne]

Titebond III, which I really like, is touted to be useable outdoors - I built a dovetailed cedar planter 2 years ago; despite being full of damp earth, it still tight as can be.

This product blew away the polyurethane based glues in one of the woodworking magazines a while back - - - - and, it does not foam up
( which I don't like too much ). JMHO.

Good luck.

Dave B

[George Sanders]

Thank you both for the replied. I think I'll go with the tightbond as I don't like what I read about the foaming or the difficulty in cleaning it off of skin.

[Chris Padilla]

Epoxy is the best for outdoors but I question why you need to glue up something like this if you are screwing everything together.

Treated wood is typically very wet and is going to move around a bunch unless you dry it first.

I think I would just use stainless steel or galvinized hardware to put this together but then again maybe I don't understand the full scope of the project....

[Randy Rose]

PL polyurethane construction adhesive

[Frank Drew]

I'm wondering whether you're going to have trouble from gluing the panels in a cross-grain construction. With all that potential movement, something's got to give, right?

Actually, maybe more the farmer's problem than yours :D.

[Howard Acheson]

Frank, you are right. Cross grain attachment can be a problem with changes in moisture. The solid wood cover needs to have both thicknesses running in the same direction. Then, some provision must be made to allow the solid wood top to expand and contract where it is attached to what sounds like a frame.

Personally, I would use two thicknesses of 3/4 pressure treated plywood glued together with epoxy or other waterproof adhesive. Wouldn't have to worry about wood movement that way.

[Cliff Rohrabacher]

Titebond II or, the Gold Standard for inclement weather Resourcinol.