Another thread reminded me of a long-standing question I have about glue. When would you use two-part epoxy instead of carpenter's glue for woodworking and vice versa?

Mike, over the years I have used epoxy for just about all my boatbuilding endeavours. From sticking the wood together to sheathing hulls with fibreglass.

You might also use epoxy for glueing up wood like cocobolo, as it is a waxy wood. Ordinary glues don't work well in a case like that.

If the wood you are glueing up is not going to be subject to being immersed in water, then most standard carpenter's glues will do the job.

As a general rule, two part glues are usually water resistant, not necessarily fully waterproof.

I would think that most folks could manage with any of the regular carpenter's glues for just about everything that they make.

Keith, are you saying that epoxy is overkill for most woodworking projects? That is, if you were overly anal retentive, would you use epoxy more often? In what cases would carpenter's glue be better than epoxy, other than cost and hassle?

Red cedar, teak I think, cocobolo and a few other woods tend to be oily which means regular glues don't stick as well. These are good candidates for epoxy although wiping them down with acetone before gluing will help regular glues to bond better. Epoxy with filler in it is good for loose joints like many chair repairs require.

I tend to use epoxy where it is appropriate only. I don't use it just for the sake of doing so...it doesn't make any sense.

I wouldn't say that carpenter's glue is better than epoxy, or vice versa, just different glues.

There are a few two part glues which I have used over the years, and they all tend to be more water resistant than one part glues.

I will say this, because I have used literally barrels of epoxy over the years, I really do like the stuff. Yes, it is more expensive, (as are all the two part glues that come to mind) yes it is a bit more of a hassle to use, but once you get really used to all its' properties, it is a really good glue. It isn't just a glue...you can use it with fillers to make fillets - for example - when boatbuilding. That wouldn't be glueing anything together, just making a nice smooth inside corner. I have also been known to use it as a finish on western red cedar when the item will remain inside.

Pretty much all the modern glues are stronger than the wood they glue together. So at what point do we really need more strength?

Out in the shop I presently have epoxy, Gorilla Glue, the various Titebond's, 202GF, several of the typical carpenter's white glues, an unnamed two part white glue by Nacan and who knows what else.

One thing I will add about epoxy is that you can use a variety of thixotropic agents with it. Cab-O-Sil particularly sands to an extremely smooth finish, just like glass.

I see that Chuck has a post here, which I will respond to momentarily.

My general rule is dissimilar materials I use epoxy

Chuck, I haven't found red cedar to be particularly oily as such, as it is a very dry wood. Yellow cedar is a different kettle of fish.

There's no doubt that several of the exotic hardwoods will benefit from the use of epoxy. I typically find that the more dense the wood is, the better that epoxy does its' job.

We used a lot of Burmese teak on the big custom yachts I worked on in Vancouver, but that was before the days of common epoxy use. That was quite an oily wood...dense, but quite soft.

Bill, do you mean two different types of wood...or perhaps something like glueing wood to concrete?