Oak and epoxy

Rick · Post by **Rick** » Mon Jun 21, 2004 8:21 am

In the previous forum, it was generally agreed that epoxy shouldn't be used with oak, because the acid or tannin in the wood could create problems with bonding. Earlier, I had made some tool handles using oak, by epoxying the saw or knife blade in between two halves of the handle and clamping. These have held up during several years of use with no signs of separation.

Here's another opinion found by googling around:

I have been using Gougeon Brothers epoxy for 20 years on many different woods,
including oak. They have a newsletter that I have been receiving and reading over
these same years. I have never heard of the oak/epoxy imcompatability...maybe I
missed it but it seems something that important would come up often. There is a
problem with teak and epoxy due to the oiliness but they suggested in the past that
you wipe down the teak with acetone to remove oils before epoxying. I have done
this with teak and it worked fine.

http://www.rtpnet.org/robroy/baidarka/1 ... /0157.html

Others have said that red oak will epoxy better than white, because it has a more porous structure, and that sanding oak across the grain will allow for a better bond. And there have been pages warning not to use oak and epoxy as well.

Has anyone actully tried this and had epoxy fail on oak? As I wrote above, my tool handles haven't showed any signs of separation, but they might not get the same stresses that the trim on a canoe would.

Rick

Guest · Post by **Guest** » Mon Jun 21, 2004 11:41 am

After the discussion on the last forum, I contacted Gougeon Brothers to get their thoughts on compatibility of epoxy with red oak. They (very quickly) replied that West epoxy was completely compatible. They were unaware of any problems.

Peter Hyde · Post by **Peter Hyde** » Tue Jun 22, 2004 4:58 pm

Here's a little foolish test you can do to set your mind at ease.
Using regular carpenters glue, glue 2 pieces od 1"x1" oak together on END grain using light clamp pressure.
Do the same with straight epoxy (no fillers)
Allow to set up for a week.
Then try breaking the joints!

Jack · Post by **Jack** » Wed Jun 23, 2004 12:35 pm

That's not the point. The failure occurs, as I understand it, many months or perhaps years later when the joints just let go. At least that was the old wive's tale going around. Also, gluing with epoxy and not using a filler does not make for maximum joint strength.

Jim D · Post by **Jim D** » Sun Jun 27, 2004 6:50 am

I have used RED oak on one canoe, and so has a friend... The problem lies not in the bonding, but in the fact that RED oak is some what porus and in time will split if not sealed real well!!.. So far mine has held up good but I'm still waiting!.. Jim

Rick · Post by **Rick** » Sun Jun 27, 2004 8:08 am

Hi, Jim, thanks for posting. How many years has the oak and epoxy been in use? My guess would be that if the glue joints hold up for a year or two, it will probably be OK after that, since the epoxy will be cured totally and all the breakdown in the epoxy due to acid or tannin at the glue line that can occur, will have happened. It just doesn't seem likely that the epoxy could absorb any more acid or tannin after curing, but I could be wrong on that.

One of the first canoes I had, bought about thirty-five years ago, had oak outwales and the oak held up fairly well, even though the maintenance at times wasn't the greatest. After about 20 years, the oak started to darken and rot at the ends and needed to be replaced with ash. There was splintering due to wear and tear along the edges, but no real splitting. The outwales were one piece, with no glue joints.

Jim D · Post by **Jim D** » Sun Jun 27, 2004 7:25 pm

The canoe with RED oak is about 5yrs. old... WHITE oak is different, maybe more desireable... I saw a mailbox, an indoor mailbox... made with White oak, that was treated with very strong ammonia, this darkened the wood almost like stain!.. Giving it an aged appearance... Good Luck!... Jim