I'm refinishing the stocks on a few old pump action shotguns. I was thinking of putting a thin coat of epoxy glue or poly stock finish on the parts of the stock that mate with the receiver in order to strengthen and seal. Is there any downside to doing this? I ask because it seems that few if any manufacturers seal the stock surfaces that mate with the receiver or under the buttplate. Thanks for your time.

I do it with a few coats of spray laquer as it is thinner and doesn't build as much

I do in fact epoxy bed the stocks to shotguns and rifles with two piece stocks.

Wrap the stock and metal with tape so that only the joint is exposed to ease cleanup. Use modeling clay to plug any areas that could cause a mechanical lock. Coat the metal (including stockbolt!) and the tape with release agent or Johnson's floor wax, mix up your epoxy (make it reasonably thick so it won't run everywhere) and have at it. Make sure that you keep things muzzle up so the epoxy won't run in and cause a mechanical lock. After 24 hours, put the gun in the freezer (honest!) and you will find it much easier to pop the stock off for cleanup.

It is a bit of extra work, but when I take them apart to do the clean up, the epoxy often shows how poor the original wood to metal contact was! I particularly recall a Mossberg pump that was really bad -- I am still surprised that the wood had not split from recoil!

I wish I had thought to take some digital pictures of this job in the past -- I will try to do so the next time!

John

Minor tweaks in the wood to metal fit can change the stock dimensions dramatically. I often slip a piece of old credit card in the joint to test shoot it. Then it can be jigged up to hold it for glassing if it proves worthwhile (they always do).

Cast and drop can be changed easily this way...
art

For just a sealer, and not a bedding, you can thin epoxy with lacquer thinner to make a watery mixture that will do the job you describe.

Many thanks to all of you for your advice and help.