# gluing varnished wood



## HokieMojo (Mar 11, 2008)

Everyone's been real helpful here, but I could use some more advice related to a mistake.
1) Let's assume that a friend of mine applied an oil/varnish blend (watco danish oil) to some pieces of wood that were going to be joined using mortise and tenon joinery.
2) lets assume that this friend accidentally got a significant amount of the finish on the tenons and it has cured
3) lets assume that these joints are structural and need to be strong
4) lets assume that the friend in question is actually me

I wanted to get some thoughts about the best way to fix my poor work. Can I still use titebond glue or have I essentially sealed the wood so that it will not penetrate? I work about trying to sand off the finish because the jointes will then fit way too loose. Maybe a quick scuff sanding followed by something like gorilla glue instead of titebond? I'm really desperate. Any help you guys can provide would be greatly appreciated.

Ugg, I can't believe I let this happen. I thought I wiped everything down well to avoid running of the finish, but it still happened and ran onto the sections to be glued.
Thanks in advance!


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## SteveB (Apr 17, 2007)

I would use extremely coarse sandpaper to make cuts through the finish without actually changing the dimension. Your standard glue will probably work just fine, then.

You can consider pegging the joints. I just did this for the first time with through-tenons on a workbench, and I didn't really need glue at all. I only put glue on the pegs.


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## JohnGray (Oct 6, 2007)

If you want a good bond with end grain you have to remove the varnish, trust me "been there done that". The peg idea is great and I've solved the problem several times with my finish nail air gun then filled the nail holes with "hole and nail set" pencil from the local BORG.


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## PetVet (Nov 7, 2008)

You could also convert to loose tenons, but I think I would peg them, unless you really are worried about the stress they will take.


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## Critterman (Dec 20, 2007)

Jo, don't feel bad we've all done it :>) good suggestions on top, but this is what I would do. If the mortise is OK and you've already fitted your tennon (I assume) then I would try to clean off as much finish as possible then cut the tennon smaller, laminate it to size and there you have it. Do both sides if you can, but if your working with a thin tennon that might be difficult. Also, getting the right thickness laminate can be difficult. I don't have a drum sander, and I don't remember you saying you did, so I add a piece of MDF under a board through my planer to get it down thin enough. That's what I would do, that way you have raw wood for all the glue surface, and since the glue is stronger that the wood these days, no strength problems either.


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## foodog (Jan 7, 2009)

Just my two cents….awhile back I was bored and got curious about how well my glue would hold up on a sealed and stained board. As an experiment I took a piece of solid oak and sealed it with some sanding sealer then put a coat of gel stain on it….let it dry completely and then glued a piece of scrap to it using tightbond II….clamped it and let it set. Then tried to remove the scrap, first by hand then by hitting it with another piece of wood….then with a mallet…..finally ended up putting it in a vice and hit it several times with a ballpeen hammer before it broke loose….but not without taking some of the stained board with it. My conclusion….I wouldn't worry too much about it… you could always run a test yourself to be absolutly positive


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## HokieMojo (Mar 11, 2008)

foodog,
Thanks for the advice. Here is what I just did (JUST did). I scuffed the board lightly and applied tightbond 3 (neeed the open set time). Then I clamped everything up. The tenons are not a perfect fit. they don't reach teh full depth of the mortise. What I decided to do was take some gorilla glue and drip that down into the gap. I hope that helps to pick up where the wood glue left off. We'll see what happens. Between the two, I hope I've got plenty of gripping stength. Thanks to all for the posts. I really appreciate it!


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