# Epoxy and spar varnish.



## buktotruth (Nov 15, 2010)

Hi everyone,

I'm getting ready to assemble a large outdoor dining table made of quarter sawn white oak. I'm planning to use slow cure epoxy for my glue bc the assembly is perry complex and I need the long open time. I'm planning to finish with spar varnish bc of the outdoor use. My question is, if I pre finish with the spar varnish, will the epoxy still form a good bond? I can tape off any joints if need be, but would rather not if I don't need to. So will the epoxy adhere to the spar varnish?

Thanks for the help!
Jeff

Jeff

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## Dominick (May 2, 2011)

Why use the spar? If your coating with epoxy?
Edit: I read it wrong. Thought you were coating with epoxy. My bad. Lol


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## aardvark (Sep 29, 2011)

Epoxy seems a little brittle for wood gluing , but I might be wrong. I would personally use something like Liquid Nails construction adhesive.
I can't speak for the varnish.


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## cabinetman (Jul 5, 2007)

buktotruth said:


> Hi everyone,
> 
> I'm getting ready to assemble a large outdoor dining table made of quarter sawn white oak. I'm planning to use slow cure epoxy for my glue bc the assembly is perry complex and I need the long open time. I'm planning to finish with spar varnish bc of the outdoor use. My question is, if I pre finish with the spar varnish, will the epoxy still form a good bond? I can tape off any joints if need be, but would rather not if I don't need to. So will the epoxy adhere to the spar varnish?
> 
> ...


I would assemble first and finish after. You could use a two part epoxy suitable for exterior use, TB III. or a phenol-formaldehyde glue (resorcinol).









 







.


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## Hammer1 (Aug 1, 2010)

You can't just substitute epoxy for glue. Use Titebond III, it's simple. I would stay away from a film forming finish like a varnish. It will peel and require stripping to refinish. Why not use an exterior finish like Sikkens, Penofin or a clear deck finish like Defy. You can recoat without stripping as needed.


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## HowardAcheson (Nov 25, 2011)

>>>> So will the epoxy adhere to the spar varnish?

No, not well. Tape off any joints.


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## scsmith42 (Jan 24, 2011)

To me, the issue is not so much will the epoxy adhere to the spar varnish, but will the spar varnish adhere to the wood as well as the epoxy would?

Varnish is not made to be an adhesive; chances are your joints will fail over time due to the varnish not adhering as well to the raw wood as the epoxy or other adhesive would.


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## HowardAcheson (Nov 25, 2011)

>>>> Epoxy seems a little brittle for wood gluing ,

Just the opposite. Epoxy is quite flexible. It's flexibility is one reason it works so well for stressed joints like those in chairs.


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