Titebond 3 compatibility with varnish

Specifically Man O War marine spar varnish.

It has turned globs of TB3 semi transparent. Has that been covered anywhere here?

The TB3 had cured for 1 month. Can't tell if it's more rubbery than usual.

Paul

 

Why are you varnishing over glue? Is it a seam?

 

It is a water based glue, so unless it dried completely, it will cause problems.

 

I am varnishing over seams inside the hull. Since the hull is a closed box, and the seams for this varnishing won't be seen (as in using the varnish to seal the wood) I was not being overly conscientious about keeping the glue lines tidy. So varnish was going over some exposed glue blobs left over.

Paul

 

Is there another product available that is water resistant enough for a sailing canoe kept in a garage that isn't epoxy based? I'm allergic to epoxy.

 

Resorcinol glue. Here is one source:
http://www.cpadhesives.com/
http://www.cpadhesives.com/adhesive-solutions#resorcinol

 

I asked my doc about it, as I used a lot of resorcinol when I was a kid and I've had cancer. He sent me to an industrial hygienist who suggested staying away from it. The safety sheet is interesting reading. I should have mentioned that. Sorry.

Has anyone tried diluted TB3 as a sealer? Without paint or varnish on it.

Paul

 

I just read it. That could explain a lot. Resorcinol MSDS below:

http://www.sciencelab.com/msds.php?msdsId=9927245

 

TiteBond III straight will make an adequate sealer, though it's a messy, difficult and costly way of doing it. With some luck, your bubbles should go down a bit, if not completely, as the varnish completely cures. It's permeability will not actually stabilize the surface, but it will keep a high percentage of moisture vapor out with intermittent wetting. It might change color as this occurs, depending on dampness.

Water based clear finishes (acrylics) will have a better time over PVA's then solvent based, but again the moisture will soften the surface of the PVA until it's cured, which also could cause some bubbling and discoloration.

As to what you can do now, well this will probably be a bit of trial and error, with different products. A spray can of sanding sealer may work, with a light coat over the joints to lock them down.

 

Thanks guys. PAR, I'll try your suggestions. And I'll check out to see if there are any type three water resistant acrylics that might work. I just got a very nice note from TB saying that Man o War is mineral spirits based, which have little or no effect on TB3. They put a few chunks of TB3 in mineral spirits for 3 hours and they came out unchanged. They have had no complaints from anyone about M o W varnish's compatibility with titebond3.

 

It turns out that uv will disintegrate TB3. Even fluorescent lights will do the trick, so no sealing with watered down TB.

 

You can paint over PVA's to get the UV protection, though this makes a clear finish difficult.