Water based Endurovar over Behlens Pore-o-pac?

[Joe Jensen]

I am building a bath vanity out of walnut. I dyed it with Transtint in Alcohol and I've filled the pores with Transtint colored Behlens Pore-o-pac (oil based). I want a very water resistant poly finish. I will be spraying outside and this week it will be 55-60 degrees out from about 11am until 4pm. I was planning to use varathane oil based poly to be safe going over the Pore-o-pac but I've really liked the general finishes water based products. If I wait 48 hours to spray the water based poly over pore-o-pac am I safe for sure? What about tempurature, water based or oil based better given the lower than ideal temps?

[Jim Becker]

Call me cautious, but I'd likely spray a barrier coat of de-waxed shellac to insure that you get good adhesion of your water borne finish...after you let the oil-based filler fully cure. The combination of water borne AND poly (which doesn't like to stick even to itself...) makes for enough risk that I'd take that cautious route. Note that a barrier coat is just that...a thin application that covers. You're not looking for any kind of "build" with it as that would cause other issues.

[Scott Holmes]

"Very water resistant" and "water-borne poly" don't belong in the same sentence.

An oil-based varnish would be more water resistent. A non poly-varnish made from tung oil would be better than a poly varnish...

Tung oil's true claim to fame is that when used to make varnish the varnish is more waterproof than varnish made from linseed oil or soya oil.

I recommend a tung oil based varnish or better yet a KCMA certified fimish.

[Joe Jensen]

I chickened out and used the varathane. I waited until it was at least 50 outside to spray and it worked beautifly. If only I had a dust free spray booth :(

[Scott Holmes]

50 will take a long time to cure... It will dry to the touch within a few hours; it will take more than 30 days to cure.

Varathane makes a good product. It's not KCMA certified but still a good product. Actually it's one of my favorite polys; which I only use on floors.

[Joe Jensen]

I have a heat pump for my shop and I've been keeping the shop at 72-75F. Seems to cure pretty well overnight.

[Scott Holmes]

Overnight at 72 degrees it has only just begun to cure. Curing takes 30 Days +/- depending on film thickness, temp and humidity.

A fan blowing across the dried finish will speed the curing.

HINT: As long as you can still smell the varnish when you sniff it up close: it is still curing. The off gassing smell is the proof it's not finished curing.

[John TenEyck]

Scott, there are several WB clear coats, including poly based ones, that meet KCMA standards. I would choose one of those any day over a solvent based varnish for a spray application.

John

[Scott Holmes]

Agreed; that's why I said better yet a KCMA certified fimish... I often use some of the high tech KCMA water-borne finishes.

I don't see anywhere that GF ENDURO-VAR is KCMA certified. Sounds as though the OP has already finished irt using the oil-based poly.