PVA vs wax-based sealer

[Karl Best]

I just opened a gallon of sealer I got from Craft Supplies. I must have misordered because I've got the PVA version rather than the wax-based version that I normally use. Hate this stuff -- it takes twice the time to apply because it's so sticky, it glued my rough bowls to the cardboard I laid them on, cleanup is difficult, and the drips on the floor won't come up.

Craft Supplies claims that the PVA cuts drying time by 50% over the wax version; is this true, and how would this be possible?

What's everyone's pros and cons on the two types of sealer?

 

[Rick Urban]

Karl,

While I have never used PVA sealer I will offer this: If any thing will allow them to dry twice as fast, it means the moisture is leaving twice as fast. In general, the object of sealer, paper bags, etc. it to slow the drying process so internal stresses caused by the shrinking cells can adjust without cracking. To take an extreme example just to illustrate my point... If you don't seal at all, it will dry faster than if you do seal, but we understand what usually happens when you do.

The rules change when you start using methods that alter the cells or cell walls.

 

[Karl Best]

Karl,

While I have never used PVA sealer I will offer this: If any thing will allow them to dry twice as fast, it means the moisture is leaving twice as fast. In general, the object of sealer, paper bags, etc. it to slow the drying process so internal stresses caused by the shrinking cells can adjust without cracking. To take an extreme example just to illustrate my point... If you don't seal at all, it will dry faster than if you do seal, but we understand what usually happens when you do.

The rules change when you start using methods that alter the cells or cell walls.

My thoughts exactly. Unless the PVA was porous to moisture, i.e. the same as if it wasn't applied, then drying isn't going to be any faster. Seems to be a very dubious claim.

 

[hockenbery]

Craft Supplies claims that the PVA cuts drying time by 50% over the wax version; is this true, and how would this be possible?

When I used anchor seal it took 12-14 months to dry bowls. Switching to paper bags reduced drying time to 8-10 months
A 30-40% time reduction.

Googled “PVA porosity”. Go lots of hits.
Craft supplies has always been reliable.

 

[DON FRANK]

Karl, I had the same reaction when I first tried it and then saw that Mike Mahoney thins his some with water so it brushes easier. I started doing that and really like it. I think it does a better job of reducing cracks than the anchor seal type sealers. It's my go-to for sealing. I purchase the stuff in 4 gallon cases from Dick Blick art supplies. It's just sold as PVA glue, their brand.

 

[Rick Urban]

I am not an expert woodworker, but I have used thinned PVA glue (Elmers white glue) as a sizing for end grain glue joints. It seems to me, if thinned so it soaks in more, it would get the job done while eliminating the problem you're encountering.

 

[Dave Fritz]

Nice you can purchase in smaller quantities for the hobby turner that don't do much processing of wood. https://www.dickblick.com/products/books-by-hand-polyvinyl-acetate-pva/ If this is what you're speaking of.

 

[Steen Lundsteen]

I just opened a gallon of sealer I got from Craft Supplies. I must have misordered because I've got the PVA version rather than the wax-based version that I normally use. Hate this stuff -- it takes twice the time to apply because it's so sticky, it glued my rough bowls to the cardboard I laid them on, cleanup is difficult, and the drips on the floor won't come up.

Craft Supplies claims that the PVA cuts drying time by 50% over the wax version; is this true, and how would this be possible?

What's everyone's pros and cons on the two types of sealer?

Hi Karl, I have been using Tree Saver Green Wood Sealer from Craft Supplies for over a year now. I have roughed 101 bowls at 10% thickness, and made quite a few rounds at 3 inches in thickness.
I give the sealer twice and haven't had a single crack.
The only one I have experienced was at some 8 inches in diameter and approx. 12 inch high blanks in beech. It didn't go well. These should have been hollowed out first (the trees don't grow into the sky).
I have previously used white joiner's glue, with somewhat fluctuating results.
It is correct that the drying time is reduced with Tree Saver Green Wood Sealer from Craft Supplies, probably around 30 - 50%.
I seal the whole subject twice, and store them outdoors covered.

 

[Bernie Kopfer]

I have used thinned Titebond II but mostly the Craft Supply PVA sealer. And yes, the bowls dry faster than with the wax based sealer. Having not done side by side comparisons with intent to compare I can’t speak to which works better. Spoke with a tech at Titebond and he suggested thinning with alcohol to make the glue set faster. But it seems to me that there are less cracks with PVA. After the glue dries overnight I place the bowls in a paper bag, Amazes me how moist the bag feels for the first couple of weeks. That said Craft Supply is not going to make false claims about a product, and maintain their excellent reputation. It would be nice if they would chime in with some hard data.

 

[robo hippy]

I generally don't bother sealing the end grain, unless the logs are going to sit for a while. If I am cutting up blanks, I round them out and then use the stretch film. I have kept madrone for 6 months that way. I did have a bunch of spindle blanks that I turned and glued the end grain. Who does not have any old glue bottles around???? None of them have cracked yet. I do stand them on end, seal one end, then come back the next day and seal the other end. If I was to do twice turned bowls, I would at least seal the end grain and rim. Maybe put them on plastic to dry rather than paper or cardboard.

robo hippy

 

[Michael Nathal]

Elmer's white glue ("Glue-all", not "School Glue"} is PVA and a lot cheaper than the Blick product. This is what I use, diluted maybe 20-30 %. My experience is that it is about the same as Anchorseal in preventing cracks, although I have not compared drying times. .

 

[Ric Williams]

I've used PVA sealer or wax emulsion sealer on a batch of twice turned bowls from the same wood. FWIW, the ones with PVA sealer did dry about 20-30% faster. The only cracks with either type were on the one's where I left the bottom too thick. Rookie mistake.