Stabilizing Punky Wood

[Edward Weingarden]

I've got a really nice piece of spalted maple I plan to use for a hollow form. After getting it into a cylinder there's still some areas of punk. I've searched the forum on stabilizing punky wood and found a few different methodologies which include using sanding sealer, thinned brushing lacquer, and water based poly. My questions are as follows:

1. Do I apply a stabilizer at the cylinder stage, or wait until I've shaped it?
2. Will either sanding sealer, thinned lacquer, or water based poly just coat the surface, or will they penetrate to any degree?

Thanks

[John K Jordan]

There was another thread about this recently, but it might have been on a different forum. What I do varies with the wood and the problem, but for the worst cases I apply thin super glue which usually soaks in a lot, let cure, make a cut or two, then reapply as needed. This method can start with very soft punky wood and end up with a surface as smooth as glass.

JKJ

[Joe Bradshaw]

I have had some success using Minwax wood hardener. I would like to try it in my vacuum pot and see if I can get complete penetration. You can also use Cactus Juice resin, but, that would involve more time and money. I had good luck stabilizing a really punky piece of spalted pecan. I rough turning the piece and then stabilized it. It is like turning plastic then. Good luck.
Joe

[Brice Rogers]

I don't have advice to give, but would like to share one of my own experiences.

I had a hollow form 8 inch vessel of Liquid amber that was spaulted and I was getting tear out. So I brushed on some Minwax solvent based wood hardener. It soaked in like water being poured into dry sand or onto a sponge. I applied it to the softest portion of the top as an experiment. I later turned it a bit and found that most/all of the tear out was fixed. So then I declared the stuff a success and decided to liberally coat the whole thing. About 5 minutes later, as the piece was sitting in an aluminum catch tray. I started hearing cracking sounds. It was horrible. I could see the wood moving and cracking. I had a number of open cracks 5/16" wide. The opening was cracked and oval. In disgust, I covered it with aluminum foil and left it sit for a day. The next day I looked at it again and found that it had stabilized a bit and the cracks were "only" 3/16" wide . As practice, I ended up filling the cracks and finishing it. It turned out okay (I guess).

I'm not sure exactly what happened - - whether the acetone based minwax wood hardener was being absorbed differently in portions of the bowl (leading to stresses) or whether something else was going on. I would be interested in knowing from someone smarter than me what may have happened.

[robert baccus]

Try acetone thinned polyester resin(as in fiberglass) in a vinyl bag overnite. After roughing out to 1" or so. Hard as a bowling ball and no discoloring.

[Edward Weingarden]

Does the Minwax Wood Hardener leave the surface unable to absorb finish even after you do your finishing cut?

[David Reed]

No idea what happened with Bryce's piece but I have used Minwax several times and am sold. I turn to about 1/8-1/4" of final size. Soak by heavily brushing on several applications soaking thoroughly. Turns very well. Careful with sanding as overheating seems to melt it and smudges some if over done. Finishes nicely but does not penetrate, but then again, doesn't need to penetrate.

[Robert Willing]

No idea what happened with Bryce's piece but I have used Minwax several times and am sold. I turn to about 1/8-1/4" of final size. Soak by heavily brushing on several applications soaking thoroughly. Turns very well. Careful with sanding as overheating seems to melt it and smudges some if over done. Finishes nicely but does not penetrate, but then again, doesn't need to penetrate.

I do the same thing in fact I also coat the outside of the bowl if I am going to leave the bowl on the lathe overnight because it keeps the wood from cracking on wood that is not completely dry. I have not tried this on wet wood but that is my next experiment.

[Peter Blair]

At our last guild meeting someone mentioned that one of the big box stores is now selling a different type of wood hardener that apparently consists of plexiglass or lexan dissolved in Acetone. It report was that it worked wonderfully but be sure to use it outside or in a really well ventilated area and as you all know Acetone apparently soaks directly through our skin and can cause all sorts of problems so good gloves and eye protection et all!

[Edward Weingarden]

Thanks for the info. I think I'll try the hardener.

[Olaf Vogel]

Try acetone thinned polyester resin(as in fiberglass) in a vinyl bag overnite. After roughing out to 1" or so. Hard as a bowling ball and no discoloring.

Interesting...i wondered if the Minwax hardener was something like that. I'll have to try mixing it.
i've had great success with it, but didnt like the cost. As mentioned the pieces were hard, no tearout and easy to finish.

A friend is a chemist and said they used acetone to clean their hands all the time. Very drying but not hazardous.
https://www.ccohs.ca/oshanswers/chem...s/acetone.html

Nautious and stinky, but not dangerous.

i cam imagine that if its applied to a piece thats still wet, it could displace the water and hyperdry the work.