Sealing Splated green wood

I'm new to woodturning and I recently acquired some logs that have just started to rot. There is a lot of spalting on some pieces and I want to seal them for later turning. I read somewhere that I can use latex house paint as an end grain sealer. Is this a good idea and is it going be sucked up into the wood in any way. Will sealing stop the rotting? Would it be wise to cut the short logs up into turnable pieces before I seal them.

Thanks

"Logs" of what length and species? Is the bark firm or loose, and where have they been?

Logs with firm bark can be left unsealed, the end trimmed and chunks taken off as required, with seal on the fresh cut. The spalting will cease when they dry below about 20% moisture, and the extent of the spalting depends a bit on where they've been. For instances, logs lying directly on the ground should have spalting on the low side pretty much full length. Logs up on skids may only have significant spalting for the first foot or so from each end.

IF you buck them to width plus about 3", you should coat the ends and saw through the heart to minimize drying damage, but the best thing to do is to rough them out thick - rule of thumb is 1/10th diameter - store where they'll dry slowly, and turn to true in maybe six months or so. Lot of different "methods" to control drying damage. All based on maintaining minimum moisture gradient from inside to outside. Once you take the interior out, no more moisture can run from within, so you slow the loss by humid circumstances, occlusive coatings, or other methods, according to others.

If you don't care about round, you can turn them thin, and depending on grain orientation and species, there may not be enough internal stress to significantly deform them or allow a steep gradient to crack them. Warning, though, severe spalting is a challenge to keep from "pecking out" the more decayed regions, especially when damp.

The only difference between sealing a spalted versus a non-spalted log is the problem of continued rot (Spalting is a decay process, of course) with the moisture being trapped inside by the sealing. A large problem with spalting woods is getting it stopped before the wood is fairly unusable. I'll assume that you have the spalting where you want it (percentage of spalt per piece of wood) and are concerned about letting the spalting continue any further. If this assumption is incorrect, then just seal the endgrain and/or treat it as you would any other piece of non-spalted log. It'll spalt some more, sure, if other conditions are right as well and depending on how much it's sealed and the other conditions, it might not continue past a usable stage. On with my first assumption...

The best thing to do is to cut the pieces up into turning blanks and then kiln dry them. You won't need to seal them this way. If the spalting is quite advanced (but still usable wood), it doesn't take nearly as long as an unspalted piece. No need to seal with this procedure.

Next best thing to do is to cut them into turning blanks a little oversized (so that what cracks do develop, can be cut away) and don't seal them at all.

Next is to cut them into turning blanks and seal the endgrain "lightly" with just a thin paraffin wax. It'll still let moisture through but maybe not enough to cause too many cracks.

I would not recommend sealing the entire thing up UNLESS you can get the logs really really cold. The amount of cold depends on the thickness of the log pieces. Thicker pieces might still be warm enough (and with it completely sealed the moisture is there) on the inside to continue spalting.... around 80F ... for some time.

The use of Latex house paint is one of last resort as far as I'm concerned. It'll work .... not real well but it's better than nothing at all. It'll penetrate most of the local domestic woods (oaks, hickories, osage orange, walnut, etc.) about a quarter of an inch at most but that's about it. Next would come the various waxes (paraffins, carnaubas, wax/oil blends, etc.) and then the commercial wax emulsions. I use a variety of these approaches on my non-commercial spalting operations mainly because I have a LOT of stored up shop-made sealer that I used to use for the commercial operations.

Good luck,

- Andrew

In addition to George's and Andrew's replies I'd like to add that latex paint hasn't worked well for me at all. What's worked beautifully and is quite inexpensive if you or a family member is a yardsailer is to look for a 2-3" deep electric fry pan (the one's I see (and use) are about

12"x12"). Also have your scrounger look for candles. People sell those big column candles for a buck or so; save all the holiday candles you can get a hold of; etc. Melt them in the fryer on low heat and walla! you have a bomb-proof end sealer. Just dip the ends of your logs into the pan for a 3 or 4 seconds and let the excess drip off. Once the wax has hardened give it a very quick second dip - just in and out.

When I have logs too large for the fryer I'll resort to an emulsion sealer like AnchorSeal as I've found the fryer wax doesn't adhere well to the log when it's painted on.

_____ American Association of Woodturners Cascade Woodturners Assoc., Portland, Oregon Northwest Woodturners, Tigard, Oregon _____

Another option is to freeze the logs. This will stop the spalting process. Woodturners should all have large walk-in freezers, just in case the perfect log comes along.

I live in one, though it's going to 34 F today, and cutting frozen wet wood is NOT my favorite thing at all.

Couple more days and the cherry chunks that got buried in November should be uncovered for roughing. Saw 'em peeking out on the way to the mailbox yesterday. The butt log's still in the woods, and that'll be a couple months before we can get the skidder in....