Nicely Spalted or Plain Old Rotten

[Maurice Mcmurry]

The poison ivy and stinging nettle have died so its nice to work in the woods again. Several dead, standing Elm trees came down in summer storms. Quite a bit is spalted, some is rotten. Is there a guideline for too far gone? Some of the interesting looking wood is quite soft. I thought the billet this Lamp came from would not stand up to turning. I have more like it and a lot that is even softer. I am trying to pick out a few good ones to dry. is there a test I can do, like ability to hold a nail or screw?

489830

[John K Jordan]

… Quite a bit is spalted, some is rotten. Is there a guideline for too far gone? Some of the interesting looking wood is quite soft. I thought the billet this Lamp came from would not stand up to turning. I have more like it and a lot that is even softer. I am trying to pick out a few good ones to dry. is there a test I can do, like ability to hold a nail or screw?

There’s a fine line between spalting and decay. My personal test is if it dents easily with my thumbnail it’s too far gone and I usually throw it out.

In some rare cases I may use wood with soft sections if the spalted colors and black zone lines sre spectacular. In this case I stabilize/harden the soft areas with thin CA glue. This sometimes takes a LOT of glue and many reapplications as the wood soaks up the glue, as well as when turning exposes unhardened areas. There are other methods, such as with resins.

If using CA there are a couple of cautions. One, wear goggles and apply in a well ventilated area since the CA fumes are horrible on the eyes. Second, in some cases an exothermic reaction can create way too much heat. Best to apply slowly and let that harden before adding more. I usually use a capillary tip on the CA bottle to control the amount and placement. I never use CA accelerator since that can result in a real mess.

JKJ

[David Walser]

Maurice -- Wood like this is why god invented Cactus Juice. In case you're not familiar with it, it is a very thin resin that, once cured, stabilizes punky wood. Once stabilized, the wood is hard and can be worked with typical woodworking tools. Stabilized wood accepts details very well. So, unlike with most highly stabilized pieces that are sanded to final shape, you can make sharp, crisp, details -- even chase threads.

If you're going to stabilize it, it really doesn't matter how rotten the wood is. What matters is how attractive the wood might be. Of course, that's a matter of personal opinion. I really like the your lamp base. The wood you used, with all that spalting, is spectacular. However, some don't like that much spalting -- just as some find highly figured woods too busy. If you have more wood like that, I'd be stabilizing as much of it as I could.

If you want to learn about stabilizing, go here: https://turntex.com/product/cactus-juice-resin-and-dyes. Lots of places sell Cactus Juice and similar resins, but Curtis Seebeck has done more to bring this technology to woodturners than anyone else. (I'm a happy customer, but have other relationship with TurnTex.)

Of course, not everyone wants to stabilize wood. That's fine, too. In that case, if the wood is too soft to hold a screw, I wouldn't turn it. The risk of it coming off the lathe would be, for me, too great.

[Maurice Mcmurry]

Thanks David and John! that is excellent Information! Is American Elm considered desirable for turning?

[Barry McFadden]

Whenever I'm turning spalted wood that has soft sections I use this https://www.homehardware.ca/en/16oz-pc-petrifier-wood-hardener/p/1626182 to harden it and it turns well.....

[John K Jordan]

… Is American Elm considered desirable for turning?

Some don’t like the smell when turned green. I prefer to turn dry wood and dry elm doesn’t have that problem.

Elm, like many domestic hardwoods, is good for all kinds of turning. It turns cleanly with sharp tools; takes finish well.

It’s strongly ring porous with large earlywood pores and very distinctive wavy bands of latewood pores, easily visible in turnings. Elm has a coarse texture compared to woods like cherry and holly. The interlocked grain makes it tough and less likely to split.

American elm does have a high T/R ratio so it may warp more as it dries and move a more with the seasons than some other species such as black walnut.

JKJ

[Richard Coers]

I would not put elm in the category of spending hundreds of dollars to set up a stabilizing system and adding the cost of the material itself. $90 a gallon is too pricey for me. You also need an old oven to cure the resin if you intend to do turning blanks for bowls.