Wood Stabilizing #1 Equipment and First Batch
I've got some spalted elm left over from building my low bench plus some soft maple and other woods that are a little soft and punky. But they're very pretty, so I decided I'd give wood stabilizing a try.
I ordered a vacuum chamber and pump on eBay, plus a gallon of Cactus Juice from Turntex. Once everything arrived, I assembled the hose and tested the vacuum chamber. The pump pulled a vacuum quickly, and the chamber held it reasonably well, so I was good to go on that front.
I cut up a bunch of knife-scale-sized pieces of wood. Made two each of:
- soft maple
- hard maple
I set all the wood in my shop toaster oven and was going to set it for 12 hours at 220F, but the timer on that only goes to 2 hours. So I ended up using the toaster oven in the kitchen, which has a 10 hour timer. Didn't leave a bad smell or anything, and my toast tasted fine this morning, but I'll probably be upgrading the toaster oven in the shop soon.
After getting the wood dry, I put it into a two gallon ziploc bag to cool. According to Curtis' instructions drying the wood first is important, and then cooling it before putting it in the Cactus Juice is critical so you don't prematurely cure the juice.
Once it had cooled, I put the wood into the vacuum chamber and put a chunk of ¼” steel plate on top of it. That wasn't quite heavy enough to keep the wood from floating, so I threw some lead into a spare plastic tub and put that on top of the plate to weight it down.
Then I poured in about a half-gallon of juice, which gave me about a half-inch over the top of the wood (probably should've used a little more), put the lid on the chamber and started to pull vacuum. It got to -27 inches pretty quickly (15-20 minutes), but then there was a continual small stream of bubbles from the wood, so I left it chugging.
After 2.5 hours, the bubbles had finally stopped, so I released the vacuum and left the wood to soak while I wrote this. It's supposed to soak for 2-3 times as long as it took to get the bubbles to stop, so I'll just leave it overnight.
The next entry will covert wrapping the wood (to keep it from sticking together) and baked the wood to set the resin.
When I first wrote this, there were a number of questions people asked. Here are answers to some of them.
- Regarding vacuum chambers – many of the cheapest vacuum chambers are not rated for stabilizing wood. This is because the resin will attack many of the cheaper plastics. According to Curtis at TurnTex, PVC is ok for the lid.
- The wood needs to be dry before you stabilize it. Curtis recommends baking it for 24 hours at 220F, then sealing it in a plastic bag while still hot to prevent it from picking up moisture from the air. The timer on my toaster oven only goes to 10 hours, and I haven't had a problem with 10 hours at 220F, as long as I haven't tried very large pieces of wood (such as bowl blanks).
- Stabilized wood has a few benefits. The open pores in the wood have been filled with the acrylic resin, which is then set by heat. This means that the wood will be heavier and harder. In the case of ring-porous woods, the variation in hardness between early-wood and late-wood will be lessened by the stabilization, making the wood more uniform and easier to carve. Finally, the wood will move much less due to moisture changes.
- Yes, you can dye the wood while stabilizing it. I'll be adding a section on that later. Without dye, the stabilizing resin will darken the wood somewhat, similar to coating it in tung oil or light shellac.