WORKBENCH Magazine April 2005, Questions & Answer Section
Q: I want to seal the ends of some green wood to prevent it from swelling, shrinking, and splitting. I’ve heard of a product called PEG that can do this. What is it, and where can I buy it?
A: Wood cracks because the fibers shrink as they dry out. The cells vary in size and orientation, so they can deform the wood as they pull against one another as they shrink.
To minimize the effects of this shrinking, you need to either seal or stabilize the wood fibers while the wood is still green. Woodturners often use a substance called Polyethylene Glycol (PEG). Rather than sealing wood, PEG works by displacing water so that the cells dry without shrinking.
PEG does have some drawbacks, though. To use it, you melt the waxy PEG in water, and then submerse the wood for several weeks. This makes the process suitable only for smaller pieces, such as turning blanks. Plus, PEG leaves a residue that limits glue and finish options.
Instead, I’d recommend a wood stabilizer called Pentacryl (Preservation-Solutions.com). It brushes on and penetrates quickly, making it suitable for both large and small pieces. And it doesn’t leave a residue, so you can use any glue and finish after the wood dries.