When roughing bowls, some pieces of wood are more susceptible to instant checking than others, and you really have no clue which ones will, and which ones won't. There are two things that are elements that effect this kind of checking.......heat and exposure to the ambient environment.
The act of turning, itself is going to cause heat, but it can be minimized by the sharpness of the tools, and taking smaller cuts. The spinning motion of the wood on the lathe is, in itself, a cooling factor.....so, taking smaller cuts, and taking your time, contributes to reduce the amount of heat generated, and the time/ability of the cooling factors to work.
I have used anchorseal on the exterior of a bowl while roughing out the interior......and, I don't think this is excessive to think it's a little more able to prevent checking than a plastic bag. It only takes a matter of 20-30 minutes for the anchorseal to set-up, and can be turned on the lathe......without any mess. I usually don't do this, unless I see signs that checking is initiating. Most wet bowl blanks aren't as likely to check......but, there is that occasional example that will, and usually you can tell by the surface appearance........sometimes not.
As I see it, anchorseal is the better choice, because it seals directly to the surface, and seeps into any voids and existing cracks......while plastic bags, or wrap will necessarily have gaps and allow small air pockets between the wood and plastic. The advantage to plastic wrap, is it's instantaneous, while the anchorseal requires some set-up time.......
ko
