Anchorseal and Microwaving

[Glen Blanchard]

Sounds like an odd combination, doesn't it!!!!

I have been microwaving my bowl and vessel rough turnings on a limited basis with a fair amount of success. However, periodically I still get some very small cracks in the end grain of these pieces (which sometimes seems to disappear later). Nothing structural or catastrophic, but annoying just the same. Obviously the end grain is drying faster than the long grain. I got to wondering if placing a coat of Anchorseal on the end grain might help here during the microwaving. Anyone ever place an Anchorsealed piece in the microwave? I wonder if it would just melt. Just a crazy idea I got in my head. I have never heard anyone trying to selectively slow the end grain drying when using the microwave.

Opinions?

[John Keeton]

Glen, never tried it, but it would seem there are other options - shellac, lacquer, etc., depending on what you intend to do going forward. I would think the Anchorseal would be a mess in a microwave, but I could be wrong.

[Peter Blair]

Hi Glen. How thick are the pieces you are microwaving? I am about to start testing a microwave myself but this is the first time I have heard about the issue with cracks in the end grain. just wondering if the item could be plastic wrapped? Just in the direction of the end grain and not around the piece?

[Glen Blanchard]

Peter - The piece I am working with currently (a vessel) has walls of about 1". I only use the defrost setting on the microwave, and never heat it up to the point where it is too hot to touch. John's idea of using shellac or lacquer on the end grain may be worth testing out.

[Fred Belknap]

I microwave a piece occasionally. I do it in a plastic bag, and heat it to the point it is uncomfortable to handle. I'm pretty sure the wax would melt on the first round.

[Glen Blanchard]

Fred - The plastic bag. Is it intended to limit the moisture loss in the end grain?

[John Keeton]

Glen, I have microwaved a couple of pieces, and like Fred, I use a high setting for about a minute or so, to the point the object is a bit hot to be handling - let it cool, and again for several cycles. I haven't used the defrost cycle, but that really does about the same thing - on and off cycle at perhaps a reduced power setting.

[Glen Blanchard]

This is the protocol I have been following. The author seems to believe that the extra heat is detrimental. Of course that is one man's opinion.

http://haslip.info/woodturning/microwave.html

[Fred Belknap]

Fred - The plastic bag. Is it intended to limit the moisture loss in the end grain?

Glen I put the bowl in a pastic bag, usually a tall kitchen bag. I put it on high power for two minutes then let it cool for five minutes. There is a lot of steam and water in the plastic bag so after the five minute cool turn the bag inside out. One needs to keep track of the weight and when it stops loosing weight it is dry. While you are drying the blank stays wet on the outside. It is a time consuming job but it does work without getting any cracks. I let them sit for a day or two in the rough out stage before turning to final thickness. Sometimes they gain a little weight.