Microwave frustrations!!

[Lou Tribble]

Any suggestions on microwave drying turnings (power levels, time, sources of info, etc.). My results are inconsistent, but I remain determined to make this work. Thanks!!! Lou

 

[arbud]

Slow down

Lou, I have found that I get the best results by microwaving at full power for no more than 1 min. I then check the moisture content w/my handy, dandy, moisture meter and then do another min., etc. When I get a reading of 10-12% at several points I quit, put the piece in a plastic garbage bag until it's cool, remove the piece, and either finish it or store it.

This isn't a precise thing, you'll have to play with the process.

 

[bonsaipeter]

Microwave Drying

This is one of those questions that if you ask two turners, you will get at least three opinions.

I have found what works best and SAFEST for me on roughed out bowl blanks is the following:

1) Weigh and record wet piece to get a baseline of how much water is in it.

2) Heat in microwave oven for 1 min. at full power.

3) Remove from oven and allow to cool several hours to room temperature.
(If you immediately reheat the piece repeatedly, the internal stream pressure may get high enough to cause the piece to split. Additionally, a "dry spot," particularly the corners or edges may get hot enough to catch on fire. Wives get real funny about having burning pieces of wood in "their" microwave oven! Been there, done that, ask my wife).

4) When completely cooled, reweigh the piece. The difference in weight from the initial weight represents the amount of water lost.

5) Repeat Steps 2 - 4 until the loss in weight from the previous weighing gets to be about 1%. Careful, you can overdry the piece. I get in about 3-4 cycles per day and found that 7-10 cycles will usually do the job over the course of 2-3 days.

6) Let the piece sit for a day or two before turning to let the internal stresses relieve themselves.

Don't be surprised if a wet piece looses 20 -40% of its initial weight as water.

Give it a try. Peter