Microwave a green turned bowl dry...

[Tom Henry]

Did anyone try this and is so how did it turn out...it just doesn't sound safe or sanitary.

Microwave Drying Method:
The microwave drying method is not widely used. It is a great way to get instant results from a piece of green wood, but does not produce consistent results. To microwave dry a piece of wood, simply place it in a microwave, and heat it on a medium setting for approximately 45 seconds to 1 minute. Remove the piece (careful, it'll be hot!), weigh it, and write down the measurement. Once it has cooled, place it in the microwave again and repeat the above steps. Continue doing this until the weight of the blank stabilizes. At this point, the blank has stopped losing moisture into the atmosphere, and is ready to be finished! :eek:

[Brian Effinger]

I've never tried it, but I read somewhere to put it in a paper bag when you do it.

Oh, and no matter what, don't use the microwave in the kitchen.

[Jim Kountz]

I tried several different methods of this and none worked for me. I cant remember where I got the instructions but it was somewhere else on the net. Lots of cracks.

[John Fricke]

Oh, and no matter what, don't use the microwave in the kitchen.

Yea.....I think most that do this use a dedicated micro for the task. Might be ok for something you are in a hurry to get finished but I think it requires a lot of babysitting for desired results.

[Bernie Weishapl]

I tried it a couple of times and didn't like it. Don't use momma's microwave either.

[Ken Fitzgerald]

I nuked a green cherry goblet and it turned out okay.

A bowl?......I'd want a dedicated microwave.

[Mark Burge]

When I tried it on a very small bowl, just to see what would happen, I got a burned spot pretty easily, but it was dry for sure.
- Mark

[David Walser]

I won't steal Bill's thunder. I will say that he did use the microwave in the kitchen -- once -- and the method is now referred to in his house as "The Method That Will Never Be Used Again", or some such.

It's a funny story and you should attend one of his demos if only to get the chance to hear the story.

[Jason Hallowell]

I've tried it several times, with mixed results. From what I can tell, it works best when done slowly, and on woods that have above average stability to begin with. Last year I milled up a bunch of pen blanks from green wood (mostly mesquite and olive), and had great results drying them in the microwave.

Oh, and the above comments about not using the microwave in the kitchen are all true.

[Scott Conners]

I've done it when I needed to dry blanks for tool handles and my pecan was very wet. It works well, but still takes quite a bit of time. The blanks will get quite warm, and take a surprisingly long time to cool down. Too much heat at once and you'll start to produce cracks. I ended up doing longish (10-30 min) at 10% power, which makes the microwave cycle on for ~25 secs and off for a few minutes. I did do it in the kitchen microwave, and had no ill effects. I imagine with cooling time a decent size bowl blank woudl still take a number of hours with all the cycles it would take to get fully dry. The water can only migrate out of the wood so quickly, even when you're steaming it out like a microwave does.
I did have some small shrinkage a few days later when I didn't take enough time and do enough cycles, even though the weight wasn't really changing. I suggest still letting a microwaved blank rest a day or three before turning, but it is a totally viable technique when you need to dry something fast.

[Dick Sowa]

I've microwaved maybe a dozen bowls, and it can be a very effective way to dry green wood. But like others have said, it requires you to be there, and monitor the progress all day long. I have done it with maple, box elder, and walnut...and they all worked well. But they are also pretty stable woods to start with.

I rough turned the bowl blank so the wall thickness is about 10% of the diameter...just like you would if it were going to air dry.

I used the DEFROST cycle for 2 mins, then let it cool in the microwave for 30 mins. It releases a lot of steam, so I had to wipe down the inside of the microwave occasionally. I repeated the 2 minutes on DEFROST cycle 6-12 more times, rotating it with each cycle (I don't have a turntable microwave). The bowl was never hot...but did get warm to the touch.

This first batch of microwave cycles took a whole day, and by the end of the day it was almost ready.

The next day, I continued the DEFROST cycles, but got a bit more aggressive and increased the duration to 3-4 minutes. After about half a day, there was very little change in weight between cycles, and the inside of the microwave wasn't steaming up like it was the day before.

I then remove the bowl from the microwave and set it aside in the shop to stabilize for a couple weeks before turning.

Once caution though. If you don't get it nearly dry the first day, and let it sit in the microwave overnight, the warmth and humidity could cause the wood to mold. I lost a couple bowls that way.

Here's a pic of one of the successes:
http://www.digitalwinners.com/pics/woodwork/P1040296a.jpg

[Mike Gager]

i read somewhere about putting the green wood in a regular oven to dry it. not sure if that works or not though

[Bruce Shiverdecker]

I use the Micro method a lot.

My formula is a little different. I use 20% for 2 minutes - let cool - repeat till it is no longer hot when it comes out, it is dry. Do not nuke it more than 5 times in 24 hours, then you won't get stress problems.

Then I let it sit for a while to
stabilize

Bruce

[Dick Strauss]

Is there a rule of thumb for drying different sized pieces in the micro? I would assume that a 4" dia bowl 0.4" thick should be dried at a lower power setting than a 10"/1" thick bowl...???