Burl with a few PPB

[John Kananis]

It depends on mass and size of the blank and the wattage of the microwave. The larger the blank, the longer you'll put it in for. You are probably pretty safe doing 2-3 minute cycles until it is pouring of steam. Wait 20-30 minutes, flip it, and repeat.

Ok, sounds good. It's 12x14x6 or so. 2.5 minutes every 20-30 minutes sounds like a plan. How many times should I do this before I risk the blank? Figure about 1k watts, which is average.

 

[Michael Nathal]

I'm curious how you determined that that was sufficient to kill dormant eggs in the wood?

Yes, you are right, it's not absolute proof. . I only observed dead bugs. And no re-occurrence of the sawdust piles.

 

[Paul Paukstelis]

Ok, sounds good. It's 12x14x6 or so. 2.5 minutes every 20-30 minutes sounds like a plan. How many times should I do this before I risk the blank? Figure about 1k watts, which is average.

That would probably be fine. Personally, I would probably start with 4-5 minutes once, then do 2 minutes every 10 minutes or so. The main thing you want to avoid is what you would run into in a normal oven, which is you have uneven heating on the interior and exterior. That's what is going to lead to cracking/checking. I would leave it in the microwave between cycles, as it will insulate and retain some heat so the exterior doesn't start cooling too fast.

 

[John Kananis]

Sounds like good advice, thank you, Paul.

That would probably be fine. Personally, I would probably start with 4-5 minutes once, then do 2 minutes every 10 minutes or so. The main thing you want to avoid is what you would run into in a normal oven, which is you have uneven heating on the interior and exterior. That's what is going to lead to cracking/checking. I would leave it in the microwave between cycles, as it will insulate and retain some heat so the exterior doesn't start cooling too fast.

 

[Alan Weinberg]

Be careful—a blank can catch on fire in a microwave.

After my wife banned my use of the kitchen micro, I bought a good used one on Amazon for $80. Works well—I dry roughed out pieces that I’m impatient to finish as well as sometimes once turned wet pieces.

 

[John Kananis]

I didn't consider that the blank can catch fire. Extenuating circumstances?

 

[Paul Paukstelis]

I didn't consider that the black can catch fire. Extenuating circumstances?

Very unlikely to happen to a large, unturned wet blank. It will only catch fire in cases where it has fully dried. If you are too aggressive with drying bowls after the first turning they will char. I always feel it is better to do shorter cycles more often than trying to do long cycles (one of the reasons I developed the automated microwave system) because you get better heat distribution throughout. When you turn the power level down on a microwave, it doesn't actually adjust the flux (at least not household microwaves) it just adjusts the duty cycle. Same idea.

 

[John Kananis]

Thanks again...I'm now wondering how the microwave process will play with anchorseal. Does it make a mess (if you know)?

Very unlikely to happen to a large, unturned wet blank. It will only catch fire in cases where it has fully dried. If you are too aggressive with drying bowls after the first turning they will char. I always feel it is better to do shorter cycles more often than trying to do long cycles (one of the reasons I developed the automated microwave system) because you get better heat distribution throughout. When you turn the power level down on a microwave, it doesn't actually adjust the flux (at least not household microwaves) it just adjusts the duty cycle. Same idea.

 

[Paul Paukstelis]

Thanks again...I'm now wondering how the microwave process will play with anchorseal. Does it make a mess (if you know)?

It will soften and the steam that starts coming out of the endgrain will cause it to ball up or come off. Just reapply, or better yet just do your first turning after treatment.

 

[Richard Coers]

It depends on mass and size of the blank and the wattage of the microwave.

Don't forget density.

 

[Alan Weinberg]

I didn't consider that the blank can catch fire. Extenuating circumstances?

No. Left in too long.

 

[Paul Paukstelis]

Don't forget density.

Its already there (if you are willing to interpret size as volume).