Microwave drying?

[Eriksen]

I have cut some wet spalted beech into knife handle scale sizes and need to know how to dry these in microwave. Any here with experienses?

 

[A.McPherson]

Don't dry it in the microwave. It won't dry evenly, and will split and crack and warp.

If you've already cut it thin, it won't take much time to dry naturally, maybe a couple weeks.

 

[john april]

i try to keep wood a year or two before using it so the chances of warping, twisting and shrinking are minimal once its on the knife. a quicker method would be to send it to K&G for stabilizing. it will be a higher quality scale as well. impervious to moisture retention.

 

[Ken H>]

I have cut some wet spalted beech into knife handle scale sizes and need to know how to dry these in microwave. Any here with experienses?

I suspect you're planning to home stabilize the spalted wood? OR, do you plan to send it to K&G for stabilizing? Spalted wood really does NEED stabilizing prior to use.

If the wood is truly "wet", I'd let it dry naturally for a few weeks. When ready to do your stabilizing then you could dry in oven around 200°F for a few hours until it's really dry, then move directly to the vacuum chamber. I'm told you can put dried wood in a ziplock baggie for "up to" 24 hours storage before putting in vacuum chamber for stabilizing. For stabilizing wood really needs to be dry. Ideally lower than most moisture meters will measure.

 

[weo]

Any here with experienses?

Yes, and I'll agree with what's been said above in that there's much more risk when trying to speed up the process in this way. When I used to have my own property and trees to harvest, I experimented with microwaving pieces. IIRC, about 90% of the pieces warped and split. I tried multiple 30-60 second sessions to try to minimize this, but wasn't able to control it. Another thing I noticed was that about 1/2 the pieces showed burning/scorching on the inside of the pieces when they were cut up.

 

[Eriksen]

I suspect you're planning to home stabilize the spalted wood? OR, do you plan to send it to K&G for stabilizing? Spalted wood really does NEED stabilizing prior to use.

If the wood is truly "wet", I'd let it dry naturally for a few weeks. When ready to do your stabilizing then you could dry in oven around 200°F for a few hours until it's really dry, then move directly to the vacuum chamber. I'm told you can put dried wood in a ziplock baggie for "up to" 24 hours storage before putting in vacuum chamber for stabilizing. For stabilizing wood really needs to be dry. Ideally lower than most moisture meters will measure.

I do the stabilizing process myself at home. Maybe it was wrong to cut the spalted slab into scales before the drying process? I´ve heard from others that pieces will crack if they just air dry because the outer sides will dry faster than the inside and therefore the microwave drying will be better because the whole piece is warmed up evenly.

 

[FredyCro]

I reseaeched this a lot as well, a lot of wood turners use this method for drying greenwood, but the preferred method for quick drying is sticking it into a can of desiccants, preferably the reusable sort with moisture indicator. I am planning to try this with my next batch for the stabilizing, but who knows when I will get to actually doing it..

 

[fitzo]

Rice makes an excellent dessicant. Dry in oven for re-use.

 

[Ken H>]

Cutting wood into blocks is by far the best - thin scales are so much worse to warp. It's the fast drying that causes wood to warp. You want it to dry slow to prevent (help prevent) warping, and put a wax or paint over the end grains to slow the drying process out to help prevent cracks.

Drying the wood in a oven is for the final drying process AFTER the wood is fairly dry (below 10% or so) just before putting in vacuum chamber for stabilizing.

 

[Randydb]

I have been collecting wood and cutting blocks for a few years now. I find interesting pieces of wood and toss them under my porch to dry for a year or more. Then I cut them into blocks and get them stabilized at K&G. Most pieces I find I cut into 2 foot lengths before being left under the porch. If it is a piece that I think is really going to have some spectacular look I paint the cut ends or wax them. Generally I have so much there that the odd one cracking doesn't really bug me. One thing I have found is that spalted wood seems less likely to crack on me... but this is just my anecdotal observation...no scientific tests.
I have a moisture meter and I check the moisture in a piece before I cut it into blocks. Living north of the pacific north west in a temperate rainforest, dry is about 9%-12% moisture content. K&G want the pieces below 9%. Drying the blocks the last few % isnt bad...I stick them near a heater vent in my house until I get to around 8%. Get the odd crack but not often.
Personally, I figure if you just build up a stash under the porch, you always have lots that are dry and ready to turn into blocks. No need to rush it then.