food dehydrater for small wood pieces

[yukon cornelius]

ive got some projects im wanting to make but all my lumber is pretty green. I was wondering if I could cut out my pieces and put them in a dehydrator to get them to dry out. my dehydrator is adjustable from 95 all the way up to 160 degrees. it has a fan for air circulation. any thoughts

[21incher]

Interesting idea. I think it will most likely dry to fast and crack but if you cycle it on and off to let the wood equalize it might work. Why not try it with some scrap first and let us know how it works.

[Dodgy Loner]

If they're small pieces, a microwave works pretty well. Put them in for no more than a minute, then let them cool a few minutes, then heat them again. It will dry the wood very quickly.

[Farmerjw]

If they're small pieces, a microwave works pretty well. Put them in for no more than a minute, then let them cool a few minutes, then heat them again. It will dry the wood very quickly.

If you weigh them, when they quit losing weight they are dry.

[yukon cornelius]

a microwave is an awesome idea! im gonna cook me some wood! I also never considered the weighing. that's why I came here! thanks! I will post some results!

[Busy Beaver Lumber]

I bought plans for a dehumidifier based kiln a few years back and this is going to be the year I build it. You can make it pretty much any size you want that is larger than the size of the dehumidifier you use. Pretty simple concept. Flood light type bulb for aux heating, dehumidifier to extract water from hot moist air and send it outside the kiln and a small circulator fan. Using a used dehumidifier, i am thinking you could build one for a little over $100.

One word of caution about using a microwave to dry wood. I know of a fellow that tried that with almost deadly consequences. He had a block of somewhat moist wood in the microwave and was drying it. Microwaves cook from the inside out. The moisture inside the block heated and expanded faster than it could vent from the wood and the block literally exploded and punched a hole through the microwave door. Had he been in line with the door or looking in, he would have been seriously injured. I am sure we have all had some food explode in the microwave of a sealed food package blow in there. Now picture that on a much larger scale and with a lot more potential energy behind it.

One alternative I would offer is the small toaster ovens. When I go to dye stabilize wood, we want the moisture content under 10%. With wood wetter than that, a 24 hr bake in the toaster oven at 150 to 200F accomplishes that task nicely and safely.

I have always been kind of leery of using household appliances that are use to prepare my food for any other reason for fear of contaminating them. If I were to use a food dehydrator, toaster oven, or microwave for wood working, then it would not be used for food prep again.

[beenthere]

I have always been kind of leery of using household appliances that are use to prepare my food for any other reason for fear of contaminating them. If I were to use a food dehydrator, toaster oven, or microwave for wood working, then it would not be used for food prep again.

??
Not sure I follow that reasoning, or how wood would contaminate any of those mentioned? 

[Busy Beaver Lumber]

beenthere

For what is is worth and in support of my opinion only:

Maybe i think things like this too deeply, but I work with precision optics on the weather satellites that capture the weather images you see every day. Optics contamination is a big issue and avoiding that contamination takes major precautions.

All materials do what they call outgas, that is they give off molecular particles when they are heated or when the dry or cure. Most times we notice such events in the form of smoke like particles or just plain odors, but it occurs in almost every solid that goes from one temp to another. Shed molecules then land on other surfaces. One way we accelerate this molecular particle shedding is to heat the item up. As something is heated it outgasses at a greater rate, kind of like accelerating the drying of paint with a blow dryer. As the paint reaches it final solid state of being cured, it sheds less particles and the odor becomes less detectable.

Some woods contain high levels of acid that are not good for components not rated for exposure to acid. One of the complaints on the dehumidifier based kilns is that acids from the wood condense on the coils and cause premature failure. Even darien, the kiln designer acknowledges that as happening, but then logically goes on to say that by the time it KO's his dehumidifier, he is well ahead of what it would cost him to have his wood kiln dried by someone else. If wood acids can do that to a dehumidifier coil, I don't think I want them in an oven used to cook my food.

Also bear in mind that spalting in wood is caused by bacteria. And I have been surprised more than once by finding a dead critter, be it worm type of beetle in nature, at the bottom of my toaster oven that I had no idea was inside one of the pieces i put in there.

Other woods contain oils that can cause rashes on the skin of people sensitive to them like cocabola. Would not want to get that type of oil in the oven my food was cooked in.

[Dodgy Loner]

Maybe i think things like this too deeply...

Yep, you do. I use the microwave to dry eating and cooking utensils that I carve green. If I was worried about them poisoning my microwave, then I'd have bigger issues at hand.

[Ocklawahaboy]

If you've missed any tramp metal in those little pieces - no matter how small - your microwave is likely to start the wood on fire.

[Dodgy Loner]

My tea bags have staples in them and I've never caught my tea on fire. But thanks for the warning.

[fat olde elf]

I have microwaved 100's of 1/4" Christmas ornaments ERC.  This is after carving and getting ready to varnish.  one minute cycles, usually 3 times. Poly varnish gums up if the cedar is too fresh.  Same routine for plaques of 1x 4 as long as will fit in oven. No problems... I do this when my wife is sleeping.........The swedes are trying to make larger microwave kilns. Den S. says there are still problems. Stay tuned....

[Ianab]

Don't use your wife's microwave. Even if nothing serious goes wrong, it will still smell of wood afterwards.

Either buy the wife a shiny new one, and take the old one to the shed, or pick up a cheapy at a 2nd hand shop. Then if it gets smelly, or blows up, no big deal.

But drying small items is practical, you just need to adjust the power and time so as not to set fire to them.  :D

Ian

[Ljohnsaw]

I had to replace my old (10+ years) microwave.  The new one is a truly variable power (inverter).  The cooking box is bigger because it doesn't have the huge transformer on the side.  It was surprisingly cheap, too - I think it was half the price of the original, if not cheaper.  I think an inverter microwave would be the ticket - adjustable power setting, large oven space and efficient.

[Dodgy Loner]

Don't use your wife's microwave. Even if nothing serious goes wrong, it will still smell of wood afterwards.

You folks come up with all sorts of problems that I've never had. I've used a microwave (same one that heat my food with) for about 10 years with nary an issue. Microwaves are cheap, though, so it wouldn't hurt to have one in the shop.

[yukon cornelius]

im not scared to try some in the nuker wave. im also gong to try the dehydrator as soon as I get my pieces cut out. I will post results

[Ianab]

You folks come up with all sorts of problems that I've never had. I've used a microwave (same one that heat my food with) for about 10 years with nary an issue. Microwaves are cheap, though, so it wouldn't hurt to have one in the shop.

Lets just say Lil is very sensitive to the smell of Port Orford Cedar  :D

[Dodgy Loner]

That makes sense, Ian. I have never nuked anything as aromatic as Port Orford Cedar. Mostly just thing like cherry, walnut, and hickory. It is great for drying out hickory handles (unfinished, of course) bone dry before fitting them. When the handles swell back up to the ambient humidity, they swell so tight they never come loose.

[Ocklawahaboy]

I've seen quite a few metal things catch fire in a nuke.  One was as simple as some foil lettering on a paper plate.  Caught the plate on fire.  One a twist tie left on a baggy started sparking and shattered the glass tray in the bottom. 

[jueston]

once i was drying a piece of wood in the microwave, which i have done several times, when i got distracted by something shiny. i left if in too long and it started to smoke.

i removed the piece and threw it away since it had some dark black spots.

2 hours later my girlfriend got home, took a deep breath, and asked if i was barbecuing something amazing?

i guess some of that smell soaked into my jacket too, because the next day someone asked if i had been barbecuing....

i then cleaned the microwave and my jacket, and life is back to normal....

[Ocklawahaboy]

once i was drying a piece of wood in the microwave, which i have done several times, when i got distracted by something shiny. i left if in too long and it started to smoke.

i removed the piece and threw it away since it had some dark black spots.

2 hours later my girlfriend got home, took a deep breath, and asked if i was barbecuing something amazing?

i guess some of that smell soaked into my jacket too, because the next day someone asked if i had been barbecuing....

i then cleaned the microwave and my jacket, and life is back to normal....

So are you saying that next time I throw some left over ribs in the microwave I should throw a little chunk of pecan in for that smokey flavor?

[terrifictimbersllc]

Can someone explain why is there a fuss about putting metal in a microwave, when the merry go round rack the plate sits on is made out of metal?

[Ocklawahaboy]

Can someone explain why is there a fuss about putting metal in a microwave, when the merry go round rack the plate sits on is made out of metal?

Don't know the physics of it but I have seen the results.

[Busy Beaver Lumber]

As per Daven Hiskey

When microwaves are reflected instead of being absorbed, it can potentially create a sufficient charge density that the electrical potential in the metal object exceeds the dielectric breakdown of air. When this happens, it will result in arcing inside your microwave, from that metal to another electrical conductor with lower potential (often the wall of the microwave). In extreme cases, these electrical sparks can end up burning small holes in the metal wall. The sparks can also end up burning out the magnetron in your microwave oven or, in modern microwaves, can generate a surge that ends up damaging sensitive microelectronics, possibly killing your microwave or making it unsafe to use.

Another way putting metal in the microwave can kill the magnetron is when enough of the generated microwaves don't get absorbed, which might happen if the food is wrapped in aluminum foil or mostly enclosed in a metal container. If the energy isn't absorbed, it has nowhere to go but back to the magnetron to damage it—which, again, can render your microwave useless.

[terrifictimbersllc]

As per Daven Hiskey

When microwaves are reflected instead of being absorbed, it can potentially create a sufficient charge density that the electrical potential in the metal object exceeds the dielectric breakdown of air. When this happens, it will result in arcing inside your microwave, from that metal to another electrical conductor with lower potential (often the wall of the microwave). In extreme cases, these electrical sparks can end up burning small holes in the metal wall. The sparks can also end up burning out the magnetron in your microwave oven or, in modern microwaves, can generate a surge that ends up damaging sensitive microelectronics, possibly killing your microwave or making it unsafe to use.

Another way putting metal in the microwave can kill the magnetron is when enough of the generated microwaves don't get absorbed, which might happen if the food is wrapped in aluminum foil or mostly enclosed in a metal container. If the energy isn't absorbed, it has nowhere to go but back to the magnetron to damage it—which, again, can render your microwave useless.

Wow you're fast BB.   While I was still reading.  http://www.todayifoundout.com/index.php/2010/08/why-you-generally-shouldnt-put-metals-in-the-microwave/
Still don't understand it but better not to put metal in the microwave.