• Congratulations to Alex Bradley winner of the December 2024 Turning Challenge (click here for details)
  • Conversations are now Direct Messages (click here for details)
  • Congratulations to Gabriel Hoff for "Spalted Beech Round Bottom Box" being selected as Turning of the Week for January 6, 2024 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Micro Wave Drying

B

bbrussell

Joined
Jan 6, 2005
Messages
43
Likes
1
I have had a discussion with a club member concernig using the nuker to dry rough turned bowls. I use the defrost function in short bursts, weighing the piece until it no longer loses weight. He uses full power for several minuites and watches for smoke. We both claim good results. I am wondering what regemine others use, always looking for a better way.
 
I'm with you on short burst (low power) and longer time, though others do work differently. Since ignition originates in the driest, best-insulated place in the piece, the longer and lower allows me a bit more leeway in shape and thickness. I have had good luck placing the piece in a perforated plastic bag and going high power, but I was interested in plasticising the wood for some deformation experiments then, and didn't nuke to ignition.
 
I also prefer a short burst or a longer stretch of low (10-20%) power. I often put the piece in a paper bag to minimize surface checking, even though the checks normally close again when the piece is completely dry.

I've used long high power zaps on wet blanks to arrest the spalting and kill the bugs. The process is fairly "aromatic" so I move the microwave outside. The chunks were fairly large and I'd zap them for a couple of minutes until they were steaming good, then rotate another chunk into the microwave and let the hot chunk cool for a while before zapping it again.

I did get a little too zealous with a nice cherry blank once. Smoke suddenly started pouring out. And the microwave was in the kitchen. Mad rush for the door. 😱
 
Brian Hahn said:
I also prefer a short burst or a longer stretch of low (10-20%) power. I often put the piece in a paper bag to minimize surface checking, even though the checks normally close again when the piece is completely dry.
Click to expand...

Worth mentioning here that the standard "low power" settings on modern microwaves are really just full power with variable length interruptions. Check your manual, or listen to your fan slow and then speed up as the magnetron powers off to confirm this.
 
Power cycling

I like to take advantage of the power cycling of the microwave, especially when the wood is still really wet. I'll warm up the wood with a full power burst, then switch to 30 minutes of 5-10% power. (My old shop microwave is adjustable in 1% increments.) The minimum power on cycle for that microwave seems to be about 7 seconds. So the piece gets zapped for 7 seconds, then it's just the fan and light running for a minute or two. Helps remove the moisture, but more slowly than if I took the wood out to cool. And I don't have to futz with it. :cool2:
 
You Want Fries With That?

Just amazes me that folks just can't seem to let a little piece of wood dry out naturally. "Nope. I turned this Bad Boy dead wet this morning and I'll have the final coat of finish on him and ready for, um, ah, well whatever, this evening!" Jeez, guys, how much, between hot plates, microwaves, kiln heaters, and a plethora of chemicals, do you all have to spend producing that piece?

LDD, freeze-dried, nuked, boiled, baked, deep-fried, what is so Gawd-awful vital that mandates not letting the poor bowl dry at its own natural pace? Is there some Rule somewhere that I missed that says any particular piece must be finished within some number of hours after the damn tree hits the ground?

No, this ain't rhetorical. I truly don't see what all the rush is about, but I do see a whole lot of effort being put into shortcutting a process that's gonna happen in a month or two anyway.

Life may be short, but not that short.

Mark

ps: bb, I'm not picking on you or criticising your posting your question in the least. I just think it's worthwhile to look at the basic premise you raise. 😉
 
Last edited:
With fries and a malt to go, and HURRY!

Mark, you raise a very valid point.

While I've let some rough out bowls dry for a year or two, there are two situations where I'll hurry the process:
  • Deadline: the piece needs to be done soon, usually it's a present or an entry in our club's monthly challenge; and
  • Exploration: when I'm exploring a shape or form. Sometimes I'll turn to final shape when it's green and not worry about wood movement. But other times I'd like to have the shape be more "permanent". Letting the piece dry naturally puts too much distance between the original concept and the final turning.
 
Last edited:
Thanks to all of you for your input. Mark, no offense taken, but there are many reasons not to wait for nature: need for the finished product now is the one that often plaques me, impatirce is another, and some of us are so old that if we wait for nature, we may not see the results.
 
For some of us there's satisfaction in letting a bowl dry au naturale. For others, caught up in the "instant" society we live in, we see the lathe as allowing us to produce a finished piece in one session and look for ways to faster bowls.

If you're the former, it's probably annoying reading posts about LDD, DNA, boiling, microwaving, etc.. We're always on a quest, it seems, for faster and better.

Different strokes....

Life is frail. At my age, I just want to be around when the bowl dries.

Jack Savona
 
gran said:
Has anyone tried combining the alchol soak with microwave drying? Too much of a good thing perhaps?
Click to expand...

Foolishness aside, no difference between alcohol and water as far as the microwave is concerned. Just some molecules to agitate. Of course ethanol goes to vapor several degrees lower than water, which means the initial stages would be a still.

As liquid evaporates, it maintains temperature, which is why boiling something will never get it above 100, unless you're below sea level, even though the flame below is considerably hotter.
 
I'm with Mark Mandell on this one. And I say that even though I first got into turning with the mistaken belief that you get instant results (as in plowing snow). What I've since learned is that life is far too short to worry about hurrying up any process. The more artificiality infused into wood - or life - the shorter the journey is. And the journey is much more interesting than the destination.

Why do you think they make ketchup take forever.

It's worth the wait.
 
Of course, there are some instant satisfaction products available to occupy your time while the longer-term cure. Ornaments, board turnings of the single or glue-lam variety come to mind. Then there are the relatively short-term types like warp and go. Lopped a piece off of the end of a cherry log yesterday to make a couple of bark-up pieces to replace some that sold. First went nicely, sitting downstairs drying right now. Finish in a week, since cherry gets a bit muddy if it sits unfinished too long. Hardly instantaneous, but it's the creative part that I like - the rest is just sanding and wiping. Other side had a radial check that I hadn't noticed initially where the mule or harvester had peeled the bark back, allowing some drying of the sapwood. Turned that bark down, but it'll be ready in a month anyway, as it's cut to about 5/8.

Haven't you noticed that they have upside-down squeeze-dispensing ketchup containers now? Instantly splatters it all over the plate and you.
 
You must log in or register to reply here.
Back
Top