Microwave drying

[John Torchick]

Gary, oak makes for great firewood, giving off lots of heat.
BTW, what lake is in the background? I guess walleye and yellow perch.

 

[Gary T Egbert]

Gary, oak makes for great firewood, giving off lots of heat.
BTW, what lake is in the background? I guess walleye and yellow perch.

Yes it does and sadly I have some to burn. Lake Superior near the lighthouse along the north shore

 

[John K Jordan]

This has worked well for me except with white oak which often cracks unless I seal it too, but it does burn nice in the fireplace.

Oh no! With white oak I have success, perhaps because I usually cut smaller blanks, then seal and dry the blanks on wire shelves before turning. This, of course, takes longer but with enough blanks there are always some to choose from.




Also, most of the white oak I've used comes from the "buttress" near the ground of some of the white oaks on our property, like this one the kids are using for tree-whacking practice. These have incredible figure inside. Wonder if there is something in the soil here. The red oaks here don't do this.

I've also wondered if the burled grain/figure inhibited cracks from starting and turning into large cracks.

I've never tried rough-turning white oak.

JKJ

 

[John K Jordan]

Gary, oak makes for great firewood, giving off lots of heat.

Oak was my favorite when I used the wood-burning stove to heat the house. Good heat for the size of the firewood.

I read a government document that said all (dry) wood produced about the same amount of heat for the same weight. Just takes more of the lighter-weight species. I didn't do careful lab experiments to confirm this.

JKJ

 

[Gary T Egbert]

Oh no! With white oak I have success, perhaps because I usually cut smaller blanks, then seal and dry the blanks on wire shelves before turning. This, of course, takes longer but with enough blanks there are always some to choose from.

View attachment 87659
View attachment 87660

Also, most of the white oak I've used comes from the "buttress" near the ground of some of the white oaks on our property, like this one the kids are using for tree-whacking practice. These have incredible figure inside. Wonder if there is something in the soil here. The red oaks here don't do this.
View attachment 87661
I've also wondered if the burled grain/figure inhibited cracks from starting and turning into large cracks.

I've never tried rough-turning white oak.

JKJ

You are right John. I have turned WO from logs in my yard I let sit under plastic with the log ends sealed for over a year. I did get some very nice bowls from this wood. To be fair the last WO I turned was not ideal and probably too close to the pith. The Sawyer cutting in my neighborhood brought me a 14in by 2 foot log which is still in my garage, plus four 14 in by 7 inch disks. In my haste to take something back to the homeowner, I cut some pieces out of the disks which failed. I gave a disk which was totally sealed very well to my son who has it in his garage. It is cracking radially like crazy. Maybe the moral of the experience is never try to make something out of wet disk wood.

 

[Scott Hargrove]

I typically turn large and small bowls to a 10% wall thickness and store each in a grocery bag with dry shavings in my dry cool basement shop. I weigh the piece and write the weight and date on it someplace before storing it. I wait a couple of weeks and weigh again. If the shavings are damp I replace them. I do this every two weeks until the weight levels off. Then I leave it out in the shop and check it occasionally. Typically the leveling off takes 8-10 weeks and by the time I finish the piece it may be 12 or more weeks. I also measure the moisture initially and after it has leveled off. I usually end up under 10% on my non pin reader. This has worked well for me except with white oak which often cracks unless I seal it too, but it does burn nice in the fireplace.

Yeah, some of my pieces just look better in the fireplace.

 

[Scott Hargrove]

Oh no! With white oak I have success, perhaps because I usually cut smaller blanks, then seal and dry the blanks on wire shelves before turning. This, of course, takes longer but with enough blanks there are always some to choose from.

View attachment 87659
View attachment 87660

Also, most of the white oak I've used comes from the "buttress" near the ground of some of the white oaks on our property, like this one the kids are using for tree-whacking practice. These have incredible figure inside. Wonder if there is something in the soil here. The red oaks here don't do this.
View attachment 87661
I've also wondered if the burled grain/figure inhibited cracks from starting and turning into large cracks.

I've never tried rough-turning white oak.

JKJ

That's some pretty oak, John. Most white oak I've seen is pretty straight grained. That looks a little like the complex grain patterns we get in the live oak around here.

 

[Steve Tiedman]

One thing I wold like to be educated on about the process of drying by microwave or even with gentle heat in a light bulb refrigerator kiln.
JKJ

John, in this thread I provide two websites that should help by way of light bulb heat. Appliance bulbs and aquarium heaters (for lizzards, snakes, etc.) are your heat sources now that regular incandescent bulbs are extinct (unless you still have a stash in a closet like I found at home!).

S

Thread 'oil finish curing kiln'

Jun 15, 2024

Here's an idea for a small oil finish curing kiln. Nothing too new here, but rather than the incandescent bulb heat source of the past, he uses a reptile cage heating element screwed into a lamp socket as the heat source. He's not using this kiln to dry wet wood (you could, but his carved wood is already at equilibrium by this point), rather he uses it for curing pure penetration oils like tung and linseed. Maybe someone here will find the concept useful.
https://davidffisher.com/2024/05/04/nine-in-the-new-kiln/
Dave Fisher is a renowned carver of bowls and utensils, he creates...

• Steve Tiedman
• Replies: 4
• Forum: Woodturning Discussion Forum

• 

 

[Gary T Egbert]

I just MWed a piece of box elder which started at 40% moisture and weighted 470 grams. After 9 cycles at full power for 2 minutes per cycle the piece weighted 346 grams and measured 9-10 % moisture. The time between bakes was typically a few hours and longer seemed better. At first the piece was pretty hot requiring gloves to handle, but near the end I could handle it bare handed. After the first bake the piece sounded like bacon frying, but the smell was not as good.

 

[Scott Hargrove]

I just MWed a piece of box elder which started at 40% moisture and weighted 470 grams. After 9 cycles at full power for 2 minutes per cycle the piece weighted 346 grams and measured 9-10 % moisture. The time between bakes was typically a few hours and longer seemed better. At first the piece was pretty hot requiring gloves to handle, but near the end I could handle it bare handed. After the first bake the piece sounded like bacon frying, but the smell was not as good.

That started as a one pound piece... from my limited experience, 2 minutes was a good choice. I've never done more than 5 minutes at a time, but that's on 8"+ diameter bowl blanks. I have also noted that the pieces come out much hotter at first, because of the water content. There's less water to boil out as you continue. I suppose at come point the wood dries out completely and starts to burn, but I've never seen that and I would hope to always stop long before that becomes an issue.

 

[Gary T Egbert]

That started as a one pound piece... from my limited experience, 2 minutes was a good choice. I've never done more than 5 minutes at a time, but that's on 8"+ diameter bowl blanks. I have also noted that the pieces come out much hotter at first, because of the water content. There's less water to boil out as you continue. I suppose at come point the wood dries out completely and starts to burn, but I've never seen that and I would hope to always stop long before that becomes an issue.

Scott, yes the pieces were about 6 inches round and had been turned a bit first. Big mistake as all the dimensions changed to oval and I did not have the space to cut them down so I started over. Now I have in the MW the same species and baking for 3 minutes each. These pieces are 6 in square 2 inches thick which I believe will dry nicely after which I will finish my wig stand, hopefully. I will back off on the time at some point too.

 

[Scott Hargrove]

Scott, yes the pieces were about 6 inches round and had been turned a bit first. Big mistake as all the dimensions changed to oval and I did not have the space to cut them down so I started over. Now I have in the MW the same species and baking for 3 minutes each. These pieces are 6 in square 2 inches thick which I believe will dry nicely after which I will finish my wig stand, hopefully. I will back off on the time at some point too.

Yeah, that's why I decided to start drying the blanks before turning them at all. I figured, from what I've always heard, the MW cooks from the inside out... well, sort of. Anyway, it doesn't have a problem reaching into the center of a piece.