One more question about drying

[Peter Blair]

I am trying to dry some hollow forms and bowls using a 'Boot and Glove Drier'. I wonder why I have not read about anyone else doing the same. It seems so logical to me if the idea is to encourage the wood to dry from the inside of a bowl or hollow form. I have constructed several different types of holders or stands for the turned items to sit on or to slide onto. It seems to be working for me. MY test pieces seem to dry about twice as fast as if I left them sitting around in my shop and so far so good as far a checking goes. Keeping my fingers crossed.

[Reed Gray]

Hmm, never thought of that one. First question would be is the air heated, or does it just blow shop air into the inside? Always a concern for me if I am using air that is too warm.

robo hippy

[Peter Blair]

Hey Reed. You can choose to use heated air but it is not hot or just air

[Glen Blanchard]

Pete - So how quickly are they drying now?

[Peter Blair]

Glen the experiment is not too scientific. I dry them until they no longer lose weight and it 'seems' to me they dry in about half the time it would take for them to dry just sitting in my shop. I usually run with the heat for one or two sessions at the beginning then just the air. The real trick is to get the air to circulate. It's easy to sit them on the dryer but not so easy to encourage circulation.

[Peter Blair]

Ok, so I went a little or a lot more scientific.
Today I turned two similar shapes although they were not the same size but the results show that the boot dryer without heat dried nearly 3 times faster than a piece sitting in my shop. Sample A dried in the shop Sample B was on the boot dryer.
For me, these results prove my 'Boot Dryer" method works twice as fast compared to just letting a thin piece dry. I should mention that the piece were turned to about 1/8" thick.
Note: As John Spitters suggested this process works best without heat. I did experience some minor cracking when I tried heat!
Here are the numbers



Starting weight
6 hours later
Weight loss
Weight loss per hour
% loss
% loss per hour


Sample A
6.94
6.52
0.42
0.07
0.06
0.01


Sample B
4.33
3.59
0.74
0.12
0.17
0.03



Sure hope this is helpful!

[John K Jordan]

Interesting. Once you get enough samples it would be nice to know if there was a change in the percentage of failures with or without the air. The thin walls should help.

Another John Jordan (the famous one) showed how he starts the drying process immediately after hollowing by getting rid of much of the free water - he pressurizes the inside with an air compressor. It was surprising how much water bubbled out of the pores.

JKJ

[Glen Blanchard]

Indeed interesting. Could you take a pic or two of your setup? I'd like to see exactly what you are doing.

[Jay Mullins]

Any pictures or drawings of the boot and Glove Drier?

[Peter Blair]

I'm sort of the guy who doesn't clean his shop until I need an excavator! So please excuse the mess.

The first photo is of the cheap boot dryer. It comes with a heat option and up to 3 hour drying time. If it wasn't for my grandkids using it for of all things to dry their boots I'd remove the timer option.
The second and third photos show a few of the plastic pipes I'v cobbled to allow me to dry just about anything I want. The most difficult for me is a hollow form with a small opening. It's quite hard to get the air to actually circulate.
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Oh, Oh, it looks like my new to me small metal lathe managed to sneak into this thread . . . on the turret is a small live center that I made a day ago for my oneway live center. It's about half the dia of the one that comes with.

[Bob Bergstrom]

I know a guy who turned lamp basis from birch logs. He shaped the outside, and drilled a hole down the center. He used aquariums pumps attached to a plastic hose witch he inserted in the hole. He had a basement full of drying lamp bases. I'm sure some cracked, but that might have just been some character added to the base that ended up in someones cabin in the north woods of Wisconsin.