The Woodturning Forum - Woodturner's Resource

Bruce Kamp

Active Member

Offline

WR Rocks!

Posts: 230

Kilns
May 28^th, 2016 at 3:40pm

I have searched the site using the search function but only found one listing dealing with kilns.
From what I can gather most of us will with green, or high moisture content, wood. I have seen a lot here about drying methods and measuring equilibrium moisture content (EMC). What I am wondering, does anyone use a kiln? I am talking about the "Easy Bake Oven" variety where there is an insulated box with holes, a light bulb as a heat source, and maybe a fan.
What success have you had? How long to get from 30% to <10% EMC?
Thank you.

Back to top

IP Logged

Register To Remove Ads

Ed Weber WR Administrator WR Patron Offline Posts: 8,939 Wilton California USA Gender: JET 1642 Grizzly G0584	Re: Kilns Reply #1 - May 28^th, 2016 at 3:57pm Bruce, I know there are a few members here that have made a refrigerator wood kiln. If you do a search for refrigerator wood kiln, there are YouTube videos PDF's and many webpages. Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to or
Back to top	IP Logged

Bruce Kamp Active Member Offline WR Rocks! Posts: 230	Re: Kilns Reply #2 - May 28^th, 2016 at 4:19pm Ed, Thank you. Yes, I have seen a lot of these. I guess I was more interested in hearing what member's experience has been with them. Are they effective, what sort of drying time do they achieve, that sort of thing.
Back to top	IP Logged

John Grace

WR Addict

Offline

Everyone needs a good
wingman...

Posts: 1,278

Bel Air
Maryland
USA

Re: Kilns
Reply #3 - May 29^th, 2016 at 7:45am

Drying time is going to be relative to:

Original moisture climate
Geographic region
Seattle vs Phoenix
Wood species
How thick the wood placed in the 'box'
Time of year
Your shop

Sorry...just a lot of variables. THAT said...I have seen several of videos where users claim the drying time from wet to final turning ready wood is two to three weeks. Good luck...John

Back to top

“If history were taught in the form of stories, it would never be forgotten.” Kipling

IP Logged

Gary D Baker

Full Member

Offline

WR Rocks!

Posts: 71

Re: Kilns
Reply #4 - May 30^th, 2016 at 5:50am

I built a refrigerator kiln a couple of years ago. Medium size rough turned bowls to dry enough to finish in 8 to 12 wks. I live in Colorado where humidity is low ... Kiln is now a place to keep stuff I don't want to get too dusty. I can't seem to get enough wood dry no matter what I do, so about 80% of my turning is natural edge and customers don't notice if it is warped or not.

Back to top

IP Logged

Breck Whitworth

WR Addict

Offline

WR Rocks!

Posts: 2,227

Gulfport
Mississippi
USA
Gender: male

PM 3520-B

Re: Kilns
Reply #5 - May 30^th, 2016 at 8:15am

Bruce,
I have two drying kilns made from an old upright refrigerator and an old smaller chest freezer. I use one 60 watt incandescent bulb and a small 110volt duct fan. in each. Through trial an error I found one bulb was enough two caused more cracking than I wanted. I also found it was very important to buy a small dial timer switch used for aquarium lights on coral reef tanks (inexpensive) I run both units for 12 hours straight then the timer turns off for about 8 hours allowing bowls to stabilize then the cycle repeats. The light bulbs and fan unit is at the bottom of each unit. I drilled holes at the bottom and top of units like you described. I got the idea from Cindy Droza but added the fan and timer from experience. They really work they will take a very large bowl that would usually dry in 8-10 months down to 5-6 months, smaller bowls from 6-7 months to drying in 3-4 months. I am talking about 16" to 18" bowls 1-1/2 inches thick to 8" bowl 1" thick
Without the timers and fan the bowls will dry in 2 to 3 months but crack and be almost useless

Back to top

May the Lord Bless the work of our hands! And Necessity is the mother of invention:

IP Logged

robo_hippy

WR Addict

Offline

Posts: 3,638

Eugene, OR
USA

Re: Kilns
Reply #6 - May 30^th, 2016 at 12:11pm

Breck, The on/off thing makes me think of a chat I had with a guy who dried his lumber in a solar kiln. He said it would get to 150 or so inside the kiln during the day. Then when the sun went down and things cooled off, it 'relaxed' the tension in the wood from the heat. I think the evaporation and condensation of the water helped too, as in steam during the day, relaxing through condensation at night. Had to be some sort of vapor release though. I was able to rip 8/4 boards with zero spring to them, so drying forces were equalized...

robo hippy

Back to top

IP Logged

Breck Whitworth

WR Addict

Offline

WR Rocks!

Posts: 2,227

Gulfport
Mississippi
USA
Gender: male

PM 3520-B

Re: Kilns
Reply #7 - Jun 4^th, 2016 at 9:48pm

Robo What you are saying makes sense to me.
All I know is the heating up then allowing the wood to cool down works for me and through trial and error (mostly error) and tons of research. I finally found that by doing this it slowed down the drying process some but it did relieve the stresses that caused the cracks. about 90% out of 20 I might have 2 lost to un-repairable cracks sometimes only 1

Back to top

May the Lord Bless the work of our hands! And Necessity is the mother of invention:

IP Logged

Register To Remove Ads

Ron Carrabotta

Senior Member

Offline

WR Rocks!

Posts: 450

Dawsonville, ga
Georgia
USA
Gender: male

Jet 1014 VS
Jet 1642 -2EVS
Lindow -White Rose Engine

Re: Kilns
Reply #8 - Jun 5^th, 2016 at 4:15am

I've been using the refrigerator/lightbulb method for the past few years with a lot of success
For the most part, I just weigh the pieces, put them in the box and just walk away. Weigh the pieces and record on a daily basis, recently lost a NIP bowl due to over heating .
After reading the above from Breck & Robo, I'm definitely going to be putting in a timer.

RC

Back to top

It is easier to be forgiven than to get permission!

IP Logged

Bruce Kamp

Active Member

Offline

WR Rocks!

Posts: 230

Re: Kilns
Reply #9 - Jun 5^th, 2016 at 10:47am

I bit the bullet and picked up an old freezer yesterday. Have ordered a Ductstatt to help me with control. Going to be drilling holes and hooking up the socket for the bulb.
My plan is to start slow. Lots of good advice here seems to say that slow-moderate is better than faster.
I do segmented work too. So, I won't lack for something to do while I wait for the blanks to dry.
Also bought an indoor/outdoor temp/humidity gauge. Not sure it will work inside the metal box.
Hope to post some results in a few weeks.
Thanks to everyone for the insights and advice.

Back to top

IP Logged