Solar kiln vs oven-style kiln


Denette

Recommended Posts

There are several lumber yards in my area.  The one closest to my house is a small-time operation that only has a solar kiln for drying their wood, while the others use the big industrial oven-style kilns.  They all dry the wood to the regionally appropriate 7-9% moisture content.  Does anyone know if there is a measurable difference in quality between kiln drying methods, or is it simply enough that it was dried in a kiln of some sort?

Link to comment
Share on other sites

Improper kiln drying can damage lumber.  Case hardening is a perfect example...cooking wood too fast which causes the internal fibers to tear apart.  I would always go in with the assumption - until proven otherwise - that a small-time dealer had no idea what they're doing, just to be on the safe side.  Kiln drying is a real science and it's common to screw it up.

 

Before you purchase a big load from any dealer, buy a small quantity, cut into the boards, see what they look like on the inside and how they react to the cuts.  A moisture meter would also be a good investment if you're buying from questionable sources...but there's conflicting opinions about the accuracy of meters in general, depending on which model you get.

 

Best thing to do is to find a trusted, professional dealer and stick with them.  I don't really bother with the backyard sawmill warriors because the quality is so uncertain.

  • Like 1
Link to comment
Share on other sites

I buy most of my lumber from two local yards. One is a smallish operation that uses a solar kiln and the other is actually Eric's yard (or the yard where he works at least) where I believe they source their lumber from the bigger distributors that use the big ovens. I've had good luck with both. I don't have a moisture meter but I usually let wood acclimate for a good while before I start using it. I think as long as the person/people in charge of the drying know what they're doing and take the time to do it right it doesn't matter.

  • Like 1
Link to comment
Share on other sites

  • 4 weeks later...

I have a small sawmill and kiln dry most of my nicer stuff in a solar kiln. I never have any issues with case hardening or wood movement. I do dry it much slower then most people with similar kilns. I have a very small vent for the humid air because I don't want the moisture to leave the wood to fast. I would describe my kiln drying process to be a sped-up version of air drying more then anything. Being that I don't force any moisture out of the wood and expel the moisture out of the kiln with dehumidifiers. I believe that's why I've had so much luck with it, I don't rush it. I can dry 5/4 and 6/4 black walnut to 6-8% moisture content in 6 weeks. Not nearly as fast as a commercial dehumidification kiln could dry it, but my method is working for me and I have little to any checking and everything comes out flat.

Link to comment
Share on other sites

I have a small sawmill and kiln dry most of my nicer stuff in a solar kiln. I never have any issues with case hardening or wood movement. I do dry it much slower then most people with similar kilns. I have a very small vent for the humid air because I don't want the moisture to leave the wood to fast. I would describe my kiln drying process to be a sped-up version of air drying more then anything. Being that I don't force any moisture out of the wood and expel the moisture out of the kiln with dehumidifiers. I believe that's why I've had so much luck with it, I don't rush it. I can dry 5/4 and 6/4 black walnut to 6-8% moisture content in 6 weeks. Not nearly as fast as a commercial dehumidification kiln could dry it, but my method is working for me and I have little to any checking and everything comes out flat.

 Do you have a description or plans for a solar kiln?  I replaced 10 single pane windows in my house, but I kept the old windows, with the intent to build a greenhouse.. But if I can use them in a home kiln, that would be a better use of them for me!

Link to comment
Share on other sites

I have a small sawmill and kiln dry most of my nicer stuff in a solar kiln. I never have any issues with case hardening or wood movement. I do dry it much slower then most people with similar kilns. I have a very small vent for the humid air because I don't want the moisture to leave the wood to fast. I would describe my kiln drying process to be a sped-up version of air drying more then anything. Being that I don't force any moisture out of the wood and expel the moisture out of the kiln with dehumidifiers. I believe that's why I've had so much luck with it, I don't rush it. I can dry 5/4 and 6/4 black walnut to 6-8% moisture content in 6 weeks. Not nearly as fast as a commercial dehumidification kiln could dry it, but my method is working for me and I have little to any checking and everything comes out flat.

Where are you located?

Link to comment
Share on other sites

Do you have a description or plans for a solar kiln?  I replaced 10 single pane windows in my house, but I kept the old windows, with the intent to build a greenhouse.. But if I can use them in a home kiln, that would be a better use of them for me!

Richard here is a place to start.

http://www.builditsolar.com/Projects/WoodDrying/wood_kiln.htm

Link to comment
Share on other sites

Why, thank you Wood. I really hadn't even thought about drying wood till this thread. I live in a good place for domestics here in middle Tennessee. I can get fresh milled oak for .30 a bd ft  Poplar I can get for .20 ft  Being in no hurry, 5 or 6 weeks is no big deal!  Again, thanks, oh, I used to live in Ocean Grove, NJ before they changed the Sunday parking law!

Link to comment
Share on other sites

Here is my solar kiln.  I made it a year or so ago.  It is a simple 2x4 frame wrapped in plastic sheeting.  All seams are sealed with house wrap tape.  Inside I put a dehumidifier with a drain hose and a small fan to keep the air moving.    Probably have about $20 in it and it was saved me hundreds.  It needs new plastic now though.

 

https://instagram.com/p/rnPpFxlSLJ/?taken-by=mds22

https://instagram.com/p/rVeQjUlSD7/?taken-by=mds22

Link to comment
Share on other sites

Mds, how long, in your experience, does it take to go from wet wood to workable dryness?

 

Honestly, I can't even say.  I cut down some walnut trees and stacked the lumber for a couple months to air dry.  Most of it was 8/4 or 12/4.  Then I cut down a hackberry tree and decided to build the kiln. I put the walnut and hackberry in it.  For the first few days I was getting a couple quarts of water out of it, which gradually declined.   I ran the kiln for about 2 months, then removed all the 4/4 lumber in it.  Then left all the thicker stuff to air dry over this last winter.    I wasn't in a huge rush to dry it, I just wanted it to be ready to use this year and it all was.  

Link to comment
Share on other sites

Do you have a description or plans for a solar kiln?  I replaced 10 single pane windows in my house, but I kept the old windows, with the intent to build a greenhouse.. But if I can use them in a home kiln, that would be a better use of them for me!

I don't have plans, i used ideas from pictures I've seen online. Honestly it'll prolly be more work then it's worth using the old windows. I used clear corrugated roofing from Depot. Super easy to install and you don't have to worry about it breaking.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.