DH Kiln

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by dwicked posted 10-25-2018 04:55 PM 528 views 1 time favorited 7 replies Add to Favorites Watch
View dwicked's profile


7 posts in 488 days

10-25-2018 04:55 PM

Hello all first post.

I am looking for some guidance on running my kiln I built. pulling a lot of inspiration and education from a Feb. Wood working journal (I think) magazine article I am looking for more detailed info on the schedule.
its an 12×8 outside dim kiln built indoors in my wood shop I run 2-4 fans ( might upgrade them reply soon) a home dh unit. It’s 2×4 construction with r 13 insulation with vinyl vb and thenthen finished of inside with 1in foam. The dh keys it at 90-100 and my little heater gets it to 116 but not relly any more I think it shuts off.
i do slot of sycamore and maple and elm oh and poplar that’s what I have a plethora of. (like over 200 logs) I have a sew Mill so I can quickly go into the kiln if that’s necessary. Maybe if there any Washington wood workers here maybe You all would be interested in some wood I am open to custom cutting. First batch was OK but I had a few weird spots that have a really high mc reading on my Wagner like 1-2in x1-2×1-2 area but the rest is under 8 just want to make sure I am doing it correct. OK ready set go.

7 replies so far

View pintodeluxe's profile


6065 posts in 3453 days

#1 posted 10-25-2018 05:09 PM

It was the May / June issue of Woodworkers Journal that featured the dehumidification kiln. I actually wrote that article. Glad to hear you built a kiln, it’ll be a great resource for you. 116 degrees F is plenty hot to dry lumber, so long as you have strong airflow throughout the stack. For sterilization you’ll need a bit hotter.

The fans are an important part of the system. My first improvised kiln used 3-4 really cheap box fans, and they didn’t move enough air to get the job done. That’s why I switched to attic fans.

Good luck with it.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View dwicked's profile


7 posts in 488 days

#2 posted 10-25-2018 07:17 PM

omgosh you are willy i tried to send you a fb question about it last night then i remembered this place and decided to join. i have a couple questions if you do not mind.

does it matter where in the kiln the dh is.

whats the best way to convert a conventional schedule to dh or even follow one at all.

i was getting 8-10 gallons a day for a few days then it kinda dried up to just a trickle is this normal?

do you use the dh humidistat to step down the rh or just crank it up and let it go. i usuly let them air dry for a week or two before going in the kiln loading it up for run no2 today. Sycamore and ambrosia maple Qsawn and a few slabs.

i have a couple hundred logs i am sawing and a local yard is taking some where is another good place to get rid of some more i can easily custom cut but i am getting so much wood right now it silly.

i am in Kennewick WA so not far but not near a metro area. this is a side gig that i actually enjoy and would like to grow it thinking about selling my other company. it all started so i could make wood for projects love the gng and craftsman styles. thank you you did a wonderful article.

View pintodeluxe's profile


6065 posts in 3453 days

#3 posted 10-25-2018 08:28 PM

I air dry all my lumber for a year before it goes in the kiln. This helps me minimize loss due to warpage etc. If you want to dry green lumber, I would do your research to see what you can expect. Then start with small loads to experiment and see what kind of quality the finished lumber has.

It’s normal to pull a large quantity of water at first, then it dries to a trickle. But, that doesn’t necessarily mean the lumber is dry to it’s core. That’s where a good moisture meter comes in. Keep drying the lumber until core samples read at 6-8% (or whatever your goal M.C. is). It can be a fun process.

I step the RH down gradually, but I’m probably being overly cautious because my lumber is already air dried to 15%.
Good luck!

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Ocelot's profile


2395 posts in 3278 days

#4 posted 10-25-2018 08:55 PM

This is the kind of thread that makes this site worthwhile!

A man came with a question and found the best person to answer it.

I haven’t seen that article. I’ll have to check it out.

There is a guy near me that dries everything 40 days in his kiln. Another guy dries white oak 60 days and poplar 10 days. Seems like it all depends on how fussy you want to be and how businesslike.

View AZWoody's profile


1477 posts in 1863 days

#5 posted 10-25-2018 11:41 PM

I am looking into either a solar kiln or DH kiln but at those quantities of logs that you’re going to be milling, wouldn’t a commercial model be better, like a Nyle or Woodmizer?

From what I’ve been reading, the tannic acids will deteriorate a home dehumidifier unit before too long so you won’t have much longevity before you have you are buying new ones.

Also, with the commercial ones you can program the proper schedule based on the species.

Not to dissuade you from DIY which I’m really looking into myself but those numbers just sound a bit over the top for even a serious hobbyist kind of kiln.

View dwicked's profile


7 posts in 488 days

#6 posted 10-26-2018 04:21 AM

I totally agree commercial one would be sweet and I’m hoping this will work up to that I’m supplementing some of my income from doing this and each load easily justifies a new dehumidification unit but I’m not expecting this one from the tannic acid to go very fast as we have about 10 years and have no ill effects on our Cooling condensers in our fermentation room where we store all of our Oak barrels and ferment Chardonnay in there it just didn’t seem to be near as big a deal as some of the salesman in the wine industry made it out to be I bought one stainless and one conventional and I can’t tell who’s been a difference that the three almost four times the money got me by going stainless as to the amount of trees on the ground I’ve been able to be very fortunate and stumbled into some large grabs and they can just lay there and I’ll take what I can take I’ve got a few acres to store them so I’m good there but have a pretty good heavy Supply so if I can feel my kiln or a second Kiln once a month make some money definitely justifies my hobby keeps me out of the race car which that alone saves a lot of money thank you guys to all the help this has been a very warm welcome I’ve always been a bit sheepish and never really took part in these sites but you guys have encourage me to keep contributing and going

View Fresch's profile


464 posts in 2560 days

#7 posted 10-26-2018 12:27 PM

I like mine aged 12 yrs. or more rocks.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics