iDRY Vacuum Kilns


How to dry eucalypt?

Started by David B, March 05, 2024, 12:39:05 PM

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David B

Seeing posts by @longtime lurker in another thread reminded me of this question. We have tons of Euc here in socal and it mostly goes to firewood if anything, since it's so hard to deal with (once dead and dry) and the climate is warm enough to not need much heat. More  a camp fire wood thing. 

At any rate, the wood (mostly red gum) is gorgeous and I'd like to make use of it, but have never found a definitive answer on drying it. I have some fresh and some dead and down for 20 years, some in between. It seems to dry from the center out and crack between the growth rings...splits more easily that way too. 

I'm all ears :-) Thanks 
Machine and welding shop day job, trees after work.


It dries similar to a soft maple.
Nyle Service Dept.
A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
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I just remembered, it is very prone to defects.
Nyle Service Dept.
A common mistake people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.
- D. Adams

David B

Yes, cracking is what I'm trying to prevent. It's very dry here. Need to slow it down somehow. 
Machine and welding shop day job, trees after work.


Slow drying helps. If you are a hot dry area, shade cloth around the stack should help. Contrary to drying most woods, you want to SLOW the drying. So under cover and shade cloth would be my plan. Then plan on a lot of defect that you trim out later. 
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)


When we dry live oak, we try to dry it slowly.  We cover it with shade cloth like was mentioned but also use 3/4" stickers instead of 1" and we stack it to air dry in an area that is protected from the prevailing winds.  Then, we let it sit there for a long time and check the MC every once in a while, to determine when to finish it in the solar kiln.  We've only dried eucalyptus once and it dried okay, but we are very humid here. 

longtime lurker

My apologies, I've been avoiding this post for weeks for want of time to give a complete answer. 

There's something like 700 species of eucalyptus. Toss on a couple hundred more to cover the corymbia and angophora families and you've got a long list of mostly Australian "gum trees" to choose from in the family Eucalyptae.
Common names are even more complicated because of local variations. So the "red gums" you've got could be any of a dozen species known as red gum in Australia or something else entirely. 

I did a look online to see what eucalypts were common in california and most likely what you have is either river red gum or forest red gum. I saw a lot of FRG,  river red gum i have no experience with.  Both are common commercial species here and generic kiln schedules are in print. If you could identify which species you had I could type you a schedule, but for now let's stay with general advice.

End seal your logs as soon as possible after felling and mill promptly.
Strip them out and let them dry as slowly as you can to below 20% MC.
There's a pretty fair correction factor between meter readings and actual moisture content in the eucalyptus I regularly saw, again there are published correction factors and knowing what species you have would help.
Once they've got no free water left they can go to kiln. Big charges, low temperatures and low water removal rates are the way to go.

You can't dry most eucalypts too slow. You can dry a lot of them too fast however.

See if you can figure out what species you have and I'll try and get you some more detailed information. I just don't have time to type up details for different  species on the hope they're the right ones.

The quickest way to make a million dollars with a sawmill is to start with two million.

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