# Use a sauna as a kiln for drying?



## PoleVault (Oct 11, 2014)

I know this may seem strange or stupid… But I was wondering if anyone has ever used a dry sauna as a makeshift kiln for drying smaller boards to speed up the drying process for a project or two. I have access to a large dry sauna that is always running and there is pretty much no one ever using it. It has some great area under the benches where I could put some boards and let them sit in there for a few days or even weeks of I wanted… Is this just a bad idea?


----------



## runswithscissors (Nov 8, 2012)

I can't verify this, but I have read (as in Billy Atkin, naval architect) that steaming white oak for bending actually seasons the wood. I think the heat, even though wet, drives the moisture out of the wood.

I'd be curious to try a few sample boards in your sauna to see what happens.


----------



## HornedWoodwork (Jan 28, 2015)

Hmmmm…Depends on how green the boards are when they go in I'd wager. In traditional kilns the temp is brought up gradually and then left there for a length of time like a month to 90 days.

If you have green wood and stick it in a super hot sauna I am fairly certain that the outside of the boards will dry quickly but the inside of the board might take much longer and than can lead to warping and cracking. Even if this doesn't happen you might end up with girdled boards that warp when you cut or plane them.

If your boards are MOSTLY dry and sufficiently thin (like 3/4) the sauna will probably dry them out very quickly and might not cause much harm, but I would test it on a few boards first.


----------



## pintodeluxe (Sep 12, 2010)

It depends on wood type and moisture content. Some species like white oak will check badly if you dry them from green. However if the lumber is air dried to approx. 15% moisture content, then you can stack and sticker lumber in the sauna to dry it.

A kiln has three components to effectively dry lumber
1. heat
2. airflow
3. low / controlled humidity

A sauna is hot and dry, but there is no airflow. Still I think it would work if the lumber is air dried outdoors first. Add fans for more even drying.


----------

