hey guys,
I think I already posted this question on somone elses entry, but it must have been old cause now i can’t find it. I am gonna try again and make my own little thingy here….
I am working on resawing a bunch of doug fir beams for flooring that will have radiant heat under it. i am concerned that the wide panks (10″ after milling) will check, cup and shrink after the heat gets turned on next fall. I have done some furniture with this resawn fir and even though it was old, it shrank about an 1/8″ per foot in my hot apartment.
my idea is to rip them (bandsaw) and try to makeshift some kind of kiln and then dry them out for a few weeks, before milling them. Will this work? how long does it take to get stuff dry, and at what temp? Is it a mistake to install it at it’s smallest deminsion in case it needs to expand ?
also I wonder whether sealing the back side of the flooring as well as the front might make it a little more stable.
Does radiant heat cause more problems with wood floors in general?
any one who knows about drying wood, help me!
peace, softy
Replies
ho boy. Yer in over your head with that many questions, and I don't mean to dog on you, but really. There's a lot more to it than heat and time, missing one of those little important things stands a good chance of ruining the whole batch. You need heat, time, moving air, a way of measiring the MC of the wood, a way of measuring how much moisture is coming out of the stack each day. You want a period of fairly high heat, and with many species, you want to pull it below the intended point slightly and hit it with steam to bring it back. Helps prevent case hardening. Taunton prints a book - Lumber and How to Dry it or similar title, which might give you more answers to specifics. There's also lit out there from the Forestry service, and there's periodicals dedicated to sawyers, any of which would get you closer to knowing what you want than I will. It takes books.
" Shoot first and inquire afterwards, and if you make mistakes, I will protect you." Hermann Goering to the Prussian police, 1933.
Post this over in Knots. This is more of a "furniture" type woodworking question. I surf both areas since I'm an ex-GC and am making furniture now. The folks there will help for sure.
John
The responses you're getting are right on, but once you get the info on the drying process, there are a number of ways to construct an inexpensive kiln using some cheap materials, a small heat source and a dehumidifier. The wood you plan to dry is already halfway there so you just need to put some basic technology together to get the MC consistent with the environment it will eventually reside in.
One poster mentioned steaming near the end of the drying process (conditioning) ...this is a step that is, unfortunately, omitted in most modern dry facilities, but especially if the wood is to be milled or ripped or resized after it's dried, this step will eliminate a lot of waste of the material and frustration on your part.
And as you start to understand wood drying, bear in mind that you're not after the efficiency of high production so you can take things slow and easy with a narrower wet bulb/dry bulb depression.
If you're interested in really becoming schooled up on wood drying, try to get a copy of "The Dry Kiln Hand-Book" by J. L. Bachrick, published by H.A. Simons Ltd., Vancouver, B.C. Canada.
where are you and do you have space to do this inside?
If so it can be done simply and fairly quickly (figure about a month per inch of thickness) if outside it may take several years depending on a lot of factors...
solar kilns can be made cheaply with clear plastic and a basic framework.
all of them require more than rules of thumb..
Where ya been Frenchy? Haven't seen hide nor hair of you or Dick Chaney lately. Have you been hangin' out with the VP at an undisclosed location? :-)
hey thanks for the advice, I am working for a couple that is rehabing a factory building and wants to use the old framing for floors and fixtures. There is lots of space to build a small kiln room, and I have about six weeks until I need to start milling it. I imagined I could build a small free standing shack out of ply wood with an electric heater on one end and a tiny exhaust fan down low at the other. I guess that I should relay go get one of these books that have been suggested. the back priming idea seems like it would have to help though, it just seems like that big open face on a pretty thin board (1") just makes the thing so much more suceptible.
again, thanks for all your help, this was just the thing i needed.
softy