I got a customer that wants me to dry pressure treated.
Anyone got experience with this??
Is there a hazard with the chemicals in pressure treated and the heat in a kiln? It seems I've got more questions than answers on this one.
I did not learn about drying pressure treated material in kiln operators school. :P
Any help is appreciated.
Mark
I don't have a clue on this, but its a great question... I've seen lots of info on milling PT and all the nasties involved...
does PT ever really dry? I know the 4x4 pt poles in the middle of the stack are much dryer and lighter than the top of the stack thats soaked... at least at home depot they are.
I read in one of the Government bulletins that you should not re-dry pressure treated wood in a kiln. The heat will neutralize the chemicals. That's all I know about that. ::)
About drying pressure treated wood, I found this article.
http://www.fpl.fs.fed.us/documnts/pdf1995/boone95a.pdf
Seems it addresses the question a bit.
Lots of misinformation out about CCA which was unfortunate, but the media liked the twist, so eventually the treaters just decided not to fight it. They couldn't win that battle, but we lose, and the timber resource, protected from overuse by long-term use of wood, loses as well. The odds of beating the do-gooders and tree huggers is slim to non, IMO.
In the meantime, the treaters are treating with chemicals that appear safer, but that don't protect our wood resource as long. So they probably make more money in the long-run. We lose.
All CCA treated wood should be kiln dried (KDAT) after treatment to make sure the chemicals are neutralized. Then it is absolutely safe to handle. If not, there is a risk that some of the chemicals do not go through fixation and you have loose copper, chromium and arsenic on the matreial. The chemical reaction is heat sensitive so as long as the wood gets to about 130F, it is fine. Dry it like any fast drying softwood. Be sure not to heat it too fast. If you use a dehumidifer, the water is perfectly safe. We have had it tested many times and there will be no carryover. If the industry had done that all the time instead of only when required for certain things (playground equipment, foundations, railings etc) they never would have been faced with the phaseout. But is cost a nickle a BF to do it and the treaters fought it. dumb