Beginners question about PT

[TimRice]

Is there any reason to NOT run seasoned (~1 year old) Pressure Treated (PT) lumber over a jointer and through a planer? (Other than the usual warning to not breath in the dust!) Will it bother the blades or cause problem with other woods fed through the equipment later?

 

[johncolvin13]

You sure are right about the dust. That stuff is terrible for anyone to work with. I have found that PT (I call it Greasewood) will dull tool edges much quicker than most any other woods. I do nnot know if it is the chemicals or the moisture. If I were to have to, and I repeat have to plane or joint PT I would put old knives on my equipment, and then thoroughly clean my machine to remove any of that caustic dust.

Us cypress if you could.

 

[hannah01]

Yeah, I would be cautious. I recently did some work on my deck with PT lumber, and I broke two drill bits and a jigsaw blade. :BangHead: Granted they weren't expensive bits/blades but the same ones haven't broken on non-treated wood under greater stress.

 

[Ryan]

Another word of caution- the chemicals and moisture in PT lumber usually cause it to be really sticky(the dust, that is), so get it off of your machines as soon as possible. I still have some stuck to the dust chute on my mitersaw over a year after it got there!:BangHead:

 

[DaveO]

SYP, Southern Yellow PIne is a harder wood than most think and it is often quickly dried resulting case hardening. The pressure treating chemicals are not something that you want in your body, although the new ACQ treatment chemicals is supposted to be safer than the old CCA, the jury is still out on the dangers of CCA, IMO. But if you would run a piece of hard Maple, or an exotic like Paduak, or Purpleheart through your machines why wouldn't you run something that isn't as hard. The only drawback is the SYP does tend to gum up your blades, so clean them before you run something else or you might get some burning BTDT:slap: Dave

 

[clowman]

FWIW, they do make blades for PT wood. I know it's a little off the topic of running them through a planer and jointer, but good to know.

 

[DaveO]

Clay, what is a blade for PT wood...a sharp one.:lol: It's not like MDF or Plywood with glues and binders, it just pine with a Alkaline Copper Quanternany (ACQ) compound added under pressure. The only problems I've ever had working with PT wood are binding due to case hardening and getting splashed in the face by the juices. Count on it shrinking across the width mainly but a little along the length. It cuts like any other wood. Dave

 

[clowman]

I believe it was treated with a special covering to keep the blade from gumming up so bad over time. Maybe it is like buying "undercarriage rust coating" on a car.. if you know what I mean. Of course, I'll not deny I was on something when I "thought" I saw the saw blade....

 

[DaveO]

The coating would make perfect sense, 'cause i think that I've ruined my mitersaw blade with all the PT wood I've run through it. I make a lot of outdoor, landscaping type things, so it has been abused. Need me a new Freud blade, and all will be right. Dave

 

[McRabbet]

Maybe that $1 off jointer from Tradesman that was posted earlier won't gum up! ;-)

 

[TimRice]

Just don't forget to stock up on extra 'coated' blades!!:mrgreen:

 

[clowman]

Or prehaps a $4 Harbor Freight special for PT?