Working with pressure treated lumber

[Danno30008]

Good afternoon:

I am going to build some simple flower planters for the front porch and have a few questions abot working with pressure treated wood. The main one being should I wear a dust mask when sanding? I read someplace that the dust from PTL is harmful to us/me if inhaled..

The other question is can I put a protective finish on it after sanding?

I did this when I lived in Chicago and it looked great! The light green color really came out good when we applied several coats of poly. I tried it again a few years ago and I live in Atlanta, and the results were not soo good.. After about 6 months, all the finish started to peal off and then turned yellow. I sanded the heck out of the wood and it came out like crap.:mad:
Anyway, can you put a finish over pressure treated lumber that is available today and if so what prouct and how many coats?

Thanks and take care
Dan

[aschueler]

Ah, finally a question I can answer. Living on a farm in Florida, we use a lot of pressure treated lumber.

First, think three or four times about sanding it and definitely wear a respirator. I don't think a mask is enough. The older pressure treated wood was arsenic based, and the newer stuff is copper based. Both are bad to inhale.

I am not sure about a protective finish over it; I wonder would you prefer to use cedar and cover that? Cedar is fairly rot resistant (it's what lines my garden -- the new stuff is less toxic, but it does leech into soil and might get in food crops). Also, the newer stuff tends to eat away at certain types of metal; I think you need to use zinc plated hardware to hold it in place. It might indeed destroy your finish.

We use pressure treated wood for our fences (cattle and horses) and most outdoor projects. It all turns grey. I think you can prime & paint it, but it's probably not worth it.

Cedar looks a whole lot better.

[Danno30008]

Thanks for the info.

Yea, I don't want to paint it, would be a pain to sand, prime and then a few coats of paint.

I really like the look when I did it in Chicago, but like I said, my last time the results were not so good.

The main reaon I want to sand it is I have some new toys and I want to play.. New planer, drum sander and table saw..:D

This is my first real project and I want it to shine so to speak, then on to a couple night stands out of walnut.

Anyway, thanks and I will post some pictures as I go along.

Take care

Dan

[Cocobolove]

I think it's gonna be tough to finish the treated lumber.* We can't even cover it with aluminum trim coil. In about a year the stuff eats through the aluminum. But, if we wrap it with saran wrap, we can cover it, no problems yet, (knock on wood)we've got a couple of jobs out there that we used the wrap and they've been installed for up to 3 years with no problems. I don't know a lot about different types of finish, but maybe the saran wrap thing will help someone come up with a solution.

[Don]

If you had good luck with coating/finishing PT lumber then it was probably a fluke. I wouldn't run PT through any of my equipment. Pick out the best stuff you can find for your planters and live with it if you can. PT is almost always wet/green in the center even if the outside is dry - that moisture is going to go somewhere, even if it has to push your finish off to do it. Exterior stains are about the only thing that really works on PT. If you are going to paint it then you need to wait until it is completely dry or use a breathable finish like stain.

My 2 cents.

dawjr

[bogydave]

Another question on treated wood.
What is the difference between the red treated wood for decks & the green stuff Dano is asking about? I one better than the other?
I framed a greenhouse with the green stuff.
I put a deck on with the red stuff & coated it with something similar to Thompson water seal, forgot the name, about 12 years ago. Still holding up.
I did another, newer, deck framed with the red stuff & covered it with "Eon" plastic deck boards & trim around a hot tub. I like it better but cost + expansion & shrinkage are big issues. (No maintenance :) ).

[Don]

Not familiar with the red stuff, Bogy. What does it look like?