Removing paint from masonry?

[tabasco]

I am painting an old cabin with a cement block chimney. The paint on the chimney is peeling in places and I'm thinking the best thing is to chip the old paint off completely before repainting. Are there special tools for stripping this old paint off of the cement blocks? I don't care if the surface is gouged up a bit. I can resurface the masonry before painting. If it were wood I would use a belt sander, but the cement blocks would just eat up sandpaper. Anybody got ideas?

[Stinky The Clown]

1. How about a pressure washer?

If your plan is to repaint, you need only remove the loose material. If you choose this route, be sure to allow it to dry **completely**. The concrete will retain moisture for a good while. I'd let it dry for as long as possible ..... even up to a week.

[tabasco]

2. Thanks for the advice.

I saw one at Lowe's yesterday, 3000psi, for about $400.

There are some parts of the chimney that had been hastily repaired that I want to level off as well. I'm thinking a grinder for that.

[Longhorn]

3. You can also rent them.

Good luck with your project! :hi:

[Warpy]

5. Seconded, a power washer will blow the most crap off

but yes, I'd let it dry for a week, too. I'd also use specific masonry paint, probably not done with the last painting and probably why it failed.

[Viva_La_Revolution]

4. Pressure wash first, then use a stiff metal brush

to get all the little bits. It takes time, but the next coat will last forever.

after scrubbing, don't forget to rinse it down again and dry completely before painting.

:hi:

[tabasco]

6. FYI - good tip I got from a kid working for me.

I have a 4" Makita portable grinder. There is a wire brush attachment for 4" grinders (it says for bench grinders but it fit on my portable deal). I tried it out and it works pretty good. It will take a couple days but it will remove almost all the paint. It will take maybe three of these wire wheels as they slowly get smaller through use. They are about $5 apiece. The high rpm of the grinder works okay. A drill doesn't have enough rpm. I'm glad I found something to use my grinder for other than cutting metal poles.

[Stinky The Clown]

7. The only downside is that wire wheel, if used as the only paint removal medium/device .......

.... removes some of the brick along with the paint. Depending on the type of brick, its surface may be much harder than its center. And the hard surface may not be very deep, leaving you with exposed softy brick .... which will wear/weather/spall pretty quickly. On the other hand, the brick may be equally hard all the way through.

I'd be very careful about using a wire brush as the sole paint removal method.