Paint on Brick Chimney (Removal?)
ChipTam
| Posted in Energy, Heating & Insulation on
We recently purchased a 120 year old house for a vacation home. An older wood stove was connected to a painted brick chimney. We’re going to be installing a new wood stove and were wondering if the painted brick should be considered a combustable surface? It looks like there are at least several coats of paint (probably oil-based) and, while the paint is not in all that bad condition, there is some evidence of blistering. Should we scape the loose stuff and re-paint or remove the paint?
If we need to remove the paint what is the best product to use? One friend suggested muratic acid but others have said to use a paint stripper.
Replies
Muriatic acid won't have much effect on old alkyd paint- it's meant to remove efflorescense on brick (the whitish residue which shows up when there's been water seeping through the mortar).
As far as removal is concerned, I wouldn't be concerned about combustibility on a chimney exterior surface unless it's enormously thick and flaky (then again, it's not my house!). If you like the look of it, re-paint. If you think it's ugly, remove it- but beware- it may be very ugly brick (as was the case with the only chimney I've ever stripped...). There are many commercial strippers on the market- some safer but less effective on well-cured alkyd paint, and others which contain methylene chloride and are very nasty but seem to work very well. The third option is a heat gun- no worry about damaging the brick with that method, but you'll probably have to do some chemical or mechanical cleaning afterward in any event.
I'd recommend you try sandblasting a small test area, except for the worry that the old paint has lead pigments in it. Even the more toxic strippers may be preferable- depends which poison you prefer...
Thank you and thanks to Bob for your replies to my question. I think that the only reason I would try to remove the paint from the brick would be if there is a fire hazard when the wood stove is placed close to the painted chimney. From what I can see of the unpainted brick in the attic, the chimney won't win any beauty contests even after the paint is removed. If I do decide to remove the paint you've pretty much outlined my alternatives. Thanks again.
Chip
I attempted stripping the paint from a chimney once. Paint strippers weren't effective in removing the paint in the pores of the brick and abrasives, wire wheels, etc. just took too much of the ancient brick away.
The final solution was to remove all of the paint possible without damaging the brick then repaint it with a 'brick red' paint. This looks fake and terrible, of course, so then go back and sponge paint the shiny red surface with a dilute black paint. Wipe off any excess. This dulls the finish and creates shadow lines around the texture of the brick.
It's a convincing effect from about 4'. If you're closer and paying attention, you can start to see the paint texture.
Thanks Bill. That sounds like a possible plan. At the moment, the chimney is painted an off-white with no attempt to hide the fact that it's painted. It doesn't look all that bad and another plan might be to just re-paint with a similar color. I'll think about it over the winter. Don't need to make a decision until next spring.
Chip
The paint will be deep into the pores of the brick unless it is really smooth brick. Lots of scrubbing with a brush. You could mask off the walls and floor and ceiling, make a curb for the floor and pressure wash it. Messy, but no solvents. The paint may char and get pretty nasty near the flue if you run the stove. Depends on how far away the flue pipe is. The heat won't come through the brick much. It radiates more from the pipe. If you strip and repaint, there are high temp paints made for grills and engines. Those will not char or discolor as much. Not a lot of color choices, but they do have it in chrome. (plus black & white & red if you're less adventurous).