Best Tool for Stripping Paint from Masonry

[Bull]

Years ago, I pained my terrifyingly dark, dank and spider-filled basement walls with a very bright blue paint. It was cheap, and made the space far less gross feeling. But now, it is time to get rid of it and paint the walls white. I would also like to paint the bare masonry with Drylok, since I do have a moisture problem down there.

The upper third of the wall is brick, and the lower two-thirds are concrete with a rough texture. So, I have lots of nooks and crannies.

So far, the best method I can think of to quickly and thoroughly strip the walls is an angle grinder with some type of wire cup attachment. Is there a better tool for the job? Anything that will minimize the dust cloud that I am going to create?

 

[walrus]

Years ago, I pained my terrifyingly dark, dank and spider-filled basement walls with a very bright blue paint. It was cheap, and made the space far less gross feeling. But now, it is time to get rid of it and paint the walls white. I would also like to paint the bare masonry with Drylok, since I do have a moisture problem down there.

The upper third of the wall is brick, and the lower two-thirds are concrete with a rough texture. So, I have lots of nooks and crannies.

So far, the best method I can think of to quickly and thoroughly strip the walls is an angle grinder with some type of wire cup attachment. Is there a better tool for the job? Anything that will minimize the dust cloud that I am going to create?

Chemical stripper? Pressure washer? Other than that its going to be mechanical and dusty

 

[Mickey O]

Pressure washers work great but I don't know about using it in a basement. If it's unfinished (hopefully with a drain) without a lot of stuff in it you can put up some visqueen where you don't want water and have at it. I've used a pressure washer inside. Heat and scrapers? Wire brush? Wire brush on power tool?

If the paint is 'secure' (adhering well, not flaking, bubbling, peeling, etc.) why not just paint the Drylok right over what's there.

 

[Mickey O]

Chemical stripper? Pressure washer? Other than that its going to be mechanical and dusty

I wouldn't use chemical stripper because some of it will get absorbed and make the new paint difficult to adhere unless you get it all off.

 

[flashpuppy]

Find a local mason and ask where they buy thier "detergent". It is a strong acid used to clean the excess mortar off of finished brick work. It works very well.

MAKE SURE TO USE YOUR PPE!!!!! This stuff is NASTY. Gloves, respirator, NO exposed skin.

 

[Busted_Knuckles]

Ive got a hot water (almost boiling) pressure washer, does a great job removing paint, latex is real easy, it will take up enamel pretty quick, about the only thing that takes a while is a well attached epoxy urethane. Hell, it even use it for rust removal, but it has to be hot-hot, it will take the layers right down to almost clean steel. The heat is more of the function than the pressure. If you dont have heat, I wouldnt bother using water. I know that because I can turn the heat off, without the heat, I wouldnt even bother using my pressre washer for much of anything. Just a thought, Bill

 

[Jononon]

Drylok over existing paint will do almost nothing, you have to apply it to the substrate, but Mickey O is otherwise right, there's a risk of any chemical stripper damaging the new coating.

To avoid that the options are abrasion (sand blasting is most effective, but wire brushing is feasible) or, perhaps more practically if you aren't going to empty your home of all its contents first, to use a chemical stripper, but to follow this up with a water recovery surface cleaning tool on a hot water pressure washer. This consists of a cowl with a port for a wet vacuum, so the bulk of the waste water is captured.

It may be possible to use a pressure washer without recovery but vacuum recovery avoids both the risk of flooding and that of working in a miasma of atomised paint and paint stripper.

IMHO, this is a job where it may be more appropriate to hire someone than to DIY, once time and the costs of suitable equipment are taken into account.

 

[Jononon]

Find a local mason and ask where they buy thier "detergent". It is a strong acid used to clean the excess mortar off of finished brick work. It works very well.

MAKE SURE TO USE YOUR PPE!!!!! This stuff is NASTY. Gloves, respirator, NO exposed skin.

You'll know you've made a mistake when you blow your nose and its lining is left behind on your Kleenex. Works well to clean brickwork of general dirt, but it's not particularly effective on some masonry paints, caustic paint removers work better and are somewhat less hazardous.

 

[Bull]

I rarely hire a professional if I can help it. This seems like a potentially dirty or tedious job to me, but one that I can and should do myself.

The paint on the wall currently is, I believe, latex. It is bubbling in quite a few areas, where moisture from the wall caused it to lose adhesion. The bare wall really needs Drylok.

A power washer or sand blaster sound potentially more messy than a wire cup and grinder, so I will probably avoid them. And anything that might cause me to lose my nose lining into a tissue is out, too!

Other than a wire cup, is there anything better to use in my grinder? 3M makes some flexible plastic jobbers:
http://www.eastwood.com/bristle-disk-4-1-2-in-50-grit-green.html

Also, if I wet the wall first prior to sanding, will this reduce dust without also reducing my grinder abrasive's efficiency?

 

[Moose-LandTran]

I'd reccomend a Mexican Painter. Very cheap.

 

[Bull]

I'd reccomend a Mexican Painter. Very cheap.

I don't let anyone in my house unless I know them.

And, I don't know any of those guys.

 

[djjsr]

I have a rather large (over 1000 sq ft) old concrete floor that I've been stripping and have tried several methods. Sandblasting or chemical strippers aren't an option for me but I found a "Safe" stripper that works pretty well.

I paint it on with a big brush and cover it with one of those cheap thin plastic disposable dropcloths to keep it from drying out too fast and let it sit overnight. The next day, I pull off the dropcloth and throw it away then spray the stripper with a little water to re-soften it and the paint comes off pretty easy. The residue washes off with water.

The paint I've been stripping is the old enamel floor paint that's been around forever. I've never used this method on latex but it seems like it would work better.

 

[rsanter]

how about one of those sandblasters with the vacume things so it does not make a mess

bob

 

[Bull]

djjsr, is your floor pretty smooth, or textured? Wondering how well that product would work on a very rough surface like the concrete portion of my walls. Maybe I need to get a pic.

 

[Mickey O]

I wonder if an air needle would work?

 

[djjsr]

djjsr, is your floor pretty smooth, or textured? Wondering how well that product would work on a very rough surface like the concrete portion of my walls.

The floor is smooth enough that I can use a putty knife to scrape the stripper/paint. If I had a rough surface, it might be better to leave the stripper dry when you pull off the plastic then use a wire brush to remove it.

Don't know for sure.

 

[Busted_Knuckles]

If youre basement can stand the presence of water, before you spend a fortune on mechanical means or strippers, from a time and money stand point, Id borrow or rent a heated pressure washer, by far going to be the fastest and most thorough way to do it, and probably the least expensive, with probably the best results. The water doesn't care how porous or uneven the surface is, and its not going to leave anything behind. The one bad thing it might do, is over "clean" and remove more material than you wanted, if the brick is unstable. If I was walking in your shoes, that's where I would start. If you basement has contents, and they cant get wet, then that would rule it out, everything will be soaked by the time your done. Sanding brick and concrete mechanically, wow, does that sound like work

Another thought I just had, they do make diamond tipped discs for 5" and maybe 9" grinders. I hired a sub to "polish" a concrete floor, more or less they fly cut several thousands off with what looked like a floor buffer with 25hp electric motor, to give the exposed cut aggregate look, and they edged everything with a hand grinder. One of these hand grinder discs/heads would make short work of removing paint. Sure its overkill, but wouldn't wear out anything like using something for metal cleaning on masonry. Ive cleaned brick before with hot water, but wasnt taking paint off, but I have taken paint off the floor with it, you just get a spot hot with the water, and then cut the angle back and lift it off.

 

[Jononon]

Wondering how well that product would work on a very rough surface like the concrete portion of my walls.

It absorbs into the paint. That's both its advantage and disadvantage, since you need to very effectively clean up afterwards to avoid problems of it leaching out.

Most manufacturers make tester pots, so you could try a small area.

 

[User_Name]

I'm doing a basement bath right now and had to use self leveling compound to even up the floor. Can't poor the stuff over paint so I used a chemical stripper for concrete (Behr from HD). No harsh smell and very effective. Stuff peeled within an hour. Washed the floor using TSP and a firm brush, used newspaper and a wet-vac to clean up. The SLC had no trouble adhering to the concrete - if there were residual paint the pour would have failed.

Might be worth a shot to try it on a test area. You can control the mess a lot easier than with grinding or pressure washing.

 

[Bull]

User Name, do you have the name of the specific product, in case I find that Behr offers several?

 

[User_Name]

It's Behr Concrete & Masonry Paint Stripper, no 962.

Biodegraable and actually smells pleasant.

 

[Motofixxer]

If I was going to use a pressure washer I would hang some plastic for walls to contain the spray. Then use some plastic laying on the floor with some bricks or tubes of sand for weighing down the plastic in a semi-circle. Then use a submersible\utility pump sitting in the puddle that forms from the plastic on the floor pumping to a floor drain etc. All that would probably contain 80% of the water. You would also want to have the pressure washer sitting outside or something, then run the hose in through a window so you don't kill yourself from carbon monoxide.

 

[Bull]

Is a heat gun just a bad idea for this job?

 

[Kelly Burns]

Ok, lets resurrect this thread in a way, since it pretty close to my question.

I've come across a local building I may potentially buy to do a convert it to my garage/living quarters.

Before I go to deep into this, one of the biggest factors (not a deal breaker, but still a major consideration) is the exterior. Its a old brick and mortar building that has been painted, god only know how many time or when, possibly when they make really good paint. There is even flaking all over the building but not very bad and not down to original brick.

Do you think that the fore mentioned method of hot pressure washing would strip it to original brick?

 

[Huffmanb83]

I have to admit I didn't read all replying suggestions, was a lot. So before I got side tracked and forgot. Have you looked into cryo cleaning otherwise known as dryice blasting? It wouldn't solve all the issues but it leaves no residue to mess up new application, leaves no debris of itself so just the **** you wanted off left to clean up, and violent expansion from the sublimation and forced air delivery have made quick work for me in the past without damaging existing surfaces. I've only used it on older paint on concrete, brick, and wood, idk if paint that wasn't easy to get under would be ideal. Then again might not be having this discussion if that were the case.
Came across the process kinda randomly a few years ago, but has definitely been seriously useful in certain projects.
Wire wheeling is definitely more wallet friendly, but tons more requires time and effort. Personally the few hundred to have cleaned was worth allowing me to put my time/effort elsewhere.
Its been a bit, so definitely just a ballpark but $200/hr + market cost of ice.... but goes fast as power washing or sandblasting so covers a lot in that window.
Anyway hope that was at least slightly helpful. Good luck with your project though!

 

[lardy1]

Is soda blasting still a thing?

 

[neophyte]

Is a heat gun just a bad idea for this job?

On masonry?
NO.

 

[neophyte]

Don’t grind or sandblast brick.
It removes the harder outer surface of the brick.

 

[dutchgray]

I wonder if an air needle would work?

It will but a little slow and it will mark the surface.