Help remove silicone caulk from brick

[spotco2]

Bought an old brick building that someone had glued lattice all over the front with silicone caulk.

Anyone have a sure fire way to remove the silicone caulk from the brick without damaging the brick?

So far we have tried razor blades (it only takes off the top layer), Goof Off, Acetone, heat gun, propane torch and wire brush on a drill and we've not done much more than make a mess of it. Any help is appreciated.

 

[bluedog225]

Ugh. Doomed. Maybe a big grinder and just take off the top 1/8”. What a mess. Sorry.

edit-maybe try freezing it?

 

[Shiftless]

It sounds to me like you’ve tried everything short of sandblasting or like bluedog said, a big grinder with a stone cup wheel.
As much as I hate painting brick, If you have scraped it down smooth, you might consider color matching the brick and painting it. It might not look as bad if you just carefully paint the bricks and not the mortar joints.

Based on the one photo you posted, I bet there are plenty of other projects there to occupy your time and money.

Many years ago, a friend bought a commercial storefront kind of building that had been a store, then a laundromat and then after massive unrepaired water damage happened, a dog kennel that moved out due to a roof collapse. If I remember right, she paid only a few hundred bucks.

 

[duneslider]

You need a silicone digester LINK

 

[gizardlizard]

Pressure washer with rotating turbo nozzle

 

[rlitman]

You need a silicone digester LINK

+1 This is where I'd start. Brush on a chemical that dissolves the silicone. Give it some time to get it to release the bond with the brick.

Pressure washer with rotating turbo nozzle

And once the silicone is digested, pressure wash it off. Worst case, you may need to resort to a wire brush or even abrasive blasting, but hopefully not.

 

[rust in the eye]

I've had success removing excess mortar using a needle scaler. Might work for this too.

 

[spotco2]

You need a silicone digester LINK

I was not aware this existed! I'll start researching it.

Thanks for all of the ideas.

 

[rlitman]

I was not aware this existed! I'll start researching it.

Thanks for all of the ideas.

I want to say I found this stuff in either HD or Lowes maybe 20 years ago on the paint stripper shelf. The one I used was a cream with a mayonnaise like consistency you could brush on thick onto the silicone. After some time, the silicone turned crumbely and let go of the bath tub and tile I tried it on, and made the job of scraping it off much easier. It did not dissolve the silicone (at least for me) or turn it into a gooey mess, but it did break it down enough to get it to come off easily.

 

[Pen & Wrench]

You might try Goof Off Graffiti remover in a spray can, it has worked on some nasty stuff for me.

 

[nadogail]

You can use “Elbow Grease”. My mother told me that with enough of it anything is possible.

 

[RoscoTom]

You need a special vacuum cleaner for that silicone.

It's called a caulk sucker.

 

[ycgoat]

I would scrape the bulk of it off first, then use the chemical dissolvers, then clean the entire wall like it was a new wall by soaking with water and acid and scrubbing with a brick before rinsing it clean.

 

[Old Man Roger]

You need a silicone digester LINK

Without knowing anything like this existed, it was my first thought. My second thought was wet sand blasting.

 

[bbrz]

I watched a tile setter remove silicone from a water closet set that had been caulked to a floor. The flooring was a brick face type of tile. He used a small steam machine and soft bristle brush. Came right up.

 

[Old Man Roger]

I watched a tile setter remove silicone from a water closet set that had been caulked to a floor. The flooring was a brick face type of tile. He used a small steam machine and soft bristle brush. Came right up.

Probably not as porous as a brick.

 

[Hilltopmasonry]

Pressure washer with rotating turbo nozzle

Be very careful with the turbo nozzle, because it will damage softer brick

 

[Leaflessshadetree]

Put a sign up asking people to refrain from peeling rubber from the wall.

 

[spotco2]

I had a chance to play a little with it this afternoon. I put an edge on an old multitool blade with a file and that did a much better job than just a razor blade for cutting the bulk off. The only silicone digester I can find is about $600 for a 5 gallon bucket and it's hard to pull the trigger on that just yet. I've got some time to play with it so I'll try some other chemicals first. Thanks again.

 

[kyrbz]

I like your building. I've lived in an old brick building for 30+ years. I've had surprisingly good luck removing thick adhesives and paint off of block walls with a Harbor Freight surface conditioning tool. They usually have them on sale for $100 and it comes with 3 abrasive drums. If you tried the surface conditioning tool, I'd scrape as much as possible the way you described you're doing, and then use the surface conditioner for the final clean? The only drum I used were the coarse grey ones and I went through 7 drums cleaning 2 - 8'x10' walls. I normally use these surface conditioning tools for metal work but I was surprised how well it cleaned block without damaging the block.

 

[Fav Onefour]

I'm impressed how well the H.F. surface conditioning tool cleans up that stuff.

I've used angle grinders and wire wheels on quite a few concrete clean up jobs. It's not exactly the greatest combo for truly clean end result. Biggest issues are heat with some adhesives and burnishing.

@spotco2 , It might be worth doing a quick test with a simple angle grinder to see how much it leaves.

Anyone notice the typical DIY caulk gun pattern? I see that stuff all the time. The pattern is super fancy and thorough at the easy to reach levels. After the work was harder, they went to "whatever works" pattern. I see the same thing with nails and fasteners. Easy to reach means plenty, hard to reach gets "whatever works".

I'm usually a little leery on those projects. It generally means there are other hidden surprises.

 

[BlindViper]

I had a chance to play a little with it this afternoon. I put an edge on an old multitool blade with a file and that did a much better job than just a razor blade for cutting the bulk off. The only silicone digester I can find is about $600 for a 5 gallon bucket and it's hard to pull the trigger on that just yet. I've got some time to play with it so I'll try some other chemicals first. Thanks again.

maybe you can contact the manufacture and ask for a sample to try out?

 

[BlindViper]

One issue with using a grinder or like tool is if you want to paint/repaint is nothing sticks to silicone but silicone. It leaves a residue that will cause the paint to just "run away" from the silicone.

 

[Fav Onefour]

One issue with using a grinder or like tool is if you want to paint/repaint is nothing sticks to silicone but silicone. It leaves a residue that will cause the paint to just "run away" from the silicone.

I completely agree. The grinder trick in my experience is only one step to getting a thinner layer.
The silicone digester sounds interesting. I've never tried the stuff.