# muriatic acid



## sidejobs (Mar 24, 2006)

I need to take a sack finish off a foundation wall in order to apply cultured stone (can’t get it to stick to the sack finish). I’m going to use muriatic acid; I’ve never used the stuff before. Do you just brush it on and how long do you have to wait before you can apply the stone?


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## stacker (Jan 31, 2006)

what is a sack finish?if the wall has been painted,you will not get stone to stick by using muriatic acid.you will need to use metal lath.


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## sidejobs (Mar 24, 2006)

Sack finish in our area is a sand mix that is rubbed on to a foundation to make it look finished (hides panel mark and tie marks). It looks like paint on sand finish but the color of cement. I’m not sure as to the mix or application. The way I get a sacked look is to apply thorite with a rubber float.


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## BigJon3475 (Oct 15, 2007)

If you do decide to use it make sure you use all protective equipment that stuff is nasty when it hits. It'll make you gag if your anywhere near it.


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## sidejobs (Mar 24, 2006)

I’ve got a good full face respirator and neoprene gloves.


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## bobcaygeonjon (Aug 30, 2007)

sidejobs said:


> I need to take a sack finish off a foundation wall in order to apply cultured stone (can’t get it to stick to the sack finish). I’m going to use muriatic acid; I’ve never used the stuff before. Do you just brush it on and how long do you have to wait before you can apply the stone?


It sounds like you are talking about a thin parging. If it not painted then the stone will not stick. Do not use acid to remove you will need gallons and gallons and may damage the foundation. Acid is for removing stains only. 
Try metal lath instead. Safer and easier.


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## sidejobs (Mar 24, 2006)

thanks I'll use lathe


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## sidejobs (Mar 24, 2006)

Wasn’t aware what parging was with a quick look on line I’m fairly sure it’s not parging.


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## Tscarborough (Feb 25, 2006)

It must have an additional coating on it if it is any type of cementious parging material, be it Thoroseal, sand mix, or job mix. Adheered veneer will suck onto any of those products so fast and tight that you better do your adjustments quick.

If it won't stick, it may be your mix (probably too wet), or there may be a clear sealer or paint on it. A photo would help.


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## sidejobs (Mar 24, 2006)

I still don’t know what was on there. Took muriatic acid and painted on a coat, it bubbled a little. After rinsing there was a coat that looked like Laminate glue that was real heavy and to the almost tacky state. If I work it real hard it would ball up. After another coat of muriatic acid it was still there, but after an hour with a grinder with a wire wheel it is now all gone. I’ll try to stick the stone tomorrow. Broke through the coating looked like sand and cement and about 3/16” thick. To late for pictures and probably would have been hard to see. Thank for the responses


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## Tscarborough (Feb 25, 2006)

So it was coated with some unknown goo. If you got that off down to cementious coating, you should have no problems. The rule is 80% clean. That means in a 1 inch square area 80% is totally clean and in a 10 square foot area 80% is clean. 80% of any given area has to give good adhesion. That is worst case.


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## Tmrrptr (Mar 22, 2007)

Better to apply muriatic acid in solution with a hudson type pump up sprayer. Use eye and skin protection. nasty stuff!
Rinse well.

Goo must have been a latex bonding agent.
Probably could have went right over the "sack finish."
r


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## Chris Johnson (Apr 19, 2007)

Sounds like acrylic stucco base coat to me if it's got the goo, good luck trying to get that stuff off. The lathe over the top solution sounds easier to me.


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## chris n (Oct 14, 2003)

Don't know where you are working but muratic acid is very toxic to tree roots also( besides yourself) trust me,I found out the hard way


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## sidejobs (Mar 24, 2006)

I installed lath and a scratch coat of type N mortar and I’m still having problems. I’ve tried wet runny mortar, drier mortar, mortar additives, wetting the stones, wetting the 
Scratch coat and on and on. Don’t know what’s going on, the first 70 square feet went fine. So for the last 20 feet I called a local mason and for 300 bucks he’ll finish the last 20 feet for us.


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