Cleaning red brick without burning

[m777]

I used a acid wash that was way too strong on a fireplace and it turned the mortar joints a nasty yellow color. Sorry, I'm new to this.
Hard to get that classic red look back once the face of the brick is etched by chemicals. But I found that a good soak with plain water before and after scrubbing is the best way to prevent staining. I'll test some more when I have the same projects. But anyone here done this? What iis your go to ratio for muriatic acid or have you switched to safer cleaners?

 

[speed fighter]

@m777 From experience, the key to acid washing is definitely the pre-soak with plain water. If the brick is dry it will soak the acid right into the pores and that is when the burning and staining happens. I always keep a hose running and keep the wall dripping wet before any chemical touches the masonry.

 

[El VMX]

No. I moved away from muriatic acid years ago and started using a dedicated masonry cleaner. It's sure is a bit more expensive but it has buffers in it that prevent the yellowing and the green vanadic staining. And it is much safer for the vegetation around the house too and for myself. It's such as nasty chemical if ou ask me.

 

[oliverjack]

I used a acid wash that was way too strong on a fireplace and it turned the mortar joints a nasty yellow color. Sorry, I'm new to this.
Hard to get that classic red look back once the face of the brick is etched by chemicals. But I found that a good soak with plain water before and after scrubbing is the best way to prevent staining. I'll test some more when I have the same projects. But anyone here done this? What iis your go to ratio for muriatic acid or have you switched to safer cleaners?

I saw a guy try to clean a wall with a pressure washer and acid at the same time and he ruined the mortar. The pressure blew the acid deep into the joints and it continued to eat the cement for weeks. A stiff scrub brush and a garden hose is still the best way to control the process. So I don;t really recommend strong acid.

 

[larcos.ibiza]

Question, does the yellow staining ever go away on its own over time? I had a small spot on a job last year that looked a bit off but the owner never complained. I wonder if the sun and the rain eventually neutralize the acid and wash the residue away.

 

[redtarget]

Try a mild solution of white vinegar can sometimes take off light mortar haze without the risk of burning. It takes a bit more scrubbing and elbow grease but it gives me a lot of peace of mind on those expensive custom brick jobs. That is if you have the extra time to do it.