MA dilution for cleaning scale

[trivetman]

Time to clean some scale buildup on the coping and above the waterline. I know ive read to use diluted MA but the ratio of dilution is never specified. Anybody know what works best?

Is it worth it to try white vinegar first just because itll be less nasty to handle? Is it iust not strong enough?

Pic of the worst spot attached.

 

[mgtfp]

I don't know the best ratio for that purpose, but whatever you do, remember the golden rule for acid handling: Always add acid to water, never add water to avoid.

 

[Toxophilite]

My rule is that to MA acid clean anything is the method of last resort since it is going to affect all in many cases. When at the decision point, I start with the mildest I think of to work since there is no "ratio" for all situations. My attack after trying some mild off the shelf acid cleaner would be maybe 10 parts water to 1 part MA, which is still a pretty strong stone wash ratio. I would manually remove as much as can first to limit acid clean time.

 

[trivetman]

Well, I went stronger . I had some 2:1 already on hand and tested out a small spot and it seemed to do no harm so I went with it.

Made pretty quick work of it though it is tedious doing small spots on the entire circumference. The MA, a small metal pick and a nylon brush do the trick with a thorough rinsing after each grout line. There has been still a bit of calcium film left over after I am done, particularly in the grout but thats ok.

Heres a shot of that worst spot after a few minutes of work.