Acid Wash Concentration

[DBissett]

I'm talking to pool remodelers about replastering the pool next month (thinking quartz) and discussed not doing an acid wash with one. He said the acid wash uses a very low acid concentration and wouldn't hurt the plaster. I've never seen this mentioned here and was wondering if the acid wash concentration actually might vary. Does every company use the same or not? What concentration would be "safe" or recommended if this is done? I plan to narrow my choice of company based on estimates and then filter by how they deal with the acid wash question and possibly do a bicarb startup, or at least a water wash if possible. However, the other response I'm getting from installers is that deviating from normal startup procedures might invalidate the plaster warranty. How best to respond to this? Thanks.

 

[mgtfp]

I tend to think that if an acid wash shows an effect, then it will have taken some plaster away. The only recommendation here is that acid washes are usually not recommended. In most cases you are better of putting up with some optical imperfections.

In many cases (like metal staining) there are other options to explore before considering an acid wash. What is supposed to get fixed with an acid wash? You are also mentioning replastering. Why acid wash if the pool is getting replastered anyway?

 

[DBissett]

I was talking about the acid wash that's done as the last step following the plaster.

 

[Bperry]

I was talking about the acid wash that's done as the last step following the plaster.

The acid removes the top layer of plaster cream and exposes the aggregate (quartz). If you don’t want the quartz exposed, I might suggest a generic plaster instead as it’ll be cheaper. In reality, it’ll be fine.

By definition, acid washing “harms” the plaster. That’s the whole point of it as it dissolves a thin layer of the plaster and exposes what’s underneath. That’s why TFP discourages acid washing to just clean existing plaster.

If you’re referring to diamondbrite, their installation guide referred to a water washing process instead of an acid wash but describes it as requiring more skill than acid washing. I suspect that means its costs more too.

 

[AQUA~HOLICS]

Most plaster companies will have a specific person to do the wash the fallowing day and no set formula is written.
Each plaster finish is different and the amount of acid needed to accomplish the best results is typically determined at the job site once the plaster is inspected.

 

[ajw22]

Power sanding using diamond pads is preferable to an acid wash but is more labor intensive and expensive.

Acid washing is the cheap way of smoothing out a plaster finish.