Oxalic or Phophoric Acid for Bathtub

[Jen]

Hi,

My bathtub is cast iron and 62 years old. The previous owner was
elderly and wasn't able to clean very well. It has quite a bit of
calcium, lime, soap scum and rust deposits. From reading this group
and various other sources I know I need to clean it with acid I'm just
not sure which would be better - phophoric or oxalic acid (aka wood
bleach). I know oxalic is poisonous and phosphoric is little easier to
deal with but I want the best results possible. Refinishers do an acid
cleaning before they refinish a tub. Anyone know what they use? I
would appreciate any info you may have regarding acid use for cleaning
a tub with these kinds of stains.

Also, after cleaning does it make any sense to use a polishing
compound to buff out the tub? I'd like to restore whatever luster or
life it has left in it and I don't want to resurface. I was thinking
of a buffing compound such as what is used on cars after they are
newly painted. I believe this has a componenet similar to a very very
fine grit wet/dry sand paper. Aren't tub paints similar to what are
or used to be used on cars?

Any thoughts would be greatly appreciated.

Please e-mail direct to jenetic@sbcglobal.net

Thanks very much.

[Gary V. Deutschmann, Sr.]

Hi Jen

Muriatic Acid 50% solution or 15 degree baume (store bought is usually
30 degree baume so cut it in half with water)
But NOTE: This will also etch the porcelain a little.

Refinishers use Sulphuric Acid to clean ceramics before refinishing.
Not something you want to mess with.

TTUL
Gary

[sijka]

I agree--I learned that from my plumber father!!

Sijka

"Gary V. Deutschmann, Sr." <raiar@bbs.galilei.com.nospam> wrote in message
news:403e1dc9.242546171@news.galilei.com...
> Hi Jen
>
> Muriatic Acid 50% solution or 15 degree baume (store bought is usually
> 30 degree baume so cut it in half with water)
> But NOTE: This will also etch the porcelain a little.
>
> Refinishers use Sulphuric Acid to clean ceramics before refinishing.
> Not something you want to mess with.
>
> TTUL
> Gary
>
>