"HeyBub" wrote in message
...
Robert Macy wrote:
On May 26, 4:08 pm, " wrote:
My bathtub has a stain in it that is impossible to remove so far.
Here
is a picture of
it:http://www.flickr.com/photos/5423000...7629878927850/.

What should I use to remove the stain? I tried bleach and it does not
work. It feels rather rough and even powderly at the stained area.

Thanks

Whink, mild HF acid


HF? OMG! NEVER!

Even the tiniest amount of the most diluted Hydrofluoric acid is a calcium
blocker and will stop your heart. The treatment for HF poisoning is
hit-and-miss.

I think you meant HCl or hydrochloric acid, sometimes called Muriatic
acid. Be prepared for fumes and set up some good ventilation.


Believe it or not, there is a product on the market that contains HF for use
in rust removal. I can not remember the name but it is even sold in my
local Ace Hardware. The first time I heard of it, I demanded the fellow who
told me about it bring in the bottle because I could not believe it. Sure
enough, the primary active ingredient was HF. He took it away from his
mother who was about to use it on a kitchen oven.
The scary thing to me about HF is that the deadly effects are not immediate
when the skin is exposed to a tiny amount. The pain gets worse until it is
unbearable. By that time, the HF has made it to the bone and its calcium
channel blocking effects can occur shortly thereafter.