In a message dated 6/14/01 9:35:41 AM Central Daylight Time, [log in to unmask]
writes:

An (Irish) contractor I know swore by muriatic acid. "'Clean it up real nice,
it will," he said.

It does clean up real nice. It also continues to eat away the lime and any
calcites in the masonry after it is used as well as etch stuff like metal and
glass. I never knew what it was particularly or that it was so terribly
dangerous for the 5 or so years that I worked with it several times a week.
Seems if you are not so clean of a mason's helper pointing up newly laid
bluestone flooring that you get to spend a lot of extra time cleaning up your
mess. It would have helped if the mason had any inkling of how to explain
himself beyond grunts. I got fairly used to acid burns, as we tended to wear
cheap cloth gloves, which would soak in the acid, and to use it undiluted.
Leaving a shovel, or a trowel, in a bucket of muriatic overnight does wonders
to remove caked on mortar. Getting it in the eyes is not particularly fun and
you have to be cautious not to breath the vapors. Proprietary cleaning
chemicals have buffers in them that assist in reducing the damage to the
masonry and slightly reduce the risk of worker injury -- they aer also used
in dilution. They still need to be handled with proper personal protection,
knowledge as to what they are (MSDS sheets... I'm sure the Irish mason reads
his MSDS sheets), and proper technique.

> So I went to the local hardware store, and was read the riot act by the
> owner (a friend). "Do you know how dangerous this stuff is? I don't sell
> this to just anyone, you know," she said. I bought it, read the directions,
> and chickened out. Too dangerous for me, that's for sure. I'm amazed you
>

Sounds like a good friend. Reminds me of the time I bought the 140 proof
vodka -- for medicinal purposes.

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