HI,

I have been working on cleaning my slate floor for a while now. Back a
month or two ago you guy gave me some cleaning suggestions for cleaning the
tile. After trying the suggestion along with other things, I finally got
the coating off the floor. Below if the description of the grout problem if
any of you have the time or experiance to lend some suggestions. Thank you
in advance, J

I have good clear photos of the tile floor with the grout that I can e-mail
to you if it would help.

The grout rapidly asorbs water.

The slate floor was put into the home in 1963. Sometime over the years,
likely about 20 years ago, someone aplied some type of coating to the floor,
I believe it was polyurethane. The cloating was partially worn off, and
looked horriable. After trying to clean the floor with a number of
commercial strippers, solvents, and manual abrasion I ended up using a
methyl chloride based stripper to clean the floor. The coating came clean
with the stripper and a lot of scrubbing. I was left with the grout the way
it looks in the photos. It is smooth to the touch and does not appear to
have any of the polyurethane coating still on it.

Now that the polyurethane coating is gone I have tried to clean the grout a
number of ways. I have used: abrasion with scouring powder, chlorine
bleach, oxygen bleach, a commercial cleaner that is alkaline based, paint
thinner, alcohol, detergent, vinigar, and lacquer thinner. I have not tried
a more acidic (muratic acid based) cleaner, but I am not optimistic it will
work since everything else has failed to clean it, including the vinigar.

If you have access to oxalic acid I would try that.
If you can find some concentrated hydrogen peroxide say 20% or so it
might also work.
Some stains however are forever.
j wrote:
HI,

I have been working on cleaning my slate floor for a while now. Back a
month or two ago you guy gave me some cleaning suggestions for cleaning the
tile. After trying the suggestion along with other things, I finally got
the coating off the floor. Below if the description of the grout problem if
any of you have the time or experiance to lend some suggestions. Thank you
in advance, J

I have good clear photos of the tile floor with the grout that I can e-mail
to you if it would help.

The grout rapidly asorbs water.

The slate floor was put into the home in 1963. Sometime over the years,
likely about 20 years ago, someone aplied some type of coating to the floor,
I believe it was polyurethane. The cloating was partially worn off, and
looked horriable. After trying to clean the floor with a number of
commercial strippers, solvents, and manual abrasion I ended up using a
methyl chloride based stripper to clean the floor. The coating came clean
with the stripper and a lot of scrubbing. I was left with the grout the way
it looks in the photos. It is smooth to the touch and does not appear to
have any of the polyurethane coating still on it.

Now that the polyurethane coating is gone I have tried to clean the grout a
number of ways. I have used: abrasion with scouring powder, chlorine
bleach, oxygen bleach, a commercial cleaner that is alkaline based, paint
thinner, alcohol, detergent, vinigar, and lacquer thinner. I have not tried
a more acidic (muratic acid based) cleaner, but I am not optimistic it will
work since everything else has failed to clean it, including the vinigar.