My first approach would be diluting some phosphoric acid (etchant for
automotive primer, metal-prep).
Mix in a Labeled trigger spray bottle, and wet the residue, checking
adhesion and re-wetting as needed.

I believe the muriatic would work, but it's a much nastier product to have
around machines.

Some of those tile cleaners like lime-away (can't recall the one with 3
letters), which contain phosphoric acid may be effective, too.

When the residue begins to release, a stiff bristle brush would likely
remove most of it without stripping off the epoxy? case paint.

--
WB
..........


"Ed Huntress" wrote in message
...
On Sat, 10 Dec 2011 18:39:40 -0600, Ignoramus20184
wrote:

I have a couple of those

http://igor.chudov.com/misc/ebay/tmp/J-G-Porter/133.JPG

They have white concrete on them, some solidly stuck. How can I remove
it safely to restore the good looks. Thanks


Ugh. If you're brave, muriatic acid should do it.

--
Ed Huntress