Sherry Lee

SGF, Supreme Grumble Framer
Jun 25, 2002
Phoenix, Az.
Some Hitchhiker folks have asking where to find rottenstone = "hardware stores" was the most common answer.

I want to know what framers (or others) use it for?
Rottenstone (red) is 2,000 grit for polishing.
Rottenstone (white) is 6,000 grit. Also called Talc.

Pumicstone (grey or gray) which most people confuse with rottenstone is 900-1,200 grit depending on how it is ground.

Now that is what it is. As to the use; it is for "Polishing" a finish on a frame.

Shellac or Lacquer when shot (sprayed) ends up with a texture of 180 grit, which is very satin to mat. Polymer dispersing agents are put in to cause the finish to "flow" which leaves the finish closer to 400 grit or shiney.

But, it isn't very smooth. The perfect finish is the smoothness of 4-6,000 grit, but with a sheen more akin to waxed 1,200 grit (satin).

The way to get that with gold leaf is to 1) water guild and polish your gesso and boul. Then polish the leaf into the boul. Or 2) guild which ever way you want, then polish out the finish coats of shellac or lacquer.

Along the way, with the carnuba wax and the pumic or rottenstone, the cracks, corner, nooks and crannies get a layer of wax & stone which is similar to the generations of polishing wax and dust that gives the old frames that "Patina". So to simulate age, framemasters use final coats of wax and stone.
That is a wealth of information! Thanks for that in-depth explanation Baer. You must be one of those MCPF++++'ers!!

Thanks Judy - I hope those who are looking for it see your comment.

And Framanista - that is good info for my artists (in case they don't already know).
A combination of alcohol, casein, and rottenstone
can be used to create a dust wash that also tones
the gold. It should be kept thin and light on the
rotten stone.

Originally posted by Framing Goddess:
There is a homemade glass cleaner formula that has rottenstone as one of its ingredients. Is it in one of Paul Frederick's books, perhaps?

Here's a link to the thread of just a few weeks ago about Rottenstone as a glass cleaner. Also an earlier discussion about using Rottenstone as a cleaner.

Did a search on Rottenstone and quite a few threads popped out. (Gotta get my needle and thread out and fix that!)
Hugh, if you're still there, why the addition of alcohol to the casien, rottenstone mix? Seems like it might harm previous layers? Is it just a few drops?
The recipe for glass cleaner is:
Glass Cleaner

4 oz Denatured Alcohol (or Methanol)

16 oz Water

1 tsp. Rottenstone

½ tsp Dishwashing Liquid
Like Rick, I favor buying a prepared glass cleaner. Yes, Tru Vue's Premium Clean and Sparkle are the same product and both are great choices. Still, my favorite is Ultra Lite from Frame Specialties, because it's concentrated (8 oz. makes more than a gallon), chemically non-reactive with everything in the framing package, and works on all kinds of glazing.

As far as I know, none of these glass cleaning products contains rottenstone or any other sort of abrasive.
We all seem to have our own fav glass cleaners. I have use Bohle for about 37 years.