Can anyone help me with the proper procedure for buffing out a nitrocellulose lacquer finish? I'm interested in using rottenstone, pumice and oil.
What is the proper sequence and technique?
Use a sanding block, not the flat of your hand.
Then mix up a slurry of pumice. Then you can finish off with rottenstone. Rottenstone is finer than pumice.
When you wet-sand, use a squeegee to check your progress, and check that progress often.
You can use a sanding lubricant made from Murphy's Oil Soap diluted with 75 percent water or more. Or you can use mineral spirits, mineral oil, naptha, or combinations of any or all of those three petroleum distillates.
Do you load the carpet up with lubricant or polishing compound? Do you back it against a flat block? And so on...
I used a semi-gloss, but I want maybe just a little more sheen. I was curious about using pumice, rottenstone and paraffin oil, and got a response, but am still unclear as to how to apply the "slurry." Do I use the fine grit sandpaper or a rag?
You can rub this abrasive slurry with a rag. But even better than that is to use a large, flat piece of hard felt. Dip the felt in the slurry (or pour some on your surface) and rub in very straight lines. That means you should not arc your rubbing stroke like a rainbow or windshield wiper.
Another method of application is a rubbing brush. I have only heard about this, as this is an old-school method and I had to learn everything on my own. Anyway, the brush resembles a shoeshine brush. I think that these are available online at Ron Ashbey's Liberon.com website. He can also give you tech support on using this method of applying pumice and rottenstone.
It is my understanding that factories are still using pumice and rottenstone in their cutting sequences to achieve certain sheens (to be more precise it is the "look" of certain sheens that they are using them to achieve). But I think that they are using these abrasive materials with pneumatic dual-pad rubbing machines like the ones made by National Detroit and Stuhr (Cooper Power Tools).
It is hard to replicate by hand what these pneumatic machines can do to a finish. Difficult, but not impossible.
I hope that explains a little more. Now let's wait and learn about the artful use of carpeting in the rubbing out of a finish.
About 25 years ago we started spraying all the final sheens, and the tops held up much better -- no re-calls. What also helped is that we added a slip additive to the last coat so things would slide and not scratch the finish as easily. Now the only time we rub anything out is if it was that way when it came in.
As for the carpet, yes, it is the stuff we walk on. Just get some good, short-nap commercial-grade wool carpet. Cut it to about 4 by 10 inches, then trim back the backer, because even a thread from it will ruin a rub-out if it works its way underneath.
Soak the carpet to get it wet in some soapy (woollube) water, sprinkle a little pumice/etc. on it and rub away in nice, long, straight strokes. You can also place this on a Sundstrand inline sander to do a nice fast rub.