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[drnihili]

So, what polish should we be using on the leather buffing wheel?  Up to this stage, out of a surfeit of laziness, we've been snitching polish from the tumbler.  I'm assuming that's not ideal.  What do those in the know use?

[lithicbeads]

Most folks use cerium oxide. You use a thin slurry applied with a small brush. Atmospheric dust needs to stay off the polish pad , brush and slurry container. The pad gets charged to an extent through application and use. Do not mix polishes. You spritz the revolving pad that has been charged and polish until the pad dries. You will feel a strong pull as the pad dries and that is when the polishing happens. Minimal spritz and resume polishing. Use al the pad and try not to soak the pad or use too much polish. The quality of cerium varies wildly. Send me your address in a pm and I will send you some. Hold on tight as the stone will try to jump out of your hand when the polishing gets going.

[PhilNM]

I use tin oxide. Seems to work best for all different types of stones.

Here's a guide I use.

INTRODUCTION
1. Many stones polish equally well with several buff and polishing compound combinations. A very hard gem can be polished by a much softer polish powder. Only one polishing agent should be used on a buff.
2. Polishing does not remove any material from the surface. If scratches develop, the stone must be re-sanded.
3. It is impossible to obtain a high glossy finish on very soft materials, especially if they tend to be slightly porous, fibrous, or granular. As a last resort with this type of material, a finish gloss can be given by the use of spray varnish.

BUFFS
Canvas: Canvas is useful when polishing heat-sensitive stones because it develops very little friction.
Muslin: Muslin buffs are recommended for soft stones and gems that are heat-sensitive.
Leather: Leather is a versatile buffing material that is both efficient and economical. Leather generates heat,
but not as much as felt.
Felt: Felt is useful for polishing glass and stones of even texture. It is not recommended for gemstones that
under cut. Friction on felt generates heat rapidly.
Phenolic: Phenolic tools or phenolic lap disc (cab laps) are useful when impregnated with diamond grit.14,000
Micron (pre-polish) or 50,000 Micron (polish) diamond compound can be applied to the surface of
the gemstone and worked with a phenolic carving tool. It can also be applied to the surface of a phenolic lap
disc and worked with the gemstone mounted at the end of a dop stick. The diamond will charge the phenolic
plate making smoothing and polishing easier.

POLISHING COMPOUNDS
Cerium Oxide: Covington cerium oxide will polish at a faster rate than conventional polishing compounds
and produce a superior optical lens surface with no staining or caking. Because it will polish faster, a lower
concentration can be used. It is recommended for use on leather, felt, polyurethane foams, and thermoplastic
polishing pads. It is a favored polish for quartz type minerals and other gemstone types. It is not recommended for gemstones that will under cut.
Linde “A”: A .3 micron aluminum powder that is carefully graded for uniformity of grain size. It is excellent for polishing stones that will under cut. Excellent for hard to polish stones.
Chromium Oxide: Chromium oxide is a hard polishing agent. It is green in color and stains badly. It is useful for polishing jade and stones that will under cut.
Tin Oxide: Tin oxide is an excellent general-purpose polish. It is used to provide a final high gloss finish.
Diamond: Diamond grit is the most efficient polishing medium. It is especially useful for polishing difficultto-
polish stones.

[drnihili]

Thanks, Frank and Phil.

So, we've been using "Lortone polishing charge".  No clue what's in it, and the label is entirely unhelpful.  Of course we also have no idea what was used before.  Given Frank's advice to not mix polishes, it seems we'll also be in need of of new material for the buffing wheel.  Leather is what's on there now, and seems to be a versatile option per Phil's list.  I'm assuming I shouldn't just slap a piece of tanned elk on there, so what counts as appropriate leather for buffing, or should I be looking at just getting a premade buffing wheel?

[PhilNM]

Elk is just fine. Actually preferred by many.   You can also wash the old one.

[MrsWTownsend]

i use cerium oxide for most materials.  People suggest Zam for turquoise and softer materials.

I suggest keeping separate leather pads for the different polishing compounds you use- you can keep each in a ziplock so they don't get cross contaminated.  I do the same thing with my buffing wheels; keep them in a zip lock with each polishing compound to prevent cross contamination and so I don't forget which one has what on it.

[lithicbeads]

If you wash and scrape the pad thoroughly as it runs you can get it clean enough from uncontaminated polishes. Spray and scrape. It will take a while to dry. You can try to rough it up a bit at that point if it seems very slick. Scraping gently will do that. That polish is basically junk.

[adovbs]

If you wash and scrape the pad thoroughly as it runs you can get it clean enough from uncontaminated polishes. Spray and scrape. It will take a while to dry. You can try to rough it up a bit at that point if it seems very slick. Scraping gently will do that.

Thanks!  It could probably use a good cleaning and roughing up. I'll try to do that this week some time.

That polish is basically junk.

Yeah, we figured so, but... it's what we had on hand.  I've used it on the four cabs I've done so far, and even a noob like me was starting to suspect that maybe it wasn't the best polish for the job. 

[adovbs]

i use cerium oxide for most materials.  People suggest Zam for turquoise and softer materials.

I suggest keeping separate leather pads for the different polishing compounds you use- you can keep each in a ziplock so they don't get cross contaminated.

Thanks for the tips!  We're going to try some better polish - I'll have to order it this week - and we'll also see what we can find to make another polishing pad or two for the polish wheel.  We'll use your idea of keeping them in labeled ziplocks to prevent cross contamination.

[drnihili]

We've got plenty of leather lying around, including most of an elk hide.  I just have to locate it all and see if we have one with a soft enough tan.

[MrsWTownsend]

I learned that practice from the buffing pads I use for buffing out silver, because I use 4 different polishing compounds that have different grits in them.  I don't want my white compound getting red rouge in it, that would cause unwanted scratches in my final polish.

Some compounds like Zam are bound together with an oil base (I  think) and the cerium oxide I use is a powder.  I am not sure that getting both on one pad would be a huge hindrance at the final polish stage, because they are both designed for that stage of finish, but it seems like a good habit to get into in the big picture.

Another thing to take into consideration is cleaning your wheels in between material types- you can run the wheels and use a wet cloth, just press it against the wheels to help get some of the previous particles of material off.  This makes a big difference when working with materials like jasper and then switching to something like obsidian, where every little particle can leave a new scratch to buff out.

[PhilNM]

ZAM is chrome oxide in a wax base. And as a powder the green is horrible to get off!

[MrsWTownsend]

ZAM is cerium oxide in a wax base. And as a powder the green is horrible to get off!

Well there you have it!  Must be the wax that makes a difference on turquoise and such. 

What green are you referring to?

[PhilNM]

My bad,     I was thinking chromium oxide. nasty stuff. The pros I know use sapphire powder as a final buff after the ZAM, and they get gorgeous results.  They also have slowed down their buff units to 800 rpm. 

[MrsWTownsend]

I am glad I have never tried it then.

Sapphire powder...  Hmmm....  I don't do much turquoise but you have piqued my curiosity.   :D

[iceopals]

Linde A is more than likely how you will find the sapphire powder.  I have used it for years, and prefer it to cerium oxide for cabs.  I do use the cerium for carving though.  Huh, interesting.  I never really thought about what it might be that I like for each application, or why, just like using them like that.

[MrsWTownsend]

Thanks!

I found a place with every polishing compound under the sun listed but they are expensive...  It says Linde A is aluminum oxide or 99% pure Alumina, according to another website.  http://www.gravescompany.com/polishin.htm

Cheaper here
http://www.johnsonbrotherslapidary.com/Sapphire_Polishing_Powder_-_Linde_A_-_03_micron.html

[iceopals]

Interesting!   I found this also---
Sapphire Powder is 99.9% pure 0.03 micron aluminum oxide.  It is "A" grade, the best you can get, and is known to some under the old brand name 'Linde A.'

Sapphire Powder is used for polishing tourmaline, beryl, garnet, topaz, peridot, danburite, etc.  It has a hardness of Mohs 9, and is therefore most useful for polishing very hard and/or difficult materials (but not corundum).

Do NOT ask me why this is!!!   I just always had the understanding that Linde A was sapphire powder, now maybe that is just an accepted terminology?

[MrsWTownsend]

Well it said it was commonly used for polishing faceted stones, maybe originally, the bulk of it's use was for Sapphires and that is how it got its name.