Formula for polishing and buffing compounds

A. Shamim: Calcined kaolin.

A. Hi cousin Vinod. Please don't invest money based on internet advice from strangers :-)
Please start by at least reading the "Buffing & Polishing" and "Buffing Wheels & Equipment" chapters in the Metal Finishing Guidebook so you have an understanding of how to select abrasive materials and different abrasive sizes, and what the characteristics are of stainless steel and aluminum which will help guide those choices. Your customers are not likely to be able to polish & buff with a single type of bar, but will probably need a number of different grit sizes.

Because buffing compound bars are a commercial product rather than a home-brew affair, you won't see much about their exact composition in technical articles or on the internet ... but I believe you will be able to find some info in expired patents. Best of luck.

A. Not sure what you are looking for here. I suspect no one will give you the actual formulation of a buffing compound; however, it shouldn't be that hard either. The primary ingredient is normally an extremely fine aluminum oxide powder blended in some form of fatty compound. Compounds are formulated to work in or at a certain temperature range.

A. Hi Reshmi. We added your inquiry to this thread about the composition of buffing compound. Marketing studies about current & future demand for product lines like this are generally offered in the $50,000 USD range, so I doubt that you'll get any actionable info from your posting; but here it is, and best of luck.

Regards,

A. Hi Abhinav. Buffing compounds do have "shelf lives", probably mostly related to evaporation of solvents from the binders. The life after the package is opened is much shorter than while the packaging is still sealed.

What is really at "the base of it" is this: buffing and polishing is not something you can practically do with a single bar of compound for the same reason that you don't dig the foundation for a skyscraper with a tea spoon, nor try to put the coffee in your percolator with a steam shovel. Too coarse an abrasive selection would mean you never stop putting substantial scratches into the workpiece, and too fine an abrasive would take forever and a day to do a heavy cut.

So you start with however coarse an abrasive you need to remove the largest and deepest grinding or handling scratches in a practical amount of time, and you end with however fine an abrasive you need for the degree of final buffing you seek. Frequently, two compounds are not enough and you need three or four stages -- sometimes even more.

You also must select abrasives that are hard enough to cut stainless steel and are iron-free (such as alumina and green chromic oxide) because the use of iron will make the stainless steel prone to rusting. This is mostly just book knowledge, so readers are welcome to expand upon it or correct me.

Regards,

Thanks a lot ted. The main issue with us always has been these compounds. This is one of the most important steps of plating and finishing industry but in our country it is the most overlooked upon since one has to all the dirty work.

Thanks a ton.

A. There are a lot of other minerals out there that can abrade S.S.; however, normally aluminum oxide is the most common, the hardest and about the least expensive -- that is why it is used most. How are you going to use abrasive?

Q. We do not know a good performing abrasive rather than aluminium oxide. Silica fades away very quickly which we do not use. I tried using a lot but currently unable to get the desired results. If you could suggest a few items, I could well try that. Plus what should be ratio of binders? Could you suggest us on that.

A. If the media does not break down, it is not a good abrasive. That is why abrasive blast systems need to replace media periodically. If you want to try some hard crystal abrasive alternatives, you try garnet or zirconia.

A. All abrasives media comes in different sizes. The larger the media size the coarser the surface finish. Hardness of the metal also affects the finish. Most satin metal finishes can be achieved with anywhere from 60-120 grit size media.

Q. Thank you Mr. kenton. Also I understand that to satin metals the solid abrasive compound should be greaseless. May you please tell me which greaseless binder should I use?
Thank you

A. Okay. Considered your question and think it is basically proprietary info that I do not have access too; however, I can give you a generic answer. Polishing compounds can be in a liquid or solid form. Naturally the less liquid the thicker the polish. When it comes to solid bars, most use a form of grease to bind rouge but you can use glue products.

A. Hi Amit. Although grit size is one important parameter for polishing, there is a lot more to it than that, including what the abrasive is made of: aluminum oxide, emery, chromic oxide, tripoli, etc. It is possible that the green is made of chromic oxide (suitable for polishing stainless steel) and the red is emery not suitable for stainless because it induces rust. Even still, some manufacturers dye the abrasive bars to help you visually insure that it has all been removed before subsequent operations. If you tell us your situation, i.e., what you are trying to finish and what finish you need, it's possible that a reader will offer specific advice on which abrasives to use. Good luck.

Regards,

A. Amit,

I would not recommend using Ferric Oxide on stainless steel primarily to avoid contaminating a corrosion protected metal with ferric oxide. I haven't tested this, but simple mental evaluation for my own purposes is that it is something I would avoid. Chrome oxide is often times specifically used on stainless and therefore would be something I would go to for SS.

For copper, brass, bronze, zinc I would use brown Tripoli compound, although ferric oxide (red rouge) can be used and is on precious metals quite often and I'm sure would do a fine job on copper, brass, etc...

Both of what you have are very fine low cutting compounds and used normally for final finishing where polishing and low cutting is needed.

--Rama

A. In regards to the last question about mixing. There is nothing gained by using 2 different grit sizes. You will not get more abrasion faster or smoother than using one or the other. You will get a measurement of the rougher abrasive but you may not get an even visual appearance of it.

A. Hi cousin Sajad. As you can see, polishing is a whole technical discipline with some people devoting their entire careers to it. So please read this page and the free linked articles and try to fine tune your question with information such as what type of steel, what roughness it is when it gets to you, what roughness you want it to have at the conclusion of all your polishing and buffing steps, and what will be the next step (plating, painting, powder coating, galvanizing, oiling).

Is there a reason you can't just buy the already formulated polishing paste instead of having to buy all the individual commodity components? Thanks.

Regards,

A. Making of polishing buffing bar a hot sell is any manufacturer's dream come true. For those who have succeeded are millionaires already. Because here no amount of marketing helps. Only the product speaks. The formula is very much required from the experienced. It's priceless!

A. I have been polishing metals for some time, and I make my own polishing compound. I have read a lot of patents and try almost everything. I have gotten Mirror-like finish in SS by using 700-800 g chrome oxide (green powder), 150 g paraffin, 150 g tallow stearine (or stearic acid [on eBay or Amazon] ). You can try fused alumina, but you need a particle size below 10 microns, otherwise you won't have a perfect bright mirror like surface.
Hope it helps you!

A. Hi cousin Mohd. When you say you are you looking for someone to help, do you mean that you want to retain a consultant? If so, please post your inquiry as an RFQ so that we can share your contact info with the readers. Thanks.

If you are looking for free public help, did you follow the previous advice and read the two chapters in the online version of the Metal Finishing Guidebook as I suggested? Please download the book today because one of these days it probably won't be available anymore. If you have any specific questions, I think the readers will be happy to address them.

You might also try to obtain a hard copy of an earlier edition of that book because earlier editions have coverage by different authors so you will gain multiple perspectives. Good luck!

Regards,

A. Hi Nurul. I don't actually know how to formulate polishing pastes, but I do know that the purpose of the abrasive is to 'scratch' the surfaces. The problem might be that the mesh/grit size is too low for the fineness of the finish you are trying to offer.

Regards,

A. Hi, Nurul and other readers,
I'm not from the polishing or metal finishing industry. My comments are at best, general in this respect. Exact formulations, as had been mentioned here and elsewhere by Ted as well as others, are proprietary or Trade Secrets. As such, the exact form, particle sizes or the precise weight percentage of individual components within a product shall not be made known to the public on any SDS/MSDS of any manufacturer.
The basic abrasive most commonly used for stainless steel polishing is green chromic oxide. It's normally uncommon to find it as the sole abrasive in any commercial compounds for such applications. A fair amount of aluminum oxide, whatever the forms, are normally incorporated as well. In addition, depending on the products from different suppliers, fillers and other property modifiers such as calcium carbonate, silica (both amorphous and crystalline forms), kaolinite, etc are usually present.
The binders can be solid or semi-pasty at room temperatures. These usually are petroleum-based waxes and some fatty acids.
Hard alumina particles passing a 200 mesh sieve approximates 74 microns, which is not too different from what is found for the finer portion of hydraulic cement powders. These are suitable for removing deeper scratches, not for buffing to a mirror finish. You'll need softer materials which should crumble during polishing if that's the only size range available. The combination wouldn't be suitable for hard metals such as chrome-based alloys, which requires very fine, hard materials such as chromic oxide powders. These do not interact with the base metal to produce undesirable discolorations on such surfaces. As mentioned, polishing involves several stages from coarsest for scratch removal to the finest for the finish.

  Terrific explanation, Mark! Thanks!

Regards,

A. Hi Connie. Sorry it's dried up on you, but you'll never find exactly what solvents were in it. Kerosene might or might not loosen it up, but do that only outside because of extreme flammability, of course, and be mindful that a hot woodburning tip can therefore be trouble.

I would suggest, instead, getting some new green compound (it's quite cheap) and keeping it in a tightly sealed jar or wrapping it with saran wrap.

Regards,

 Hello from Connie McCollum. Thank you for your quick response to my question. I will go buy some more to prevent any problems. That was my first time visiting this site and I'm very impressed with the knowledge of the people who ask questions and the responses given. Again thank you.

A. Try archive .org website -- there you can find many download free old chemical formulas handbooks. (https://archive.org/details/in.ernet.dli.2015.198912?q=metal+polish)

Hope it helps and good luck!

A. Hi. If I were you I'd probably just label mine as "super concentrated", but you can look up the directions for whipped butter and see if simply whipping yours lets it keep the air in suspension to lighten it.

Luck & Regards,