What is good metal polishing practice?
Is it true that the metal polishing industry deliberately perpetuates some of the myths and bad practices?
In some cases perhaps, whilst in other cases it may just be common errors of judgement.
In this section it is possible to discover why brass and copper crack and why some polishes will deteriorate by themselves in good environments.
All will be explained, so be ready to see some interesting facts.
Many of the statements you are about to encounter are controversial and fly in the face of what is considered by many as good metal polishing practice. Some of these myths are perpetuated by the industry deliberately. Some are just common errors of judgment. You will discover why brass and copper crack, and why some polishes will deteriorate by themselves in good environments. All will be explained. Be ready to see some interesting facts. Here is the inside story that the manufacturers don't want you to know.
What follows is the inside story that the manufacturers don't want you to know.
Myths, Half Truths and Lies
All Metal Polishes Are The Same
Absolutely not true.
Anti-oxidants, enhancers, grime removers, inhibitors, slip agents etc vary enormously from brand to brand
All Metal Polishes Will Protect
Polishing will normally protect any surface, to some degree. However, many metal polishes contain ammonia or what is termed anhydrous derivatives. These often appear in new and many old, trusted and established products, including household names. In fact they are the industry standard, and have recently been proven to cause premature aging of many alloys, especially brass and other copper alloys. Minute cracks and fissures appear after excessive use of ammoniates or anhydrous products.

Also, these chemicals will increase the tarnishing of the piece in the long run, and cause the item to lose its lustre fairly quickly. This means that even in a perfect, stable environment the items will need re-polishing. Manufacturers sell more products, which is good for business but bad news for your precious antique heirloom.
Polishing with the correct products will increase the life span of any piece if it is done correctly, whereas the use of ammonia and anhydrous products has been proven to do the opposite. A few manufacturers use mild acids instead of ammoniates or anhydrous. The result being that the acids etches into the metals instead.
One of the main things that make anhydrous chemicals so bad is that they will dissolve Zinc, a major component of brass, and nearly always present on aluminium castings. Zinc is also often used to stop steel from corroding..
Anhydrous chemicals can destroy these materials.
The manufacturers that use acids are no better than the others, they still damage your pieces.
All General Purpose Metal Polishes Are Good On Any Surface
Absolutely not true.
A polish that is good on stainless steel or chromium should be kept away from most soft metals especially gold, silver, platinum, pewter, copper and precious pieces.

If it is hard enough to cut stainless it will gouge soft metals easily and remove unnecessary material.
If it is good for finishing aluminium it probably won't touch chromium, bronze or stainless steel.
That is not to say that a polish for fine or precious metals won't work on harder metals. It will cut slower. But a polish suitable for cutting hard metals from rough finishes will tear gold and silver apart.
Rapid Acting Liquid Polishes Are Not As Good As Pastes
Generally speaking, yes they are, and more often than not, they are better!
The downside with pastes is that they tend to be harder to remove, especially if they get to dry out on your piece. They also tend to leave masses of dried polish in any small grooves or cracks leaving those ugly white lines. While the liquid metal polishes tend to dry out to just a powdery residue, they are much easier to remove than pastes.
All Polished Finishes Have The Same Endurance
Unfortunately not because some fade quickly especially when metal polishes that contain ammoniates, or anhydrous are used
The ones that use acids are not generally far behind them.
But also there are many others too. This can be caused by all manner of reasons. Lack of inhibitors, lack of protective waxes, or even the wrong waxes for the environment the finish has to endure. A bad ph. balance caused by the use of acids or alkali or even the protective wax, which is normally acidic, is another reason metal polish will fade.
All Polished Surfaces Should Be Waxed Or Lacquered For It To Really Last
Absolutely not true.
This depends on the environment.
Pieces subjected to ocean environments need protection with lacquers or clear coats.
Show vehicles want their bright work to be waxed where it counts; aluminium is normally waxed to improve the lustre. With stainless it depends on the quality of finish. Show chrome should never really need more than an ultra fine wax free maintenance polishing.
Areas subject to heat should be wax and lacquer free.
Antiques and museum pieces should be waxed with a PH neutral wax to protect them.
Lacquers and clear coats discolour with age. In fact most of them detract from the finish immediately. They also tend to crack and become porous. This allows oxidization to start again.
All Metal Polishes Can Be Used On Components Subjected To Heat
Absolutely not true.
Most metal polishes cannot be used on turbochargers, manifolds, cam casings, and similar components.
They go grey once they get hot, especially on exhaust pipes.
Only use a polish formulated for this type of application that contains a high melting point wax.
Surface Protection With Carnauba Will Last Longer
Sorry, Carnauba is acidic so it will attack what ever is underneath. It is also porous which means it will get oxidization going too. Just as a bonus it will probably increase pitting on road vehicles as well. This is because by putting a soft surface over your wheels, tanks or whatever - you are helping to guide the missiles in.
Carnauba is great for show vehicles that are subject to regular re-polishing, and useful for protecting from road salt in northern climates. otherwise, leave it off.
Antiques Should Never Be Polished
Absolutely not true.
An old piece does not necessarily have to be dull and dirty.
Most antique brass, copper and silver came from homes where servants were paid to polish these pieces. Should an item not be polished to a high lustre shine it would inevitably have led to the dismissal of the servant responsible.
How can one prevent or remove oxidization?
Antiques need to be restored and preserved. The aim is to maintain the original or factory delivered condition. Therefore, where applicable they need to be polished carefully, then protected by a museum quality wax and placed into a clean environment, where they will not be handled.
Over-polishing is another issue altogether.
A little grime should always be left in the cracks to show antiquity and allow for accurate dating. Always use the finest metal polish possible when dealing with antiques, and where cleaning is sufficient, that is all that needs to be done. Not too many people will be interested in an old piece of sterling silver, or brass if it is blackened with age and tarnished. Polish it with a quality metal polish and finish it with a good wax. It is as simple as that.
If a piece is going to be restored to its original condition, there is nothing wrong with that, because you are adding to its beauty.
Of course there are items that should never be polished.
Old tools in particular, normally do better in a used condition and so are not generally restored.
Black Pewter is not normally restored.
But with copper, if it is left to go green it will slowly erode away. Polish it, wax it, and it will virtually last forever.
Gold Metal Polish Can Be Used On Chrome
Sorry - it will not touch it.
It is true that jeweller’s rouge will not touch chrome, stainless or any other hard metal unless you are prepared to sit there for many an hour.
Finishing with it is another matter entirely.
Green Rouge And White Rouge Are Similar To Jeweller's Rouge
Absolutely not true.
Irrespective of what other people tell you, there is no such thing as green or white rouge.
Many manufacturers in the industry don't appreciate this, they call anything in a bar jeweller's rouge - but 'rouge' is French for 'red', and jeweller’s rouge is red because it contains ferric oxide. If it doesn't contain ferric oxide, it's not rouge.

Jeweller’s rouge was developed not just because of how fine it can be, but also because it stains the gold and gives it a sunny glow. Green and white rouge, as many people call them, are abrasive compounds, which are in most cases far too coarse to be used on gold or anything else of value. If you offered them to a jeweller as rouge, he would laugh at you.
For a start a good quality jeweller’s rouge is three times the price of any other compound. There are some abrasives that are as fine as jeweller's rouge and finer, but they don't behave like jeweller’s rouge, and jeweller’s rouge they are not!
Because of this generalisation we have seen very aggressive abrasive compounds being sold as products that were suitable for use on jewellery and precious metals. Not good!
All Abrasives Are Aluminium Oxide
Absolutely not true.
There are many people within the trade who believe this to be true.
Aluminium oxide is the most popular abrasive around today, next to silica, but abrasives can be, and are made from just about anything that will scratch and shine metals or plastics.
They are made from chromium oxide, aluminium silicate, zirconium silicate, carbides, diamonds, garnets, plastics and all sorts of interesting and sometimes oddball materials.
Regular Polishing Is The Best Way To Protect
Absolutely not true.
Occasional and rare polishing is the best way to protect.
A museum quality polish is not only very tame as an abrasive; it gives a long enduring finish. This keeps polishing at a minimum. When dusting or cleaning is sufficient to maintain a finish, then that is all that is necessary.
A museum polish should contain a PH neutral wax, if it contains any wax at all. After polishing maintaining the finish should be achievable by occasional cleaning with a museum quality wax.
The use of abrasives in a museum or on antiques needs to be rare and minimal.
Polishing In The Sun Is Fun!
Polishing in the sun is certainly fun, but it is also hard work. Everything sets so fast it's just plain old-fashioned hard work, plus the antioxidants evaporate, and the polishes work slower, but it is a fine way to get sunburnt!!!!!!!!
Lacquered Or Clear Coated Surfaces Are Easier To Maintain
For the short term the answer is most definitely yes.

But in the long term lacquered and clear coated surfaces are a devil of a job to re-polish and can get quite ugly.
In the marine environment lacquer or clear coat is a must on anything but stainless. However in an antique or museum environment clear coats and lacquers are problematic. Using a museum quality product keeps re-polishing down to a minimum. When re-polishing becomes necessary, even then it is a very easy process that involves minimal material removal.
Fine Polishes Do Not Cut
Yes and no
The ability for a compound or polish to cut depends on the shape of its crystals or particles.
What is governed by its size is how deep it can gouge.
Coarse grit may be fairly round and spiky, which will tumble rather than cut.
Many abrasives have wedge shaped edges protruding from triangular looking crystals. These slice easily. They can also dig into the surface.

However, a big round crystal that tumbles won't have a deep scratch. So the size of the crystal can be as important as the shape.
Coarse grit using one type of abrasive may be a finer cut than many finer grades even if it is the same type of abrasive. The manufacturer and the manner in which the crystals that form the abrasive are cultivated define its shape and cutting ability or scratch.
A Hard Compound Cuts Better Than A Soft One
Yes and no.
The shape of the abrasive crystal also determines how it will cut.
A hard compound or abrasive may also be brittle. Then it will cut once, lose its edge and won't cut at all, while a softer abrasive may hold its edge and keep on cutting.
A Polish That Is Good On Chromium Will Be Good On Stainless, And Vice Versa
This will depend on what is in the polish.
There are ways of highlighting the components of a metal, and chromium is an ingredient of stainless steel. It is the chromium that gives stainless steel its shine. There are polishes that are great on both. Many only excel on one or the other.
Brass, Bronze And Copper Polishes Are All The Same
Copper is relatively soft compared to bronze and brass, so it should be treated more gently.
Some Bronzes can be very hard, and the oxidization that settles on bronze most definitely is very hard.
Stainless Steel Does Not Rust, Oxidize Or Stain
A complete misconception is that stainless steel is stain proof. It is not, but merely stains less.
Austenitic stainless steel will not tarnish, stain or discolour easily, but austenitic stainless steel will, especially if it is overheated or allowed to come into contact with ordinary carbon steel.
All stainless steel takes on bleed marks and stains from other metals easily.
All Metals Can Be Polished
Yes, but not to make them shine.
Some manufacturers claim they have a magnesium and aluminium polish.
Well magnesium doesn't shine, not bright anyway. Because magnesium is a white metal, you can clean it and remove oxidization, but you can't polish it!
In magnesium alloys it depends on the amount of magnesium content that determines how well it shines.
Environmentally Safe And Low Toxicity Polishes Are Safe To Be Exposed To
Yes, no and maybe.
Environmentally safe polishes may use mild acids that occur naturally as active anti-oxidants. However, large quantities of fine metal particulates are not environmentally or physically good, especially soft and heavy metals. Large quantities in the body system through skin absorption and inhalation can have some very serious and long-term effects. Alzheimer’s disease, brittle bones, loss of teeth and skin disorders are just the beginning of a very long list of disorders associated with metals.
Always use barrier creams, face masks and whatever other protection is necessary to avoid contamination. One of the main problems with environmentally safe polishes is that they are poor performers. For the acids to be of any real use they have to be quite concentrated. Then they become not so environmentally good and often quite harsh skin irritants, so really the same rules should be applied to all metal polishes. Another draw back of acid based polish is that they normally etch into the metals and cause re-oxidisation.
Protect yourself.
Using More Polish Is Best
Many people over-use and flood metal surfaces with polishes believing that they are better protecting the surface. The assumption being the more polish the better the shine and protection, but this assumption is totally wrong. It is not true that the more polish you use gives a better shine; in fact the opposite is true. Using the least amount of polish and allowing the polish to do the work does in fact give better results. It is the grade, size, shape and hardness of the particles that determine how smooth the surface will become and not the volume of the polish used.

More polish creates a smudging problem since fingerprints (human body oils) "dissolve" the solvency of the metal polish. Additionally, too much polish may discolour the surface. Only a trace amount of polish creating a thin film should be applied, rubbing in overlapping circles using only light pressure. Remove the residue in straight lines using a soft clean cloth and buff to obtain a high lustre shine. Repeat until the required surface finish is obtained, and finish by applying one or more layers of a microcrystalline wax.

Using less polish gives better results
Using more polish does not increase the shine; it only wastes polish and your money
Every time another myth is uncovered it gets added to the above list
SKU Z 007
Z 007  Metal Polishing Myths