Polishing Metals (Including Jewellery), Glass, Plastics

How to polish metals; how to remove scratches from glass (including windscreens and shop counters).

Scratch remover for plastics (including soft plastics such as acrylic and plastic watch crystals)






This is how scratches were removed in a windscreen factory. Use a polishing motor on its slowest speed.  Use a large cotton mop.  While the mop is spinning apply by holding the block of rouge against it. The rouge is very soft, it will come off easily, there is no need to mix it with anything. If the scratch is deep enough to feel with your fingernail it is too deep to remove by polishing.  I assume that if this method works on glass car windscreens it will also work on ordinary windows, and glass shop counters and display cases (even 'watch glasses' providing they are made of glass).

How easy is this to do? Well...it's possible, it's worth a try rather than buying a new shop window or expensive showcase, but it's not necessarily 'easy'. A company specialising in taking scratches out of glass was going to market a D.I.Y. system of mops and polishes but changed their mind. They said, if you are too gentle it simply doesn't work and if you are too enthusiastic the glass gets hot and shatters, which is why they charge a lot of money to come to your shop and polish a scratch out of the glass. So I can't promise you'll do a perfect job, but it's certainly worth a try!

Do you really need a polishing motor, can't you do it by hand? I tried to remove a myriad of fine scratches from a car mirror without a polishing motor.  After 6 or 7mns of very hard rubbing with a soft cloth (having heavily smeared it with rouge) I came to the conclusion that it wasn't making the slightest difference and I gave up.  It may have worked if I had kept rubbing for several minutes more -but I didn't have the patience - and the mirror remained scratched.

I took my own watch to a jeweller to get a new 'glass' (it was made of plastic and it was badly scratched) and he took it upstairs to his workshop. Ten minutes later he brought it back and it was almost perfect. He realised that the scratches were too bad for the plastics scratch-remover (see below) and so used standard jewellers rouge, but because the scratches were so deep, he had to use a quite 'hard' polishing mop (rather than the usual soft mop) and he had to use rouge rather than the plastics 'scratch remover'. As a skilled polisher, he knew just how hard-and-long to polish in order to remove the deep scratches without totally destroying the 'glass'. So it is possible to polish bad scratches out of plastic but you have to use a polishing motor (you won't manage it by hand) and you do need considerable skill.

For the novice, polish plastic with scratch remover. This works well on soft plastics such as acrylics. Typical items made of soft plastics are: some 'watch crystals' (though they should be made of a hard plastic), most display stands, simple handheld magnifying lenses, some very cheap reading spectacles and sunglasses. Scratch remover will not work on hard plastics such as polycarbonate (or any lens described as 'scratch-resistant').

There are many hundreds of different types of plastic, if you don't know if your plastic is 'soft' or 'hard (i.e. whether to use scratch-remover or rouge) try it and see. If the plastic is too hard, the scratch remover will have no effect. If the plastic is very soft, it will probably work. But do take care. My recommendation, for anything expensive (and all lenses) is: if you have a choice between throwing the item away or trying to remove the scratches, then try the scratch remover, you've nothing to lose; if the item is expensive, you may prefer to suffer the scratches than risk destroying it with over-polishing.

To use, mix scratch remover with water to form a paste the consistency of double cream, apply with a small felt mop on a miniature polishing motor, go carefully - you are only polishing a scratch not drilling for oil.  This is the powder used in the aircraft industry for polishing the acrylic canopies of aircraft. As with the rouge, it will only work on fine scratches.

For cleaning jewellery (gold and silver) IN A WORKSHOP:
- use a soft cotton mop on a polishing motor (e.g. 6 inch mop), as it's spinning press the stick of rouge against it until the mop turns red, then press the jewellery against the mop. Any crevices, especially the backs of stones, will become dark red from the rouge. This is normal. Wash out in an ultra sonic cleaner and dry by throwing it into a big bowl of hot sawdust (e.g. an enamel bowl full of sawdust on a gas or electric heating ring).

For cleaning jewellery (gold and silver) IN THE HOME:
- smear the rouge (rouge block or rouge powder onto a cotton cloth, then polish using a gold polishing cloth. For the inside of a ring use several strands of linen thread, tie one end to an immovable object, smear with rouge, slide the strands inside the ring, pull taught, rub the ring up and down. Any crevices, especially the backs of stones, will become dark red from the rouge. This is normal. Wash the item in hot soapy water, cleaning the backs of the stones with a soft toothbrush then leave to dry on tissue, give it final shine with a gold polishing cloth.

For cleaning jewellery (any soft metal...not steel or chrome), ALTERNATIVE METHOD:
- use polishing sticks, starting with a coarse grade to remove bad scratches (you should do this anyway, before you start polishing with a polishing compound), then work your way through the grades to the finest, then vigorously rub with a gold polishing cloth. This is good for flat items (since the polishing sticks won't get into fine spaces); this good as a 'quick-fix' for removing the stains caused by testing acids (you are not aiming to polish the item 'as new', merely to remove a stain); polishing sticks will not give the brilliant jewellers-rouge shine.

To remove tarnish (blackening) from silver there is a special chemical, and we have a silver cleaning cloth that is impregnated with this chemical.

In a professional workshop for polishing ('polishing shop') many different grades of polishing compound are used. The polishers (people) who use them have probably had a three year apprenticeship to learn polishing, so it really is difficult when we get calls saying, "How do I use polishes?" 

For soft plastics, silver, and the final high-shine polish on gold - see above. For polishing everything (e.g. silver trays, platinum rings, small earrings, large pendants, fancy chains, pitted bronze, brass candlesticks, filigree dishes, silver salvers...) you will need a dozen different grades of polishing compound, several different types of mop, and an awful lot of experience.