Diminishing Abrasives-

[TOGWT]

Diminishing Abrasives:
Diminishing abrasives require friction, not heat (that is just a by-product of friction) to activate and progressively reduce there size until they become a finite milled dust; they are buffered or cushioned in a lubricating water-based oil film emulsion, usually in a semi-liquid paste. Some very abrasive compound polishes don’t feel abrasive to the touch because the particles are formulated in a solvent or polymer oils in a water-based emulsion and are not released without friction. The abrasive start off as large particles, which remove the most paint, they are then reduced in size into finer and finer particles, removing progressively less of the paint surface, by the friction caused by the foam pads contact with the paint surface. By varying the size of the abrasive a differing cut is obtained, so the more the abrasives are reduced in size the finer the resultant finish until the particles are reduced to a very fine powder, which in turn produces a burnished surface shine.

The amount of size reduction (diminishing) can be adjusted by the type of abrasive material used allowing some polishes to used for the removal of surface scratches only, but if required can then followed up with a finishing type polish that contains smaller abrasives. Were as some polishes will remove surface scratches and by changing the abrasive ability of the foam pad will then go on to buff the surface to a shine ready for the application of a last step product (LSP)

Menzerna Professional polishes will not finish up dry, but will always have a hazy film to them. Polish to a ‘haze’ - when a polish "flashes" from a liquid paste to a light semi-dry haze; its colour changes from the polish colour to almost transparent; the polish has then broken down and is ready for removal. The point at which a polish is fully broken down comes with experience but a good yard stick is when the polish has become clear and can easily be wiped off.

It is important to know when a polish has broken down because if you take it too far you will re-introduce surface marring conversely if you don’t work diminishing abrasives sufficiently they will cause surface marring (this is due to the size of the abrasive and its cutting ability, were as once an abrasive has broken down it will burnish the surface as opposed to cutting it)

Menzerna have been producing this type of abrasive for use by OEM’s and has the most experience with this technology. They mill there own abrasives to ensure quality control within a size range of approx. 0.3 –0.4 µ (micron). The most common abrasive used is silica however; many formulators are also using aluminium oxide. Most good compounds and polishes contain diminishing abrasives and are a combination of both silica and aluminium oxide. Think of them as liquid grit finishing paper, they are formulated with a lubricant (polymer or solvent / oils in a water-based emulsion)

Most good compounds are a combination of both silica and aluminium oxide. The abrading ability of these compounds can be changed by their application method (i.e. machine speed and/or pressure used, using wet or dry and/or type of foam (different foam compositions have a differing abrading ability) Allow sufficient time for the polish to work, with a more aggressive polish a longer time period is required (approx 3 – 6 minutes)

TOGWT ™ Copyright © 2002-2007. Jon Miller, all rights reserved

[POPPAJ]

Another insightful post loaded with info. Thanks. Always wondered how this worked

[ss-truck]

I am learning a lot reading your posts . In the past I realize now that I have over polished , not stopping when the polish hazes over . I used to spritz with water and continue until I got a shine . I couldn't understand why I had so many problems getting the gloss , now I understand much more than ever . Thanks much for you knowledge and help .

[agentfx]

Thanks for that post!. Definitly added some insights to how those types of Polishes work