Polish Like a Pro

Written By: Jay Broom, Marketing Specialist, Lake Country Manufacturing

The most important thing to polish?

Polishing glass ranks as one of the most overlooked detailing skills and services. Aside from being aesthetically pleasing to have pure transparent glass, it’s incredibly important — a matter of life and death — to be able to see the road ahead properly. With the low sun, rains, and grime of winter upon us — sorry Southern hemisphere — I think now is a great time to talk about how and why machine polishing glass is so important.

Here are two glass polishing methods that may help detailers to demonstrate skills, knowledge, and professionalism in their services.

Machine polishing glass to clean it

Cleaning glass with a liquid cleaner typically removes surface dirt — but if you then wipe over the ‘clean’ glass with a damp cloth, do you notice you can still see streaky impressions left behind? These leftover stains are fallout, acid rain and chemical residues on the surface. Not only are these residues highly resistant to most glass cleaner sprays, a stained surface tends to get dirtier and more stained more quickly. It’s much easier to maintain a clean surface than have to keep restoring it. Fortunately, one of the easiest ways to fully remove glass staining is by simple machine polishing.  

In our workshop we keep old microfiber pads for this purpose specifically, helping to extend their life. Simply take your orbital polisher and pad, apply a medium cutting compound, and polish the glass in sections. Perhaps look at a windshield as quarters. To save time, put individual squirts of compound on the glass in those sections before you begin.

Don’t be afraid to apply some pressure — you will clean the glass faster, and it won’t cause any damage. It also won’t do anything at all to remove any surface scratches from the glass. All you’re doing is cleaning it ultra-efficiently. Remove your residue, clean with I.P.A., and you’ll see those streaky stains are gone in no time!

Machine polishing glass to restore it

A beautifully detailed paint job will be thoroughly let down by a scratched windshield. While the paint pops, under many light conditions the arcing scratches caused by gritty old wiper blades — don’t forget to clean or replace these afterward— are an unsightly distraction. Not to mention a potential safety issue in the worst cases, as they can increase glare for the driver.

Machine polishing glass with microfiber will not remove these scratches.  However, with rayon glass polishing pads and a special compound, you can!

This is a slightly trickier skill, but anyone with a moderate amount of experience should be able to master it quickly. For faint scratches, a random orbital polisher and a 5” rayon pad will do the trick. Deeper scratches may require a rotary and a 3” rayon pad for extra, more targeted cut. Glass polishing pads are a different material to those used on paintwork. When combined with a cerium oxide solution, they are aggressive enough to remove scratches in the glass, returning a pure optical clarity. Cerium oxide can be bought as a pre-mixed solution, or you can buy it in powder form and mix it with water yourself. A thin, watery mixture is usually strong enough — start from there, increasing the cerium oxide content if necessary.

What to watch out for

There are three main side-effects to watch out for when machine polishing scratches from glass — heat, scalloping, and chips. During glass polishing with the rayon pads, heat needs to be controlled, and the solution should not be allowed to dry out as it gets warm. The best way to achieve this is by misting a small amount of plain water onto the work area at regular intervals. If you’re lucky enough to have a glamorous assistant, this is the time to have them nearby!

When tackling shallow scratches across a large area or a whole windshield with a 5” rayon pad and random orbital, scalloping is highly unlikely to be a problem. However, if you were to remove a particularly deep scratch in an isolated area it’s possible to create a slight fishbowl/lens effect in the glass, aka. ‘scalloping’. You could mitigate this by blending/fading the scratch removal area outwards, making any indentation less sharply pronounced.  

One final pro-tip is that the cerium oxide solution has an unfortunate habit of setting hard in any chips, becoming very difficult to remove in many cases. This could be more distracting than the situation initially was, so under certain circumstances — deep scratches, lots of chips, or a combination of both — it may be best to look at the cost of replacing the windshield, weighing the pros and cons.

After machine polishing glass

Once you’ve finished polishing, completely wipe away the compound residue. Then, use I.P.A. and a different microfiber cloth to guarantee a pure surface. If planning to apply a glass coating, I would also recommend cleaning the glass with a strong solvent panel wipe before the I.P.A. This helps ensure that there are zero oils left that could inhibit the coating’s bonding abilities.

For more on this topic, and quite an extreme example, check out this YouTube video featuring Kelly Harris and some unusual scratches on a Porsche window.

Until next time – drive safe!

*This educational article was provided by Lake Country Manufacturing, Inc., an IDA Diamond Sponsor. It does not constitute an endorsement, guarantee, warranty, or recommendation by the IDA. The IDA makes no representation or warranties about any information contained herein.