Color Sanding & Polishing for Perfection – the way to a flawless finish
I am sure you have noticed an outstanding paint job, one that looks a mile deep and incredibly shiny. On closer inspection, you see no dirt or orange peel, it looks perfect – everywhere - like a mirror! It was most likely color sanded and polished. This is often the difference between a “nice” paintjob and a “wow” - what a paintjob!

The great thing about clear coats is that with patience and care you can sand out flaws and return the gloss with compounding and not damaging the colour. Unless you have access to near perfect conditions and are very adept and experienced at spraying, the chances are you are going to have a few imperfections in your finish. Depending on how severe, you can sand and reclear or color sand and polish. If you have a lot of runs in hard to get at places, you will most likely sand through the clear and damage the color getting them out, in this case you have no choice but to repaint (at least that area). If however you just have some dust, some dry spots or minor orange peel and have a good film build of clear, color sanding the panels flat and polishing will give you a near flawless finish, and at the risk of giving away some hard earned secrets, here’s how.

The process involves sanding the clear completely flat and using a polisher (either air or electric) with a buffing pad and compounds to return the gloss. It is important to realize that the buffing pad cannot be used on high edges or it will burn through the paint instantly, so when sanding leave about a finger thickness from any high edge when sanding so you don’t have to hit these edges.

Note: polishers are high torque machines that run around 1500 to 2500 rpm, do not use a tool that is not designed for this or you could ruin your finish or not return gloss. Hobby machines as they sell at CTC and Sears will not accept the 5/8” standard pad mounting of professional buffing pads. Black and Decker make an inexpensive electric polisher that is readily available.

Most urethane clears have a window where they will buff up quickly and easily, this is when the clear is not fully hardened but has set up, usually a day or two after painting. If you leave it too long you may find it very difficult to buff out the scratches left from sanding.

The real secret to polishing is in the sanding. There are specific sand papers designed for this, in both dry paper designed for an orbital polisher and water paper for hand use. Like most things in life, you get what you pay for and this is never truer than with fine grit papers for polishing.

Dry sanding with an orbital sander is a relatively recent option; on large flat panels it work’s wonders as you don’t get any deep scratches that sometimes occur when wet sanding by hand. The draw back is you are limited in getting in to tight areas and you need a good fine-action sander and you will use a lot of paper. Use a hard pad on flat areas and a soft foam on curves, start with 1000 - 1200 and finish with 1500 In water sanding, you need several grits and a small hard block (for flat panels), a hard foam backing pad (for curved areas) and a small squeegee to clean as you go. Presoak your paper in warm water with a little dish soap added, and you can use a sponge or a trickle hose to supply clean water to the area you are sanding.

When you begin sanding, do not put the paper back in your bucket – use the sponge to supply your water and keep it clean. I usually start with 1000 grit (on a block) to completely flat the area and knock down the dust, follow by a re-sand in 1500 to 2000 grit with a hard foam backing pad. Do a small section at a time using your squeegee to check you progress as you go. Sand in well lit and fairly quiet conditions, if you pick up some dirt you will hear it squeak – stop sanding and clean the area and the paper or you will end up with deep scratches.

When you start polishing you may find a few deep scratches that are very hard to remove, re-sand the area at right angles to the scratch with the 1500 and 2000 grit, dry as you go – you should see if the scratch is removed and you can resume polishing. If you are dealing with a clear run or sag, start with a block and P1000/P1200 until it is leveled and resand in finer polishing paper grits, if you start with the finer grits you will find it tends to follow the bump instead of eliminating it which becomes visible when polished.

There are numerous compounds and polishing pads available, most of the systems work well if you follow the manufactures recommendations. The professional brands are Farecla` (what I prefer), 3M, Mothers, McGuiars, Carbrite, Car Groom and Pesto which are available at automotive paint suppliers. Generally you start with a fairly aggressive compound to remove the sanding scratches and work up to a finer polish to return full gloss. It is important that you clean off the residue between steps and you polish long enough in each stage to get it as good as you can with that product stage. This can be very tedious so start with small sections and complete to your satisfaction.

Lighting greatly affects results, you may think a panel is polished and view it in a different light and see dull spots or scratches that require more compounding. Foam pads tend to leave few swirl marks when compared to wool pads although the wool pads cut faster. If you are starting with a wool pad, be particularly carefull when buffing near high edges as they develop more heat and can burn through the finish in seconds. Buffers turn in a clockwise direction – always angle to spin off an edge as opposed to spinning in where it can catch it. If you have finished buffing your panel, products such as Mother’s Show Time or MeGuiar’s Final Inspection are great for removing the last bit of residue by hand with a soft cloth. A properly buffed finish should not require glaze or wax to shine swirl free although these may be needed to maintain and protect the finish as time weathers it a bit. Once a year, a quick compounding with a fine finish grade polish (no sanding) will keep the clear looking as fresh and shiny as the day it was sprayed.

John