I may of stirred up a hornet's nest by calling some products PRO.
Let's call them alternative coatings.
There is a common misconception that alternative coatings are special or hard to work with or cannot be purchased by just anyone. It's true that some need to be sprayed, some cured with UV, etc., but they're simply chemical mixtures optimized to protect the polycarbonate from UV. Also contain chemicals to self level on vertical surfaces.Nothing special.
Think of them as clear coats with extra UV adsorbers and formulated to apply to porous material like polycarbonate without dissolving it. They are expensive because the ingredients used (especially the UV adsorbers) are expensive; like $500 per gallon, but you'll likely use less than 1/10 of an ounce per headlight.
There are some great coatings available that are wipe-on, just like the spar/ms. Others are more geared to auto body shops with UV, bake, spray capabilities, etc.
When you start researching these coatings, many manufacturers will infer that you really need to buy and use their system or kit to get good results. This isn't true.
To get a professional looking restoration, you need to remove the old coating and replace it with a new one.
How you remove the old coating has little to do with the final coating you use, with the following exceptions:
Some coatings fill in better than others, so your final coat will require a specific level of prep. Most wipe on coatings (including spar/ms) fill well (1500 grit and up).
Spray on and thinner coatings do not. You'll have to finish to a smoother level first.
You don't want to sand any more than required because most of these coatings will adhere better to a roughened surface.
The other concern is chemical compatibility between your prep and the final coating, but this issue can usually be avoided by scrubbing the headlight with alcohol to remove any residue and moisture.
In general,most any of these coatings can be integrated with your current system. If you're happy with your current prep system of removing the old coating, you shouldn't have to change that.
If you're happy with the spar/ms, stick with it, but try to optimize it to meet weather conditions and lay down as thick a coating as you can.The thicker the coating, the longer it will last.
When researching alternative coatings, here are some tips:
Does it require spraying?
Do I need a compressor?
Do I need UV lights?
Exposure to sunlight or using UV lamps is the same thing.
Do I need to mask?
Masking adds time to your restoration.
Does it have a good reputation or recommendations from other headlight restorers?
What do other say?
Does it need 1 coat or 2?
Some water based coatings require 2 coats to get sufficient thickness, but cure in less than 5 minutes.
How long will it last?
This is a loaded question, but most of these coatings should last at least 2 years average.
Is it hazardous? (shipping restrictions)
Are MSDS availabe?
Can it be shipped cheaply? (water based vs. solvent based).
Most of the best coatings cannot be shipped by air or internationally.
What does it cost per headlight?
Keep in mind that many vendors fib a bit about how many headlights you can do per can, oz., etc. Spray cans usually yield about 1/3 of the material on the headlight. 1/3 is propellant and spraying is about 50% efficient. But even if they over rate, your actual coat per headlight will probably be a small fraction of your restoration cost, usually less than a dollar per headlight.
One advantage of some of these alternative coatings is that less prep time is required, lowering your labor costa and increasing your profit margin.
As an aside,some of you may be having issues applying wax/polish to previously restored headlights.
They seem to cloud up quickly.It could be a chemical reaction between the coating and your wax. Spar is fairly soft when young and easily dissolved by many solvents.
These coatings are out there and easy to find with a little homework, but remember this is AG's website so we shouldn't get too specific. They're doing us a favor by allowing us to share information and we should respect that. Their house, their rules.
ray6
Where can you buy 100% alcohol?