Single or double stage to repaint a 86 ASC Mclaren

[merk23literturbo]

There is some confusion in this post that I will try to clarify without too much technical jargon. Single stage does not necessarily mean un-hardened Enamel.

First there was Enamel, then there was Urethane. Enamel paint may use a hardener to partially cross link the paint film. Urethane uses a hardener which has much more cross linking. That's why Urethane is more durable than "Hardened" Enamel.

The Sikkens OEM refinish products used were all Polyurethane, whether single stage or two stage(base/clear). If you want to refinish it as original then get some Sikkens single stage with Urethane hardener and find an excellent painter.

If you refinish it with two stage or single stage it will be VERY hard for most people to see the difference unless it is not done correctly. I have painted cars with single stage Metallic that were judged to be base/clear until I showed them the products and test panels for verification.

Let me explain. The single stage paint is made up of the pigment and the clear coat (Urethane resin) mixed together. The base/clear paint is made up of the pigment and clear coat (Urethane resin) separated. If you really know how to spray single stage to get the optimum results, the pigment will float to the bottom because it's heavier, and the clear will float to the top. The base/clear systems can be sprayed by anyone and look good.

If you spray the Urethane single stage incorrectly there will be a lot of pigment in the top layer. If you then sand the topcoat and polish it you will expose raw pigment (because you sanded off the protective clear and maybe even the binder) to UV rays. The unprotected pigment will start to degrade immediately and you will have to refinish the car.

It is easier to polish a base/clear job because the clear resin contains no pigment (large particle size) and does not leave as large a scratch which can show up as swirl marks. A correctly sprayed single stage can be polished without harming the finish or leaving swirl marks. Swirl marks are just small scratches in the paint, no majic there.

[PetesPonies]

almost....other than metallic settling in SS paints, there is nothing else to sink to the bottom. There is no seperation of pigments and other chemicals. There is no "clear" in SS paint, not as you would think of it. With a SS catalyzed paint system, you can sand all the way through it and find nothing different, unless it was a metallic paint.

[merk23literturbo]

Could you explain what you mean by almost?

I worked for Sikkens for a long time. I worked with the chemists who designed the paint products. Single Stage paint is designed so that the metallic floats to the bottom and the clear stays above it, when applied correctly. I don't make this stuff up. Where did you get your info?

BTW, Enamel is never Catalyzed. Technically speaking a Catalyst is a chemical that acts upon the surface of another chemical to speed up a reaction. It is not used up in the reaction. It can actually be recovered in some chemical processes.

Paint has a Hardener added to it. It is not a catalyst. It is used up in the reaction. It is part of the final product. Most Urethane paints will never harden without the hardener, some Enamels will.

And I said I was going to try and not use technical jargon.

All paint is composed of Pigment, Binder and Solvent. Many other things can be added, like clear acrylic urethane resin which will float to the top. You should be easily able to see that happen in a single stage metallic by spraying two test panels with the same paint except reduce one with extra fast reducer and reduce the other with straight retarder.

AIPC

[PetesPonies]

almost means I agree with most of what you said. I do not know the chemistry of Sikkens, so if you have facts I bow to them. However, I am speaking of non-metallic SS paints. When talking of metallics, the info is different. I did specify I was atlking of solid colors, not metallic. This originated about a red that is a non-metallic paint, right? If you want to discuss metallics we can, but I think you and I would agree. As far as solids go, there is no seperation of materials. Also, really we aren't talking about "enamel" at all here. We are talking about acrylic enamel. Acrylic enamel will harden on it own over time, a long time. So what speeds this up is a catalyst, that is added to the paint when mixed by the painter. We are not in agreement here? as far as urethanes go, yes they need the reactive material added to them, no choice.
where do I get my info? Well I have never worked for a company. I am a college graduate with a degreee in Industrial Education. I have been painting for 31 years. I like to learn and I am the type to work towards understanding what is going on as it is not enough to just use something. That might be fine for some, but doesn't satisfy myself. So I learn what I can. I also teach Auto, along with my restoration business, to high school students.

[merk23literturbo]

In single stage urethane there will be a layer at the top that is clear. You don't want pigments near the surface because they will degrade quicker. The clear layer contains UV protection. You will not be able to easily see the separation that I am talking about since the whole paint film may only be three to four Mils thick, unless you have very special equipment.

I salute you for your work. We need more people who are willing to teach the next generation. I always have an extremely hard time finding entry level people. I always look to the Vo-Tech's and sschools for help.