Flat Paint

What makes flat paint "flat"?

 

It has to do with the pigment content and type. One of the paint pro's may be able to expand on that.

 

I'm a pro painter but I have no idea - might take a chemist to explain and then it would be over my head

Paints are formulated for different uses so it's best to buy the type of paint that best fits the job.

 

An explanation I got and it referred to automotive paint was that the chemical makeup of gloss paint allows certain compounds to rise to the surface.

I use to paint a fair bit of commercial equipment with automotive enamels.
I would add a few drops of a flattening compound which was just a clear liquid to the paint to kill the gloss.
This is also what the paint supplier would add to something like a vehicle interior paint to make it shine less.

A high gloss compressor or machine stand looks pretty cool at first but the scratches that come later make it look pretty shabby compared to a dull finish.

 

I know there are additives available to lessen the sheen on solvent based enamels but I don't think there is an additive to dull the sheen in latex enamels - at least I've never used/heard of one.

 

It's a function of the ratio of pigment (TIO2 and less expenssive fillers) to vehicle (latex or oil). Flats have a high ratio so that when the paint dries, the pigments are left exposed and light is scattered. With higher sheens, these pigments become buried in the vehicle - when they are completly buried, you get your highest gloss.

 

That doesn't seem to make a whole lot of sense to me. If that were true, higher gloss paints would have a poorer hide than flats, since they would have less pigment. I do not think this is the case.

SirWired

 

With non-quality brands, I have found that this is the case. Higher glosses do not hide as well as flat finishes (compared side-by-side in the same color). When it comes to quality paint... I'm not sure if this holds true.

 

I have always had better luck with gloss paints standing up over time. I have used the "flateners" referred to for enamels but I can't seem to find them any more.

I used a Sherwin Williams two part epoxy on a railing last summer. It turned out to have a semi-flat finish on it and seems to be doing okay. On another part of the building with used a catalyzed urethane. It was glossy. I thought that I would like the flatter finish but actually I believe the gloss looks better.

In another building we refinished some lights. Part of them we had powder coated. Another part we primed with epoxy and painted with catalyzed urethane.

It will be interesting to see which one turns out best.

 

SWP has a gloss modifier than can be used with oil base enamels but I don't know if it is available to the general public.

 

marksr,

Thanks for the tip. I have a SWP account and will ask them about it. I used a SWP black two part epoxy that came out quite flat. I was surprised because I expected a gloss.

It sprayed just fine but I will see how it comes out in the long run.

I posted a couple of pictures. One was a crackle finish epoxy that is used to be a tougher finish without showing scratches. The other one was a bed liner. I know that these are tough but they seem to show dust pretty badly.

The moderator called the pictures "showboating" my work and pulled the pictures.

Have you had any experience with these crackle finishes and how they stand up?



Thanks again,

Jim

 

"Have you had any experience with these crackle finishes and how they stand up?"

No, I've not used them.