Original Paint

Mike V. Florida

Mike V. Florida

Well-known member
We read here about original paint and color matching often. The sage advice has always been look for a place there the paint has been covered and you will find what the original color looked like.

I was just reading about Colonial Williamsburg and their paint studies when it comes to repainting the buildings in the village.

In the '20s they just sanded down the layers of paint until the got to the first color, matched it and then moved on the the next. Somewhat like we do with the cars. Turns out that with the help of additional research, scientists and chemists, after studying pigments, dryers and the such, it was determined that the colors found by sanding could be way off from the original color when first applied.

Linseed oil was a major part of the paint and it yellows with time. When mixed with Prussian Blue, overtime it turns to a green. The green colors used copper and copper tarnishes with the linseed oil very dark and so on. Some of the muted "colonial" colors were actually very vibrant when first applied.

It is the chemical changes, not just the UV, that changes the colors of the paints used in the 1700's.

I wonder if the same could be said for the automotive paint of the 20's and 30's?
 
Patina isn't always dirt and rust, stuff actually ages. I see it all the time in the historic home renovations I do, never thought of it much with vehicles, makes sence that it would...
 
When a pigment is mixed in a binder, whether it is a varnish, as used in the carriage trade up through the Model T era, or a linseed, walnut oil or casein (milk solids) binder like old house or barn paint, the binder is either the pigments first line of defense or it is its undoing.

If the medium is acidic, such as linseed oil, then the copper acetate pigment (verdigris green) will react with the linseed oil depending on how it is prepared, yellowing fairly quickly and in turn speeding up the yellowing of the oil itself.

Proxylin lacquers like used on a Model A (or last of the colored T's) have relatively low chemical reactivity- it "locks" the pigment particles in a somewhat inert film. As the surface wears, pigment particles will be exposed to the air and its elements and may alters the colors. Mediums that break down from UV create the "chalking" or whitish cast on some old paint.

Modern paints aren't immune to these problems either, as so many of the silver and metallic paints of the 70's and 80's show. In some cases the clear topcoat is the culprit. A pigmented paint is often stronger than a mere varnish (un-pigmented coating), even polyurethanes.
 
A good place to find the original color is under the original patent data plate or the original body number tag on the firewall.
 
my rust ball of an aa had trace amounts on the underside of the gas tank, looked to be gunmetal blue color. Once I got the door handles off it was very clearly rock moss green haha. Shiny orangy peel paint underneath preserved from sun and rain.
 
G Baese said:
When a pigment is mixed in a binder, whether it is a varnish, as used in the carriage trade up through the Model T era, or a linseed, walnut oil or casein (milk solids) binder like old house or barn paint, the binder is either the pigments first line of defense or it is its undoing.

If the medium is acidic, such as linseed oil, then the copper acetate pigment (verdigris green) will react with the linseed oil depending on how it is prepared, yellowing fairly quickly and in turn speeding up the yellowing of the oil itself.

Proxylin lacquers like used on a Model A (or last of the colored T's) have relatively low chemical reactivity- it "locks" the pigment particles in a somewhat inert film. As the surface wears, pigment particles will be exposed to the air and its elements and may alters the colors. Mediums that break down from UV create the "chalking" or whitish cast on some old paint.

Modern paints aren't immune to these problems either, as so many of the silver and metallic paints of the 70's and 80's show. In some cases the clear topcoat is the culprit. A pigmented paint is often stronger than a mere varnish (un-pigmented coating), even polyurethanes.
Click to expand...

Great info! All I had to go by was the article I read on house paint and was wondering about the Model A paint. Now I have your information as well.
 
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