Yellowing - Paint/Plastic

Just wondering if there is a difference in the yellowing “rates”(?) of white paint versus white plastic? I’m building the Mike Follmer Watercraft Racer and wondering if I can slow down the yellowing process any by leaving the white plastic instead of painting it or vice-versa. Has anyone noticed any difference or am I just gonna have to take a lot of pictures as soon as I’m done. [:p][;)]

Ray

Ray,

I read somewhere that the ‘yellowing’ actually comes from exposure to something in sunlight. The suggestion was that if you kept it out of the sun, it should be OK. Come to think of it, I think it was in the question/answer section of FSM mag that I read that???

I’ve also heard that if you add a pinch of blue to the white paint, it will keep it white… Never actually tried it though…

Murray

I’ve had yellowing using ‘normal’ modelling paints, in particular the Revell and Humbrol white. So anything large and white, I now use a can of white automotive acrylic. I’ve got a number of airliners I built nearly 10 years ago that are still white as snow. The finish you apply after the white influences the look of course. Future seems to be the best product there, white the gloss varnish from Humbrol is probably the worst!

It is the exposure to ultraviolet radiation. This output not ony by sunlight but by regular light bulbs (although in much lower quantities)

To answer your first question yes there are different rates for the plastic and the paint. What they are I don’t knlow.

But to keep from yellowing do not expose to uv light and or store in a case with uv protecting sides and top.

Good info Domi. I’m glad I learned about the Humbrol white and clear because I’ve got a bit of a ‘flavour’ for the Humbrol paints lately (yes, my life is really that sad…). I’ll keep this in mind.

I’ve read articles in mags that you brits use a brand called Halfords?? Is that just an automotive paint like you refer to?

Murray

Brits! Brits? I’m from Belgium, home of the best beers, pankaces, fries, chocolate, biscuits and waffles! And graphic novels! And that’s about it! Seriously though (though I was serious about beers, pankaces, fries, chocolate, biscuits, waffles and graphic novels), yes, Halfords is a chain of fairly large automotive-parts shops and they have this rather amazing range of spray cans with great colours for car modelers (obviously), but also this very good range of primers and and a great gloss varnish too.

Humbrol remain my favourite paints, and I do use the white quite a lot, but anything that’s not really hidden and require a decent uniform coat that will not go yellow gets the Halford’s Plastic White Primer treatment.

Domi

I would probably stay away from the Humbrol White and normal Varnish, but the Humbrol ClearCote apparently does not yellow, I’ve had a model done in clearCote for over a year and no problems so far.
I have used the Halfords and Duplicolor automotive acrylic sprays for years and I’ve had no yellowing problems at all.

Yes…ultra violet light causes yellowing in paint and photographs. Being an ex custom painter of cars and such it was a problem for people who laid out tons of cash for a paint job…only to have it yellow in a few years. But in the 70’s paint mfg devised a clear coat that defuses the ultra-violet rays and disperses it evenly around the object…instead of directly on the surface ie. on the top. Many automotive paints are now available with ultra-violet arrester. Which includes enamels, and all other resin paints----------------hope this helps[8)]