White Paint Longevity - How to prevent yellowing over time

[hendie]

I have read about white enamel paint yellowing over time - is this also true for acrylic white?

I think I heard or read somewhere that some people add a drop of blue to the white enamel and this prevents the yellowing occurring - anyone know if this is true or not?

Any tips and tricks for white paint to prevent the yellowing over time?

[Graeme H]

You won't get yellowing from acrylic paint at all, BUT, if you use clear overcoats anything can happen

The most common method for stopping yellowing is to add a few drops of blue, if it looks blue you put in way too much, the idea is less is good

This also works for enamels.

Now the theory is that Future or whatever your clear coat of choice, should not yellow being an acrylic, but I have read that this had happened to some, so the clear coats are something that need to be considered.

Now as someone who builds airliners, and I use a lot of white, I have always preferred to use automotive paints mostly, these are what are called Acrylic lacquers, and you don't see white cars going yellow, and if you are going for a gloss finish, they have spray cans of clear as well, that won't yellow, with these< I decant from the spray can and put it through my airbrush, if you wanted to do brush painting, something like GSI Creos (Gunze), or Tamiya bottles are good, keep thinning the paint and especially the brush.

[JohnT]

I didn't know that acrylic wouldn't "go off" so thanks for that info Grame. Very handy if doing a white Vulcan/Victor/Valiant.

I did know that enamels did yellow and remember being very disappointed as a kid when after a few years some all white models looked distinctly "off".

Good tip about the blue additive and using auto paints as you are right - you don't see a car go off white - usually !

Why does white (I used Humbrol enamel all those years ago - 1960's) go yellow over time anyway?

[Rick Brown]

Good tip Graeme H.

What do you use to clean the A/B with after using automotive paints and what to thin it with?

Cheers,

Rick.

[Flemming]

Hi

Use Tamiya spray TS-26 with a Gunze 'Topcoat' (spray) clear gloss/semigloss or matt and you won't have any yellowing. Just bright white. TS-26 will require a white primer though - Tamiya white primer is excellent.

Flemming

[PhoenixII]

Just get a rattle can of Halfords Appliance White....................Simples!

[Graeme H]

Good tip Graeme H.

What do you use to clean the A/B with after using automotive paints and what to thin it with?

Cheers,

Rick.

I usually buy a 4 litre (1 Gal) tin of automotive acrylic lacquer thinner, which works for automotive paints, Tamiya and Gunze acrylics, but not Xtracylics, and also Model master and Humbrol enamels.

Here it is often referred to as GP Thinners, for obvious reasons, also very good for Alclad paints.

As I mentioned there are certain acrylics that have a different chemical make up, which turn to a mess when mixed with GP Thinners, ones that I know of are Xtracrylics and Pactra, these need Isopropyl alcohol or similar.

Any new brand of paint that I might experiment with I will do a test with automotive thinners before putting it in the airbrush.

The chemical reaction that causes yellowing from enamels has long been recognized where house painters have never been able to use acrylics on say door frames and windows as they tend to stick together, and only enamels will allow them to open and shut properly, but the frames also go yellow over time, and it is only very recently that paint manufacturers have at last come up with a formula for a white acrylic type paint that doesn't yellow or stick together, and here is basically called Aquaenamel, to signify that it is water based, but with and enamel type finish.

[garryrussell]

I've not had any problems with while yellowing since there have been no smokers in the place.

I recently packed some stuf to move and the fiuse of a part finished Airfix Vanguard was as white as it was when it was painted in the late '90's. Humbrol matt white enamal...the top coat was not applied yet.