acrylic on top of enamel what's the score

[NFWEM57]

On 09/07/2014 at 13:44, TheWeatheringMan said:

Hi All,

Don't do this under any circumstances - you will be courting potential disaster on your models.

Turps Substitute is not and has never been intended to be a paint thinner.

To use this to thin paint can and often will destroy the paint make up by causing the binder to cease to bind or the dryers to cease to cause drying.

It might just work in some washes as these are not paints in the conventional sense but to use Turps Substitute in paint is very risky and can very easily result in problems with the paint coat that cannot be overcome without destruction of the model.

There is also the fact that the nature of Turps Substitute will also be very likely to cause chemical damage to the underlying plastic due to solvent attack - turps substitute does not 'flash out' from the paint layer like white spirit as its less volatile and so remains active within the paint film far longer and thus is likely to attack the plastic.

Turps Substitute is basically rubbish left from another process that has little use other than cleaning brushes due to its solvent nature.

Due to what it can contain Turps Substitute is totally unsuitable as a paint thinner - please don't use it for that - the risks can totally ruin a model.

As a trained paint and solvent chemist this is something I've been asked about many times - as a modeller I've seen the results that can happen.

Regards

Hopefully this thread can answer a question.  What about using distilled turpentine, such as that sold by Winsor & Newton, as a thinner for enamel paint.  Not having an air brush set up at present, I have used it to brush apply multiple layers of wash coats of the same colour to minimise the brush effect before finishing off with a final layer of non-thinned paint.  It does leave aa glossy look at each stage hence the use of a final coat of original paint or a matt/silk varnish.  The advantage of the distilled turpentine is that it dries faster and there is, in my experience, little smell.  Your thoughts and experience most welcome.

 

Patrick

[97406]

I mix and match enamel (thinned with white spirit) and acrylic (thinned with the proper water-borne thinner) model paints, depending on what I have got in, and the livery. I tend to use enamel more for the yellow ends of diesel or electric locos. If I am spraying acrylic over a satin or gloss enamel finish then I’ll give the surface a very gentle rub down with 1000 grit of finer wet and dry paper, being  careful to avoid any raised detail. Sometime I do that if overspraying enamel over a shiny enamel base coat. Be careful overspraying enamel with cellulose rattle can paint.