only set back

randypandy831

I heard that yellow and white will not go down nice without a good prime.

I would dispute that one - if the surface is properly prepared before painting there is not really any reason why lighter colours would go down any better or worse with or without primer. One thing to take into consideration with lighter colours is weather the primer coat will darken or lighten the surface you are painting - if you start out with a white styrene kit & blast it in a  strong grey primer, you will need more coats of the lighter top coat to get an even coverage, although the opposite can be said for putting a light primer on a dark kit.

Primer is mostly used to fill fine surface imperfections, show up any flaws prior to top coat & to help with adhesion, they are also handy for giving an even base if you have a model that you have put plenty of contrasting filler on. I spent a good part of my life in the automotive trade, where primer is generally used (more to do with the base materials & performance requirements though) & put the same idea to practice with modelling - but time has proved that idea wrong, as primer in modelling is far more optional & not exactly a requirement.

If I had a light kit (lighter than the primer) I would probably give the primer a miss, but if I had a dark kit or one with considerable contrast I would prime with a light primer.

Light silver is sometimes used as a base for white as it can be easier to cover than grey & can give a nice end result. As for regular primers, Alclad primer is good through an airbrush.

Hi

I'm by no means an expert, (!) & regard my self as an 'improver', & first bought an airbrush to try & get a decent yellow finish on a Hotspur glider. 

some 30(ahem) years later, I'm still trying.....

A few thoughts.... I always prime, as I prefer acrylics, to get your target as smooth as possible.

Mr surfacer 500, 1000, or 1200 can be sprayed, the lower the number, the more body & thicker the paint, for sanding. eg., I Hand-brush Mr Surfacer 500 to stipple texture on armo(u)r!
The higher the number, the finer the finish.
Thin with Lacquer?/Cellulose (test first, American isn't always the same as English )

I use Vallejo Polyeurethane primer, available in grey, black & white, gives a smooth finish,but can give a 'crumbled' effect on edges if you sand through, easily fixed with anotther touch of Vallejo primer.

Once you are happy with the Vallejo primer coat, pref. white in this case, then spray yellow over it, thin coats, several times is better than trying to get a solid coat, as acrylics are not as opaque as some.

Perhaps you have a target you could practice on?

After terrible results using 'hobby specific' yellow spray cans I reevaluated the process.

Realize all paints are not created equal and for whatever reason certain colors are difficult to get good results, yellow is one of them.

It is necessary to have a base coat of flat white, the flat has more 'grip' for the top coat to adhere to. Next I though 'out of the box' and tried 'Krylon 'Sunbeam' spray can specific for plastic...

The results were excellent!

I painted a spinner cap for a 1/32 scale P-51, it came out so vibrant it had to be toned down with weathering & washes!

As all new techniques experiment on something other than your latest masterpiece.

thanks for the awesome info. 

reason why i asked it because i got done building revells 1/48 BF 109. i used surfacer 1000 and sanded it down and the yellow came out pretty.

i starting working a 1/48 spitfire and the tips of the properly are yellow. i repeated the same process as i did with my BF 109 and it came out like crap. i'll give it another try.

again thanks for the info.