To Primer or not (Acrylics)

[Andy123]

Just wondered what the protocol is for primer please.  Obviously for main outside of models I airbrush primer before anything else but should I also use it for things such as cockpit parts and other visible interiors?

Intention is to use my Vallejo primer through an airbrush but will brush is its only small parts.

Thanks

[Steve Noble]

It depends on what the part is. I build cars and bikes mainly, so I certainly primer the body and exterior parts. Some of the interior parts, such as seats and stuff I probably don't primer..

[Giorgio N]

If you're going to use Vallejo and other similar paints, prime everything ! These paints will not stick well to plastic unless there's a suitable primer on the surfaces. You may get away without primer on some small bits but on larger ones the paint may wear off just by handling the parts.

Your plan is sound and is pretty much the same I do: airbrush over all main parts and brush for the smaller parts or those that are hard to reach with the airbrush (for example inside the exhaust cans). Now cockpit parts depend: personally I assemble the main cockpit parts together (like tub and main bulkheads) and prime with an airbrush. I also prime panels with the airbrush but before gluing them in place, if possible leaving them on the sprues. If this is not possible, I cut the parts, clean them and then stick them onto tape  to keep them from being blown away. This because it's generally impossible to paint all details on such parts after they are in place. For very small parts like control sticks I often just use a brush. Vallejo's primer can be used with a brush easily and will level nicely.

Other parts, small and not so small, require the same kind of thought: can I prime and then paint the part after it's been assembled with others ? Or will this interfere with the construction or painting process ? If it's possible, it's easier to paint the parts after assembly, if not better prime separately. There's no set rule, will depend on the kit and your approach to the build.

[roginoz]

My choice is to prime all the sprues immediately after opening the box [prior to building, not for occasional fondling.......] and clean up the mating edges as I go, Tamiya rattle can being my primer of choice, although I sometimes airbrush Stynylres [sp] if it's too hot/cold/wet to spray outside.

 

Mother Bear has a policy about use of spray cans in the house.........

 

Rog

[Timn]

I was told Tamiya doesnt need primer.

[fewr9fkr9595]

On 30/11/2020 at 10:09, roginoz said:

My choice is to prime all the sprues immediately after opening the box [prior to building, not for occasional fondling.......] and clean up the mating edges as I go, Tamiya rattle can being my primer of choice, although I sometimes airbrush Stynylres [sp] if it's too hot/cold/wet to spray outside.

 

Mother Bear has a policy about use of spray cans in the house.........

 

Rog

Waste of time as you’d need to prime again to check seams anyways. 
Plus you’re making more work for yourself having to clean all mating surfaces. 

[fewr9fkr9595]

4 hours ago, Timn said:

I was told Tamiya doesnt need primer.

Someone wants you to fail then. Punch them.
 
In some rare cases or small parts perhaps not. Any paint or kit will generally perform & or look better with the assistance of a primer. 
 

PS, Assuming we are talking regular tamiya acrylics here. 
 

The lacquers or enamels will give more options but still work best over a smooth, prepared and seam/blemish free primed surface. 

 

[RobL]

I don't even bother priming.  It's just another layer that will potentially clog details.  I just put down a black or grey undercoat using normal paint (usually Tamiya acrylic funnily enough) and go from there.

 

Never had a problem since I stopped priming, and the paint on models looks no worse, especially as I was using Vallejo polyurethane primers.  Also makes it easier to strip back...

Edited December 1, 2020 by RobL

[Stef N.]

7 minutes ago, RobL said:

I don't even bother priming.  It's just another layer that will potentially clog details.  I just put down a black or grey undercoat using normal paint (usually Tamiya acrylic funnily enough) and go from there.

 

Never had a problem since I stopped priming, and the paint on models looks no worse, especially as I was using Vallejo polyurethane primers.  Also makes it easier to strip back...

I'm the same for AFV builds. Using Tamiya I use a much darkened version of the main colour as a base/primer coat and haven't found any problems so far. By the time I get to a gloss coat I have put down 3/4 layers of different paint (more if a camo scheme is used.)

Saying that, I will use a primer on any etched parts as they are easier for the paint to come off,

[MrProd]

Priming is a really good way to see how well seams, sanding, filling etc will look so a good idea. Mr Surfacer 1500 will not clog or hide surface detail at all. If it's thin enough to airbrush and you aren't hosing it until pools I can't see how you'll fill panel lines etc.

Regarding what Giorgio N said about some paints needing primer more than others I can't really speak to as I only use Tamiya and Mr Color acrylics, but I think some plastics need primer more than others. I don't normally prime all the small parts but if I do another Eduard kit I'll prime everything. Their plastic didn't seem to like acrylics without primer.