Primer. How much do you put on?

[starmanmm]

I have noticed that when I do prime a kit, that most of it comes off when I wet sand it (400 grit). May be I am putting it on too light of a coat?

So, I know you can't put on too much for you may lose some details, so how heavy of a coat should you put on it.

[Kylwell]

A proper primer coat doesn't need to be sanded if it's the final one. I've started using primer to show the flaws it a build or to fill micro divots (thank you Mr. Surfacer 500). But if I'm using primer I always give it one last shot to cover everything for uniformities sake. What kind of primer are you using? Some of the heavier primers you have to watch obscuring detail but the fine primers (Tamiya, Mr Surfacer 1200) I've never seen too much detail loss.

Mind you, I'm no where near a primer god, tend to avoid it if at all possible but this is what I've learned.

[starmanmm]

For primer I use either automotive or Kyrlon. I use the automotive if it is a resin piece.

My undestanding is that you prime for several reasons. First to find problems and second to give it a base coat for the main coat of paint to grab onto.

Once you fix any problems, then you prime that area again, let it dry, and then wet sand to smooth it out for you coat of paint.

[Warped Speedster]

My undestanding is that you prime for several reasons. First to find problems and second to give it a base coat for the main coat of paint to grab onto.

Once you fix any problems, then you prime that area again, let it dry, and then wet sand to smooth it out for you coat of paint.

That's the same thing I use it for.

As far as how much primer to put on probably depends on how much work or how many corrections need to be made to the surface. I don't know if you're applying Krylon out of a rattle can or with an airbrush, but airbrushing is always better. You can apply it heavy to the areas that need it the most and light on the detailed parts.

400 grit may be too rough for the thin coats. You might wanna try 600 or even 800 grit on areas where the paint is thin. But I often do use 400 where I sprayed it on thick to make those big surface repairs.

You can usually tell by looking at your model where the paint needs to be thicker. If you miss it then just go back and spray on some more. Since you're sanding it anyway it doesn't matter how many times you go back to primer an area. You can even brush primer into a trouble spot like a hairline crack or even a gap. Just let it dry and thicken like a paste before brushing it in. Air brush or paint brush, you just paint and sand until you're happy with it.

Same goes with your final base coat. I usually always give my final coat a light sanding with 800 grit wet and dry and then lightly buff it with a paper towel. But sometimes you find problems with your final coat that you didn't see in the primer coat. Not a big deal really, you can always add thickened base paint into a small gap with a paint brush. Just lightly and carefully sand it out the same way as you would with primer. For the past few projects I've done I've been giving them enough base coat to make any final corrections that may need tending to. What ever it takes.

Hope this helps.

[starmanmm]

It does.

I think the problem maybe that I should be either using something finer to sand and or spray (I am using a can) a little heavier coat on the kit.

Like I said, I have been sanding thru to the plastic and I know that I was not pressing that hard. So, on the next kit, I will try a slightly heavier coat and going with 600/800 grit.

[TER-OR]

Primer....painting....finishing forum.
All hands in the car, the thread is about to move.

[Mark Yungblut]

I will usually primer my model once the parts ar together and the initial filling is done. After a few days of drying time I rub the entire thing down with an old Scotchbright pad. This helps to smooth the surface and add just a little roughness for later coats of paint. If required, I will add addtional layers of primer iafter any flaws are found.