Primer problem?

Hey guys,

I made my first test with the primer and I’m having grain on my model. I don’t see it at the naked eye, but on photos with a good lighting it shows. Do you know if I’m doing something wrong? Here’s also my primer.

If by “grain” you mean an “orange peel” like surface texture, that’s usually due to overapplication of the paint. Try more lighter passes and give the primer a few minutes to set between passes.

Yeah thats what I mean.

Could you give me numbers? Like own many spray stroke do you do by angles for a first pass and own long do you wait?

Or maybe a tutorial video?

I got a “lazy Susan” and did quick bursts to help solve that issue for me

Make sure you aren’t too close, do a light coat and then let it dry for 15 minutes and then do another and repeat until it’s enough

@Zachary_Brackin Can you define light coat? How much sprays per angle let’s say? And how much (very approximately) is enough coats?

Do a couple swipes and then rotate a bit. It’s enough coats when it looks like you’re just seeing the primer and not the resin.
You can also use a micromesh cloth to smooth it afterwards:

It is very hard to prime such a model with much details and hollows with a spray can.

It’s better and easier to prime (and varnish) with an airbrush system (compressor and double action pistol). Even the cheapest airbrush equipement shows better results than a spray can.

@JohnK42 Do you have a suggestion for a cheap airbrush?

@Zachary_Brackin Do you use the micromesh cloth between each coating or once at the end?

You would use the micromesh after the primer is dry–you can possibly use it on that part you already printed to smooth some of the issues with the primer. Primer dries pretty quickly but it’s best after you’re finished to let it fully dry for a day before painting

I’m living in Europe, so it’s hard to say which airbrush is available in Canada.

Look for a double action pistol with a paint tank on top (e.g. at Amazon), cheap pistols start at EUR 35 / CND 25, and a membrane compressor (cheap, silent and maintenance free). If the compressor hasn’t an air tank, look for a long air hose (min 1.5 m).

Better pistols with better quality and available spare parts start at EUR 100 / CND 70, better compressors are piston compressors with air tank.

Hope this helps.

You should be able to do it just fine with a rattle can, you just need to be patient. Light coats (meaning 25+ cm away. Start and stop the can when it’s not pointed at the model. If you don’t have a lot of overspray you’re not doing it right), which will dry quickly (a few minutes). Don’t worry if you don’t get full coverage on each pass. Trying to ensure you’ve hit every surface the first go around is a fatal trap. That’s how you end up with too much in some areas. Each pass, try to even out the areas that don’t have good coverage from the previous pass.

@Zachary_Brackin What exactly is a micromesh? I read somewhere the finest sand paper can also be used between coats right?

@Randy_Cohen I followed your instructions and it seems to help. I still can see grain tho. I might #1 be too picky, #2 not doing it right still, #3 might need to sand it a bit between coats maybe.

I can’t show a full picture of my new test yet as there is an NDA on it. Can’t wait to show the final results, but in the meantime here is a close-up. Note that I’m aware a few bumps are actually dust speckles (I have to prime outside on my balcony cause I don’t have space inside) but I’m talking about the grainy surface that is everywhere. And trust me, with a bright light, the grina REALLY pop out!

What are you thoughts?

Unless you live in the Antarctic, the outside air is going to be so full of dust that I doubt you can do much better. Especially so if you live in a city. If you live anywhere in the northern hemisphere, there is an incredible amount of pollen in the air right now. It’s not just what sticks to the paint after it’s on the model, but the atomized paint coming out of the sprayer is going to clump around any particulate it encounters between the can and the model.

That being said, if this is primer it looks like you may be applying it a bit too thick. You could try backing away a bit more with the rattle can. But you can’t do this outside. If you live in an Apartment and it has a bathroom with an exhaust fan, you could make a spray booth with some sheet plastic tarp-like material and use the bathroom exhaust fan as the vent for the “booth”…

@Randy_Cohen Are you saying the grainy surface (not talking about the speckles of dust) is due to the dust in the air outside or that’s solely caused by me laying too thick of a coat between layers? If you think it’s spraying outside that might cause this, I can try to make a panel and do it in my bathroom… gonna be a challenge because I got a super narrow bathroom.

It looks like you may have been spraying too much again. The thing about dust is that dust may stick to the paint, so if you can, try and cover it while it’s drying to protect from dust.

Micromesh is like a sanding cloth but they are very fine to where you can polish a part to be very smooth and reflective (can be used with Clear resin to make it very transparent instead of frosted)

Do you have any specific recommendations for makes or are they all about the same?