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I've recently got the white one to put through my airbrush. My problem with it is, it's so easy to peel it off. The slightest scratch and it's like peeling a large bit of dried glue, or a layer of wrapping off the model. Is it supposed to be like that?

dwfait wrote:I've recently got the white one to put through my airbrush. My problem with it is, it's so easy to peel it off. The slightest scratch and it's like peeling a large bit of dried glue, or a layer of wrapping off the model. Is it supposed to be like that?

did you clean the model before painting??

dwfait wrote:I've recently got the white one to put through my airbrush. My problem with it is, it's so easy to peel it off. The slightest scratch and it's like peeling a large bit of dried glue, or a layer of wrapping off the model. Is it supposed to be like that?

Can you link the primer you're using? The only primer I use now is Vallejo Model Air Gray Primer, and I'm not getting the effect you're talking about.

ruff wrote:

dwfait wrote:I've recently got the white one to put through my airbrush. My problem with it is, it's so easy to peel it off. The slightest scratch and it's like peeling a large bit of dried glue, or a layer of wrapping off the model. Is it supposed to be like that?

did you clean the model before painting??

Yes, with warm soapy water and then left them to dry completely. I did 10 Terminators and a dreadnought with it and they're all the same.

targetawg wrote:

dwfait wrote:I've recently got the white one to put through my airbrush. My problem with it is, it's so easy to peel it off. The slightest scratch and it's like peeling a large bit of dried glue, or a layer of wrapping off the model. Is it supposed to be like that?

Can you link the primer you're using? The only primer I use now is Vallejo Model Air Gray Primer, and I'm not getting the effect you're talking about.

http://www.acrylicosvallejo.com/gb/primers-gb.html

The surface primer at the bottom.

The vallejo PU primers take a while to cure fully. Best left overnight before attempting to work on them.

You should also use a higher PSI when shooting the Polyurethane Primers through your airbrush. A dusting should be enough, so that the paint will have a nice surface to adhere to.

Cheers,


IK-Painter

winterdyne wrote:The vallejo PU primers take a while to cure fully. Best left overnight before attempting to work on them.

Yes, someone else had this problem recently, it was fine after 24 hours of curing

Thanks. A quick question to those who use a grey primer though - I find it's pretty much the same colour as the plastic. How do you know when you've gone over an area or not? Or if you've missed an area? I have the air grey primer, and I find it pretty much useless as I can't tell if I've primed or not.


Edit: Also, what's a good PSI to work at? I have a dual action, internal mix gravity fed airbrush. Around 20 PSI sound ok?

dwfait wrote:Edit: Also, what's a good PSI to work at? I have a dual action, internal mix gravity fed airbrush. Around 20 PSI sound ok?

I think that's a tad on the low side - I use between 45-55 psi for priming.

IK-Painter wrote:

dwfait wrote:Edit: Also, what's a good PSI to work at? I have a dual action, internal mix gravity fed airbrush. Around 20 PSI sound ok?

I think that's a tad on the low side - I use between 45-55 psi for priming.

Hmm. I did have it up higher, but I got a bit of spluttering and spitting.

I run the PU through a .3mm nozzle at about 30-35psi.

Ok. And just a light dusting.

I have a .35 mm nozzle so it should be fine.


Anyone else have any tips on using a grey primer? Can you tint it with a little bit of a colour paint so you can see where you've hit the model with primer?

Ok, it's been a couple of days now, and I seem to be able to still scrape away the primer with my nail so easily. Do I have a bad bottle or am I just using it wrong?

Pics would help. The primer does come off reasonably easy (especially off metal), but I usually get good adhesion on plastics. Not sure what's going on.

I use these primers and I really love them. I have 9 colors.
They spray like a dream, no thinning, just use straight
out of the bottle. I spray at about 18 psig through a .2mm
nozzle. It is a very thin coat of paint, and can rub off if not properly handled. Once cured it is pretty tough. I recently
stripped a metal model that I had previously used the gray
primer on, I was surprised to see that even the Super Clean
solution left some of the primer on. I even scrubbed with a toothbrush and was unable to get down to bare metal, usually I get a shiney metal model after doing this process.
I've started collecting all of the Vallejo model air line
of paint.

I suggest you use Krylon Primer, it works well in the right weather conditions and comes out great.

I've attached a picture. It starts to just peel off like Latex paint.

Maybe I've put it on too thick?

dwfalt - any update on this? I recently tried using the Vallejo Black Polyurethane primer, shooting at 30PSI with a 0.3mm needle. I found that it covered beautifully, didn't obscure details, but even after waiting a week, the primer was still quite easy to scrape off with a light fingernail press.

Let us know if you figured anything out

P.S. I also purchased the Grey primer, and only used it once. I found that it came out a little too watery (I used it straight out of the bottle) - maybe I didn't shake it up enough first? It was more difficult to get good coverage when it was like this.

That Dreadnought has been sitting on my desk since I made the post. It still scratches off pretty easily.

The termies, I've been painting up. I figure, just be careful, and varnish them when done to protect them.

I painted a portion of the Dread, and for what its worth, it seems to be quite a bit more resilient to scratches.

I'm going to try coats of very thin layers of primers, giving them plenty of time to dry, before I put the next one on soon. I'll post how that goes.

This may help.....(It happened to me)

http://www.dakkadakka.com/dakkaforum/posts/list/423489.page

Don't expect to have the same results as a spray can primer, which has some pretty nasty (but effective) chemicals in it and doesn't have to be cleaned out of an airbrush when it's gone. Airbrush primers just are not going to hold like spray can primer.

The goal here is a) for it to be hard enough to not rub off and b) give later coats something to grab on to. But you are expected to seal when you are done painting, it shouldn't have to deal with scratches during the painting process.

It it is rubbing off while being handled you might have a problem. If it requires you to scratch it with your fingernail then that is about the best you can hope for.

Just prime, paint, then seal with varnish. The varnish is what is going to protect your mini from scratches.

riplikash wrote:Don't expect to have the same results as a spray can primer, which has some pretty nasty (but effective) chemicals in it and doesn't have to be cleaned out of an airbrush when it's gone. Airbrush primers just are not going to hold like spray can primer.

The goal here is a) for it to be hard enough to not rub off and b) give later coats something to grab on to. But you are expected to seal when you are done painting, it shouldn't have to deal with scratches during the painting process.

It it is rubbing off while being handled you might have a problem. If it requires you to scratch it with your fingernail then that is about the best you can hope for.

Just prime, paint, then seal with varnish. The varnish is what is going to protect your mini from scratches.

The vallejo Poly primer should be pretty damn tough, i can only just scratch it off with a finger nail on my models even if i work at it

I have definitely heard some claim similar experiences in finding it extremely tough. I've been through a few bottles myself and never had it that tough, and I know through researching it online there are many others with experiences similar to mine, and that was the advice I got on the subject.

Climate could come into it or some other factor. I'm not sure why it works so well for some and not others.

The main point is, it doesn't HAVE to be varnish tough. As long as it isn't rubbing off and it is giving the paint a good surface to adhere too, it is doing its job fine.

Thank you riplikash for the additional information - it helped make me more confident in the results I have been getting with this primer You are correct in stating that as long as it's not coming off with general handling, it's doing it's job, which is indeed the case for me.

It makes sense that spray can primer vs. airbrush priming would each have pros and cons, and as long as this airbrush primer does the job in the end, I'm willing to live with the minor con of it being less resilient initially. Not having to put up with the awful smell of spray can primer is worth it alone, not to mention the control and thinness of the airbrush primer

Thanks also Lovepug13 - I will have a read through your post as well!

THe other thing to remember is that primer is not meant to fully coat the model. You are priming not painting. Most people use WAY too much primer and don't know it, be it rattle can or airbrush. You want some of the plastic/resin underneath to show through. If you paint the model in primer you are just trading one smooth surface for another. What you are looking for is simply something to give a very slightly rough surface (tooth) for the paint to adhere to. That is the only purpose for primer.

So I would say give that a whirl and see if that helps.

Synchro wrote:THe other thing to remember is that primer is not meant to fully coat the model. You are priming not painting. Most people use WAY too much primer and don't know it, be it rattle can or airbrush. You want some of the plastic/resin underneath to show through. If you paint the model in primer you are just trading one smooth surface for another. What you are looking for is simply something to give a very slightly rough surface (tooth) for the paint to adhere to. That is the only purpose for primer.

So I would say give that a whirl and see if that helps.

Sorry if this sounds harsh, but that is really bad advice. Primer is meant to fully coat the surface. If you apply it properly, using puffs, it will form a super thin coat that does not obscure detail.

You are not just trading one smooth surface for another. The goal of priming isn't to 'texture' plastic, at least not in the way you are thinking. Primer is chemically formulated to a) stick to surfaces better than paint b) allow paint to stick well to it. Paint will stick will to a solid coat of primer, after all, primer was designed for that purpose. Spotty coverage is just going provide unwanted texture and give flaking a good place to start.

TL;DR you do want to coat the whole mini, but with a very thin layer. Paint sticks to primer. Don't go for patchy coverage.

Perhaps I mispoke but you and I are saying the same thing from what it sounds like. My point is that I see many many people literally coat the miniature thick so that it is wet and dripping. which is what I meant by painting it. Your description of puffs of microfine layers is a much better description and what 90% of people I see do not do.