Vallejo Surface Primer "problem"

[NiceGuyAdi]

I've started running Vallejo primer through my airbrush. I've read a few comments around that it's no good, and that it scratches off very easily.

 

Sure enough, with only a little pressure from a fingernail, I've found this on the latest batch I've primed, which I'd left for several days to cure.

 

What I wonder is: is this a problem? Is the primer just a "tooth" layer, for the acrylic paint to bond to, or should it be tough enough to take some abuse?

Edited April 16 by NiceGuyAdi
additional info

[Firedrake Cordova]

I suppose the obvious questions are: is it likely the model had any surface contaminants on it which may have prevented bonding, was it fully mixed, and how thick was the primer layer?

I use Vallejo's surface primer through an airbrush, and can't say I've not had a problem with it. I know that at least some historical modellers use the Vallejo primer and sand it without issues.

 

I don't know if Miniac and MiniJunkie's videos are helpful or not?

Edited April 16 by Firedrake Cordova

[NiceGuyAdi]

Those videos are helpful. It's likely because I'm thinning the primer. MiniJunkie was saying he sprays at ~40psi, but my cheapo brush only goes to ~20psi (and that's what the manufacturer says).

 

I'll give another go of priming undiluted, but if that fails because it's clogging, then it looks like I'm back to car primer in rattle cans.

[Firedrake Cordova]

If it's any help, I add some flow improver to prevent clogging and spray it at ~1.8bar with a 0.4mm (H&S) needle. I try to get a reasonably thin coat on, and then go over it again.

[andes]

I stopped using Vallejo primer for this reason... I just found it too unreliable. I know many people swear by it but I've been let down too many times. I'm using Stynylrez now, but recently picked up a bottle of Monument to experiment with.

[Bryan Blaire]

I’ve had similar results with Vallejo primer as well.  I would wash the plastic with soap and water, dry it thoroughly, and then assemble.  No matter what, the Vallejo would peel off with just a bit of rubbing from a finger or nick with a nail, usually on prominent parts of the model.

 

Like andes, I also made a switch to Stynylrez and Monument Hobbies.  I found the Stynylrez was also rubbing off by itself, so I’ve found the best results for me have been a thin primer coat, then a thin matte varnish coat, then another thin primer coat - this seems to either become tough enough or just has enough layers that rubbing/nicks don’t seem to appear.

 

I can’t say if the Monument primer is any better for single coat applications because I’ve taken to applying all my airbrushed primer coats in the above fashion, but no matter what, it works for me and I’m not seeing what I would consider loss of detail, so I am likely to keep doing it.

[andes]

I think airbrush primers are more delicate by nature. My models don't see a huge amount of table time so I'm fine with it, but if I'm painting terrain I always use rattlecan primer.

 

One of my favorite things about Stynylrez is the dry time. It's ready to take paint after ~20 mins.

 

Edited April 16 by andes
Department of Redundancy Department

[Ayatollah_of_Rock_n_Rolla]

Yes, acrylic primers are more delicate by nature. The main reason people use them is the same reason, why people use acrylic paints for airbrush - less irritating in not so well ventilated spaces.

[NiceGuyAdi]

So much useful info comes out of this place. Thanks all.

On 4/16/2024 at 3:01 PM, Firedrake Cordova said:

If it's any help, I add some flow improver to prevent clogging and spray it at ~1.8bar with a 0.4mm (H&S) needle. I try to get a reasonably thin coat on, and then go over it again.

Just by way of update: Switching from using airbrush thinner, to airbrush flow improver, with the primer has made a massive difference both in coverage and usability without it clogging.

[Firedrake Cordova]

Good to hear