Alternatives to PU primers

[Jagdtiger1]

Hi all,

 

After struggling away with a bottle of grey mig one shot primer (badger stynlrez/UMP all the same useless stuff), I have gone off all PU based acrylic primers.

 

So the question is, does anyone know of decent non-PU acrylic primers for airbrushing?

 

I've got some halfords spray paints which could be decanted, but looking on here, people are saying that they should be thinned or cleaned with cellulose thinners?

 

Then I've found AKs new primers although it says "water soluble" and "non-toxic", which to me screams PU based.

 

If there aren't, then it'll be time to invest in lacquers, presuming hiroboy's zeropaints aren't acrylic.

 

Thanks,

 

James.

[psdavidson]

I've never had much luck with acrylic primers, no matter what I do. Others seem to get along fine with them

I currently use rattlecans but don't decant, just straigth from the tin. It's not the best but good enough for me.

If you head towards laquer-based, the Hiroboy primer is nice, but you could also consider Mr Surfaces and Mr Levelling thinner which is likely to be more cost-effective.

 

/P

[Tojo72]

I use Tamiya or Mr Surfacer 1200 in the rattlecan,I will usually step out on the walkout of my basement for a quick shot.

They level out nicely,never puddle or obscure details.

[Jagdtiger1]

Thanks psa and Tojo,

 

I actually recently used my halfords straight from the can on my build of a 1/350 new jersey, my only problem was that it comes out at a fair rate of knots! It also dried fairly rough on such a large model, but nothing a light sanding can't take care of, easy to do on a huge warship but not so easy on all the tight spots of a centurion.

 

On that same build I used tamiya spray cans for the haze grey and went through 2 and 1/2 cans, I can't really decide if they have good coverage or not.

 

James.

[Casey]

Do they publish the SDS'es to their products?

 

I have no problem with PU primers. The main factor for me was understanding that drying time for PU is hours but curing is MUCH longer. If anything I would compare them to PU floor finishes - and it takes up to 30 days to fully cure them.

[Mark Harmsworth]

I am interested in this - but for the opposite reason. I've been using Ultimate primers for several years. Thinned with their thinners and sprayed at just under 20psi using a wide nozzle it gives a robust, smooth  surface.  I'd be interested in hearing how you've been trying to use it.

 

Good luck with your search.

Mark

[Jagdtiger1]

Thanks Mark,

 

Since coming back to modelling I've used PU primers on 3 models. I can somehow make them work, its just a lot of effort. I try one thing once and the next time it just won't work. Today I was spraying at 20-30psi with a 0.5mm needle. I can't remember if I ever thinned it in the past, and using UMP cleaner to clean up. The one thing I have found is to NEVER add IPA to it. I did that once and the primer gummed up on contact, that completely ruined the airbrush.

 

I never tried thinning it this time as I just read off the bottle because I'm honestly too lazy to bother sometimes!

 

I'll try thinning it with UMP thinner tomorrow, out of interest what ratio do you thin at?

 

Thanks Casey,

 

Never heard of an SDS before, google only takes me to the demon's lair called skills development scotland unfortunately.

 

My experience today was that it was both drying and curing VERY quickly, abnormally quickly compared to how I've seen before. The inconsistency in its behaviour is the most offputting feature.

 

James.

 

 

[Casey]

8 minutes ago, Jagdtiger1 said:

Thanks Mark,

 

Since coming back to modelling I've used PU primers on 3 models. I can somehow make them work, its just a lot of effort. I try one thing once and the next time it just won't work. Today I was spraying at 20-30psi with a 0.5mm needle. I can't remember if I ever thinned it in the past, and using UMP cleaner to clean up. The one thing I have found is to NEVER add IPA to it. I did that once and the primer gummed up on contact, that completely ruined the airbrush.

 

I never tried thinning it this time as I just read off the bottle because I'm honestly too lazy to bother sometimes!

 

I'll try thinning it with UMP thinner tomorrow, out of interest what ratio do you thin at?

 

Thanks Casey,

 

Never heard of an SDS before, google only takes me to the demon's lair called skills development scotland unfortunately.

 

My experience today was that it was both drying and curing VERY quickly, abnormally quickly compared to how I've seen before. The inconsistency in its behaviour is the most offputting feature.

 

James.

 

 

SDS is Safety Data Sheet, it gives exact composition of the stuff and is required by a lot of countries. You may need to ask the company but they should be public. I have got SDS'es for Tamiya that even include detailed pigment compositions of their paints.

[Casey]

On a funnier note, you may wish to look at:

 

MIL-STD-2161C, DEPARTMENT OF DEFENSE STANDARD PRACTICE: PAINT SCHEMES AND EXTERIOR MARKINGS FOR US NAVY AND MARINE CORPS AIRCRAFT

 

It specifies MIL-PRF-85285 to be used. This is an PU based coat.

[armored76]

Hi,

 

Reading your entries, I understood, you have problems with getting yours to spray properly? Is that right? I tend to thin mine about 50-50 and I recently switched back to the Vallejo range and love the rubbery finish.

 

Other than that H&S airbrushes are known to misbehave with acrylic paints and primers but I got mine to work decently with a 0.4 nozzle. Haven't tried larger ones but it might further improve the results. The smaller 0.2 nozzle was working but required a lot of patience.

 

I steered away from non-acrylic paints and primer in general due to their smell, mainly. Before that, the MRP primer (the very light grey, almost white one), straight out of the bottle was like magic potion.

 

Hope this helps!

[Dunderklumpen]

On 6/27/2022 at 7:00 PM, Jagdtiger1 said:

Thanks Mark,

 

Since coming back to modelling I've used PU primers on 3 models. I can somehow make them work, its just a lot of effort. I try one thing once and the next time it just won't work. Today I was spraying at 20-30psi with a 0.5mm needle. I can't remember if I ever thinned it in the past, and using UMP cleaner to clean up. The one thing I have found is to NEVER add IPA to it. I did that once and the primer gummed up on contact, that completely ruined the airbrush.

 

I never tried thinning it this time as I just read off the bottle because I'm honestly too lazy to bother sometimes!

 

I'll try thinning it with UMP thinner tomorrow, out of interest what ratio do you thin at?

 

Thanks Casey,

 

Never heard of an SDS before, google only takes me to the demon's lair called skills development scotland unfortunately.

 

My experience today was that it was both drying and curing VERY quickly, abnormally quickly compared to how I've seen before. The inconsistency in its behaviour is the most offputting feature.

 

James.

 

 

I have a similar story, and at the same time completely different. Bear with me!

 

Since returning to the hobby a few years ago, I’ve invested in an airbrush and compressor. I tried a few primers from Vallejo and Ammo, but I never liked them. Tip dry and all sorts of strange behavior. But when I switched to UMP everything straightened out for me. I spray them neat from the bottle at recommended psi with their “own’ airbrush, both 0.35 and 0.5mm needles. Works beautifully! The thing is to shake the living daylights out of them! I have dropped a few agitator balls in the bottle and use a vortex mixer. No problems anymore!

 

Out of curiosity, Mark, how much do you thin and with what?

 

Happy modelling!

 

[Mark Harmsworth]

On 27/06/2022 at 19:00, Jagdtiger1 said:

out of interest what ratio do you thin at?

Good question. I use their thinners but not to a specific ratio I'm afraid. I mix in a separate container (never the airbrush cup) and add a few drops of thinner. The only helpful point I can add is that I don't thin primers quite as much as for acrylic paints. For paints (xtracrylix, tamiya etc) I thin down to the point where it looks like skimmed milk.

 

Very unscientific I'm afraid.

Mark