Ammo One Shot Primer

[Weedlesketch]

I have recently attempted to use the Ammo One Shot primer on a T34 build. During some test sprays on spoons I had great success. Laying down light layers produced a nice, smooth, opaque finish that stood up to sanding after curing overnight... despite the primer seeming a little thick out of the bottle it seems to go through my H&S Ultra 0.4, at 20-25 PSI with no issues.

 

However...

 

Upon moving trying on the model I barely managed to put a light coat on a rear quarter before I started to get splattering and clogging. This was more than a little tip dry. The nozzle was becoming thoroughly clogged and a deep clean was required to clear it out, even needing to resort to the reamer and brushes in the H&S service kit.

It too me 3 cycles of spraying/cleaning to get a coat on the model and unfortunately it has dried quite rough. My diagnosis is that the primer is too thick, and the high PSI is causing it to dry before hitting the model... so I have 2 questions...

 

1) Is my diagnosis reasonable?

2) What have people had success thinning One Shot primer with?

 

I have been using Mr Surfacer as a primer in the past (with mask and booth), but I am keen to limit putting nasties into the air as much as possible for the sake of kids/pets lungs and Stynylrenz/UMP/One Shot seem to be considered the better end of acrylic primers.

 

Ta in advance.

[dromia]

I find it needs spraying at high pressure in my experience, I go at 30-35psi in my Mr Hobby .5 airbrush.

 

I am a devoted enamels and cellulose paint user but I am happy to swap 'tween MrSurfacer and Stynlrez for priming as Stynlrez when down behaves as well as an enamel or cellulose primer.

 

Interestingly I have a bottle of the UMP branded Stynlrez and that appears to have gone "off" it has lost it sticking ability, won't feather when sanded and just peels away like all the rest of those pathetic water-based "acrylics". The real Stynlrez which is as old as the UMP stuff still works as advertised as does the One Shot I have but that is newer about a year old.

[Weedlesketch]

1 hour ago, dromia said:

I find it needs spraying at high pressure in my experience, I go at 30-35psi in my Mr Hobby .5 airbrush.

 

I am a devoted enamels and cellulose paint user but I am happy to swap 'tween MrSurfacer and Stynlrez for priming as Stynlrez when down behaves as well as an enamel or cellulose primer.

 

Interestingly I have a bottle of the UMP branded Stynlrez and that appears to have gone "off" it has lost it sticking ability, won't feather when sanded and just peels away like all the rest of those pathetic water-based "acrylics". The real Stynlrez which is as old as the UMP stuff still works as advertised as does the One Shot I have but that is newer about a year old.

What sort of distance do you spray it at with that high a pressure?

[dromia]

2"-3".

 

Any further and it dusts.

[Weedlesketch]

Thanks dromia. Increasing the pressure as you suggested worked a treat 👌

Edited October 14, 2021 by Weedlesketch