Ammo One Shot Primer issues

[FlashGordon25]

Hi all,

I wondered if anyone had similar issues to mine with Ammo One Shot primer.

The issue being regular clogging of my airbrush. Half way through a priming of a model, the paint stops coming out every so often then not at all. There seems to always be some tip dry right on the end of the needle when breaking down AB to clean. There was also some clogged in the nozzle one time. I’ve played around with psi’s and thinning ratios and adding flow improver, where I’ve felt comfortable laying on the paint but every situation it always the same.
Is it just the paint? Is it worth trying something like a new needle? Or is it putting it down to not getting on with it and trying a different primer? It’s had a new nozzle. It’s a shame as when it goes on correctly it gives a solid finish.

I’m using a Sparmax max-4 (0.4mm)

 

[BarryW]

What size needle?

I have never used One Shot but I did use Stynylrez and I believe that One Shot is white labelled Stynylrez.

I remember that it could be a problem with smaller needle sizes and you need to get the thinning and psi right. I used a 0.4 needle with Vallejo Airbrush Thinner at 50% sprayed at around 25-30 psi.

What you cannot get away from though, as with all water based paint,variables caused by humidity.

This is why I moved entirely over to using lacquers through the airbrush, giving away all my water based paints.

 

[Mini Me]

I'm with Barry on this Matt.........I have been using the same AB for over 25 years and I only use solvent base paint through it....only one needle/tip change in all that time and only one clog. One might call it trouble free. I shoot water base paint through my airless sprayer at 3000 psi. even at that pressure you get clogs, that is why the spray gun has a reverseable tip otherwise you'd be taking the thing to pieces all the time and wouldn't get any painting done. If I seem a little sarcastic, I guess it's because we as hobbyists are literally being forced to use acrylics as more and more lines of high quality solvent based paints are being removed from the industry because some one has a bug up their Ar*se about the environment and smelly stuff etc. Sorry to be so "wordy" but it is a bone of contention with me. Glues will be next!!! Rick H.

 

[Dave Ward]

I've recently replaced my 0.4mm nozzle/needle with a 0.5mm combo. ( this is on my cheapo priming airbrush ), and that seems to be the answer - since I prime overall, I'm not that bothered about spray size. I've shot AK, Vallejo and Stynylrez primers through the larger nozzle, with far less problems than I would normally expect. I try not to dilute the primer ( doesn't always work! ), and spray at about 1.75 bar ( 25 psi ) by my gauge.
Never tried One Shot primer, I'm afraid - but living in a flat, the use of a solvent based primer/paint is not really practical, unless I want to live with the smell...........................
Dave

 

[FlashGordon25]

I'm with Barry on this Matt.........I have been using the same AB for over 25 years and I only use solvent base paint through it....only one needle/tip change in all that time and only one clog. One might call it trouble free. I shoot water base paint through my airless sprayer at 3000 psi. even at that pressure you get clogs, that is why the spray gun has a reverseable tip otherwise you'd be taking the thing to pieces all the time and wouldn't get any painting done. If I seem a little sarcastic, I guess it's because we as hobbyists are literally being forced to use acrylics as more and more lines of high quality solvent based paints are being removed from the industry because some one has a bug up their Ar*se about the environment and smelly stuff etc. Sorry to be so "wordy" but it is a bone of contention with me. Glues will be next!!! Rick H.

Thanks, appreciate the advice. All my paints are solvent based, apart from the ones I use for brush painting figures and tools etc. Just had to try and find myself an alternative in primer. I had wanted to try mr Surfacer 1500 but could not for the life of me find any but I did just find some in stock somewhere so I’m going to try that with some levelling thinners I have. The one shot gives a plastic/rubber like texture when dried on the airbrush which is causing me the issue as this is then stuck in the nozzle and on the needle. I’m forever disassembling the AB and it’s relentless. I don’t fancy taking apart my needle and nozzle every time. So we’ll see how we go with the alternatives, I think the answer is, put the one shot to the back of the drawer for now.

 

[Mini Me]

Hi Matt, that is exactly what it is.......latex rubber, pretty much in all water based paints. It sounds to me you are on the right track, shelving this stuff......you'll have less headaches with your AB down the road. Rick H.

 

[David Lovell]

Thanks, appreciate the advice. All my paints are solvent based, apart from the ones I use for brush painting figures and tools etc. Just had to try and find myself an alternative in primer. I had wanted to try mr Surfacer 1500 but could not for the life of me find any but I did just find some in stock somewhere so I’m going to try that with some levelling thinners I have. The one shot gives a plastic/rubber like texture when dried on the airbrush which is causing me the issue as this is then stuck in the nozzle and on the needle. I’m forever disassembling the AB and it’s relentless. I don’t fancy taking apart my needle and nozzle every time. So we’ll see how we go with the alternatives, I think the answer is, put the one shot to the back of the drawer for now.

Could be a case of one mans poison is another man's what ever they say ,one shot is my go to at the moment i use at about 18psi with a 2 needle thinned fifty fifty or more sixty thinner forty paint never had a problem ,I dont like marmite but love bovril , you have to find what works for you and you alone ,what works for others might not be for you ,hope you sort it soon Dave

 

[FlashGordon25]

Could be a case of one mans poison is another man's what ever they say ,one shot is my go to at the moment i use at about 18psi with a 2 needle thinned fifty fifty or more sixty thinner forty paint never had a problem ,I dont like marmite but love bovril , you have to find what works for you and you alone ,what works for others might not be for you ,hope you sort it soon Dave

Never a truer word spoken. Maybe I could get on with it, but at the moment the grief it’s caused me (and a new nozzle) I’ll pop it to one side for the time being.

 

[Gern]

I shoot water base paint through my airless sprayer at 3000 psi. Rick H.

!!!!

 

[Mini Me]

Dave.......it's for painting houses, not models.......sorry if I misled you. Rick H.

 

[David Lovell]

Never a truer word spoken. Maybe I could get on with it, but at the moment the grief it’s caused me (and a new nozzle) I’ll pop it to one side for the time being.

Hi Matt just a after thought what or who's have you been thinning it with some times certain thinners cause problems ,a lot of them say universal but I'd put doubt on that ,thinners have been much debated on here but to sort paint problems I always think if your using Fred's paint then Fred's thinners is what should be used as a starting point to solving problems.
Oh and I make two three sometimes four light coats with the one shot ,personally slap it on in one go (shot)is being a bit enthusiastic me thinks as I said hope you get sorted. Dave

 

[Gern]

Dave.......it's for painting houses, not models.......sorry if I misled you. Rick H.

Aaahhh. Now I'm with you. I thought it was maybe some sort of misprint for 30.00 PSI - then I thought nobody uses A/Bs and sets the pressure accurate to 2dp. Then I got totally lost!

 

[Mini Me]

The point of using that analogy Dave (Gern) was to illustrate that no matter what pressure you shoot it at water based paint will at some point gum up your paint gun, airbrush what have you.....it is the nature of the material itself. This explains why there are so many additives available to keep it from drying out while using it. The best one can hope for is to get the job done as quickly and efficiently as possible.
Cheers, Rick H.

 

[outrunner]

So it is not just me then.
https://www.scale-models.co.uk/threads/what-am-i-doing-wrong.36969/

Andy.

 

[Mark1]

Lot of people seem to like stynylrez but that's the one I've had problems with, too thick ,tip drying, tried a bit of vellejo airbrush thinner which did no favours,since found out to thin with water! But already changed to vellejo poly primer but not completely sold on it. Still prefer tamiya rattle can, can use a nice thing coat and sticks like s##t to a blanket .

 

[FlashGordon25]

The point of using that analogy Dave (Gern) was to illustrate that no matter what pressure you shoot it at water based paint will at some point gum up your paint gun, airbrush what have you.....it is the nature of the material itself. This explains why there are so many additives available to keep it from drying out while using it. The best one can hope for is to get the job done as quickly and efficiently as possible.
Cheers, Rick H.

It definitely is the case of rushing to plaster it on before it dries in the airbrush and clogs, despite retarder/thinners etc.

 

[JR]

Aaahhh. Now I'm with you. I thought it was maybe some sort of misprint for 30.00 PSI - then I thought nobody uses A/Bs and sets the pressure accurate to 2dp. Then I got totally lost!

I agree Dave , thought Rick had been at the bourbon again, or the thinners .

 

[JR]

Matt I had problems with tip drying, didn't want to use solvent paint as don't want to have to wear a mask anymore as had to at work when spraying cellulose.
I had problem after problem, tried different combinations of mixes, even bought another ab. In the end started to use 3 rd Gen AK paints and bought a Neo ab .
Since then I've had no problems, it had got to the point where I dreaded the thought of using the ab.

 

[Mini Me]

Mine is an absolute dream to operate and it never lets me down. Bought it back in the early 90's.....dual action .....siphon feed. Of course I use those "smelly" non environmental friendly solvent based paints that are slowly being legislated out of existence.....but they get the job done even if I have to look like Darth Vader in the process........."Luke, I'm your father"....etc. Rick H.

 

[boatman]

WELL i think all you guys with A/B have the patience of a saint to put up with usein them as a freind let me borrow his an yes i dont know zilich about A/B 's as i have not used one before but he mixed the paint in the A/B jar an i treid to use it an it was not very good an kept stoppin sprayin an the compressor kept cuttin in an no spray at all an yes i know i make a lot bigger models than what you guys make but for me id rather use the ole rattle cans as ive hardley ever had any trouble with them its just point an spray but yes i understand with a A/B you can spray very small areas an they are very good for that so all you guys have fun usein them but they are not for me but this is just my opinion an im not tryin to upset anyone so have fun with them
chris