What am I doing wrong?

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I got some one shot black primer last week and today I started to prime the Flak gun. All went well for about a minute then it started to splutter a bit and stopped spraying altogether. I thought it was just tip drying so gave the tip a wipe and it seemed OK but only for a few seconds. Having decided that enough was enough I started to clean the airbrush only to find the paint had become a gooey mess inside and it took me ages to clean it, and I mean ages as some of it was so sticky I dug it out with a toothpick. So later on I thought that perhaps the .3mm needle was too small so I got out my other airbrush with a .5mm needle fitted and tried again having thinned the paint slightly with a little water but the result was the same. So, is it me, is it the paint or should I just take up knitting instead? Answers on a fully built and painted model to Useless Eustace, Scotland.
 

AlanG

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What primer was it?
 

JR

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Andy.
No doubt you are using as you have any other Acrylic primer. It does sound strange though has to be the paint.
 

PaulTRose

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if its the MIG One Shot primer, i couldnt get on with it either......went in the bin
 

stona

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Which paint and what did you thin it with?
It sounds like some kind of reaction has produced the gooey mess and I can think of at least a couple of combinations that can do that. I discovered them the hard way!
 

Jim R

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Hi Andy
Gotta be one of three problems. A 'bad' batch of primer, a not compatible thinner or some residue from a previous use of the airbrush.
Very strange though and very frustrating.
Jim
 
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The Smythe Meister

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Hmmmmm,
A very frequent problem......with a myriad of possible solutions,question is........
...... how many will you try,in which configurations,and for how long?!:confused:
This just sums up the reasons why i try and use my A/B as little as possible or even if at all, on builds where i can get away without it!:cool:
Obviously i wish you all the best in sorting out your problem though Andy:thumb2:,
Andy
 
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Mr Bowcat

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What do you clean your airbrush with. Maybe thinner/IPA/cellulose residue reacted with the paint?
 
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What primer was it?
Mig One shot black primer.
Andy.
No doubt you are using as you have any other Acrylic primer. It does sound strange though has to be the paint.
Indeed John, it does seem strange as I use nothing but Acrylics.
if its the MIG One Shot primer, i couldnt get on with it either......went in the bin
Did you have the same problem with it?
Which paint and what did you thin it with?
It sounds like some kind of reaction has produced the gooey mess and I can think of at least a couple of combinations that can do that. I discovered them the hard way!
As mentioned above, it's the Mig One Shot primer and the first attempt was straight from the bottle as it says there is no need to thin. Second time I thinned it with a little water and it was just the same.
Hi Andy
Gotta be one of three problems. A 'bad' batch of primer, a not compatible thinner or some residue from a previous use of the airbrush.
Very strange though and very frustrating.
Jim
I am leaning to a bad batch.
What do you clean your airbrush with. Maybe thinner/IPA/cellulose residue reacted with the paint?
I clean my airbrushes with water and IPA but the second attempt was with an airbrush that had been cleaned and left in it's box for over a month so I reckon any IPA would be well evaporated away.


Andy.
 
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Steven000

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Sounds pretty bad Andy, I ordered some Mig One shot primers to see if they are better than the Vallejo primer I'm using now, but haven't yet got the time to test them out...

I asume it's a bad batch though, as so many seem to like them?
 
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Just had the same problem with Vallejo Metallic Gloss Primer. Sprayed OK for a bit. Refilled cup a splater dash. Changed brushes the same.

Chucked in bin new arrived to day no problem.

Speculating I wonder if I have in using the old lot & not given it a good shake every time I have used it. It has thickened at the bottom.

Now put a couple of ball bearings in the new pot & get her in doors to shake it.

Laurie
 
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Mabye it is a bad batch as I shook the bottle for a long time and did as it said in the instruction label to no avail, time for the bin I think and go back to my old faithful Tamiya.

Andy.
 

Gern

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Only asking Andy, but have you tried Stynylrez? My first attempts with it were not satisfactory as I had problems cleaning my A/B after use. I switched to using IPA as a cleaner and now no problems. Don't use IPA to wipe away dust etc from your kit though. It will fetch off the primer!
 
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David Lovell

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Mig one shot is my go to primer ,bottle says no need to thin didn't know that untill Andy the paint guy pointed it out to me ,I use 50 50 with mr hobby aqueous thinner, depending on how I feel using a 2 my best airbrush or a 3 needle airbrush ,I sometimes go 60 or 70 thinner and have never had a problem ,I fact the only tip drying I've ever had was with Vallejo. It took some time and a few heart breaks but airbrushing is about air pressure and paint consistency nothing else sounds easy to say but once you've sussed it you won't look back. The following pic mig one shot probably 60 thinner 40 paint through a bart sharp 180 sub 30 pound airbrush hands up I had just replaced the needle at I think the awfull price of about 3.50 plus pp just blown on in thin coats not stopping between coats just keeping going till I was happy. The best advice I was ever given was to get a cupboard queen and spend a weekend just trying diffrent air pressures an paint raitios till you've cracked it,I won't get into paint brands and thinners or airbrush cleaners one mans field of daisy's is a nother mans mine field.
Good luck Andy it'll sort its self you wait and see ,your think blimey what was that all about.
20210107_124859.jpg
 

rtfoe

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Using the airbrush is second nature for me. I don't clean it often. I just use a soft brush to remove tip build up. There is less to no build up if I spray without the crown. Haven't changes a needle for ages. Two brushes, one larger needle 0.5 for heavy duty and the other 0.3 for fine spraying. I get better results thinning paint with a larger percentage of thinner over paint. The most I do is 3 coats over each coat while still wet.
The problem you may have is either the tip build up is causing blow back which thickens the paint in the cup or thinner incompatability reaction which starts coagulation or bad batch of paint.
You didn't mention seeing bubbles in the paint cup...this could mean its not thin enough.

Cheers,
Richard
 
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The simple fact is. it should not do that as it says on the label "no thinning needed"so as far as I am concerned it does not work using the information on the label so it is no use to me. What is the point of giving instructions if you have to ignore them?

Andy.
 

David Lovell

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It says 20 30 psi on the lable id say it was that heavy you'd need the 30 just to push it through and atomize it ,as to why it went gloopy? Bad batch just seems like another urban myth surely its produced to a strict formula under factory conditions not knocked up on the kitchen table and bottled by his nan if you were coming to the end of the bottle fair enough ,email mig there usualy very good and have replied to my queries promptly it won't hurt to ask their opinion of your situation.
 
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