GW Paint Primer Issues.

[Brother Pablo]

With my last few batches of models that I primed with GW Primer I have had this issue where the primer is "Bubbling" or creating bumps on the surface.  This does not happen on all of the models in a batch however.  Some get a smooth finish and some get this "bumpy" surface on the same batch.  Some models will also have this on one part and not on another part.  So for instance one leg may have this, but the other may not, and this is all on the same side of the model.  Does anyone have any idea why this is happening?  

As a contrast, I have use Army Painter, P3 back when they were still selling primer, Coat 'd Arms from over 30 years ago, and I have never seen this.  For some models, this may not be a problem, but for others it is.  I can use GW primer on something like Orks, but I don't want that kind of affect for Space Marines for instance.  

Also as a side note, does anyone know what can strip Army Painter primer?  I have used Simple Green, Nail Polish,(Non Acetone) and Alcohol and nothing will strip it.  Do I need go the full Monty and use break fluid?  

[Firedrake Cordova]

Are you able to upload a picture? Part of me wonders whether something like mould releasing agent still on the sprue could cause this? Normally, GW sprays are pretty well-behaved, although aerosols can be finnicky - I assume you followed all of the instructions on the can, and uttered a prayer to the Empreror/Dark Gods/Omnissiah/Four-Armed Emperor?

Edited September 1, 2023 by Firedrake Cordova

[Bryan Blaire]

Brother Pablo, did it only start to happen after you had been using the can for a while on the same day?  Or did it start immediately on the first figure?

 

What was the temperature and humidity % when you were spraying?

[Brother Pablo]

FC:  Most of these are repaints, so I doubt that it is mold release.  I tried to get a picture and it just turns to all black with little in the form of texture.  I already put my most offending miniatures into an alcohol bath to get strip the primer.  Let me see if I can get some paint on to see if it pops out or not.  

 

BB:  More like using the can after a while, not on the first time painting with that can.  Trouble is that some models come out fine in the batch, and some don't.  Temp is between mid 80's to mid 90's depending on when I prime.  Humidity is always below 50% if not closer to 40%.  This is all outside.  

[Bryan Blaire]

At that temperature, you may have paint actually drying as it is propelled to the models, so it starts forming little balls of solid paint in the air, and you get little dried bits of paint causing texture on the surface - IIRC, you get the best spray conditions with a can between 55-75 degrees Fahrenheit with minimal humidity.  It could also be dust and/or pollen, depending on if you are priming in windy conditions.

 

Alternatively, it could also be the can cooling down internally from the propellant if you are using it for a long time causing funkiness with the paint.  Personally, when I do have to use a can of spray for priming, I warm it up a little in a warm water bath periodically right from the start to make the spray more fine in consistency and combat the can cooling down internally as I spray for long periods and the paint thickening up from it.  There are videos on YouTube for this, and be careful - you do not want to turn your spray can into a spray grenade.

Edited September 1, 2023 by Bryan Blaire

[Brother Pablo]

I did prime during Pollen season years ago and I don't think that is it.  The pollen spores were a lot bigger than that, and you could tell that they were pollen.  The self drying may be it, but I am using two different primers these days.  GW and Army Painter, and Army Painter does not have this kind of problems.  I have not had a lot of windy conditions, but a breeze may hit my priming from time to time.  

 

As far as the can cooling, I get two coats on a model at a time, and three rounds of painting to do it.  Short spurts, not long spurts, and once done the can goes back into room temperature.  I may go through two batches of models to prime at a time but that is about it.  Having said that, I don't recall these kind of problems when I am priming in say a garage and keeping the can in the garage between spray.  

[Brother Pablo]

I got some pictures to show everyone what I am dealing with.  It looks like the primer "melted" the model in these parts of the model.  None of these models had this rough texture when I initially primed these models, nor is it on all of the model.  It is in parts to a varying degree.  Does anyone have any idea why it is doing this?  

[Bryan Blaire]

That very much looks like the effect of paint drying in the air in little balls/clumps before hitting the surface of the model, and then the spray filling in around it.  The temp was likely too high to be spray priming from a can at the distance you were at.

 

My two suggestions in this instance would be:

1) Don’t prime with a spray can over about 75 degrees Fahrenheit.

2) If you do, get closer and use light bursts, start spraying before you hit the model, and stop after you pass the parts you are spraying - do it in one smooth sweeping motion.  Then make sure your spray nozzle is very clean with each pass, so the spray isn’t picking up drying gunk as it flows out and splatters that on your models too.  Stay out of direct sunlight, and prime early in the morning or near sundown, so the temps are naturally cooler.

 

I always try to follow #2 suggestion no matter the temp.

Edited September 23, 2023 by Bryan Blaire

[Grotsmasha]

I agree that looks like drying paint. I'd recommend spraying not under direct sunlight, and if it's got out, spraying a little closer to the model than usual, or wait for it to be cooler in the early evening.

[WrathOfTheLion]

Depending on your region, you may want to spray during the middle of the day and not the evening. In the Southeastern US, it gets really humid once evening/morning start hitting (usually 80-100%), so those can be bad times to prime.

 

So even if it's hotter during the middle of the day, it can be better to do airbrush/rattle cans here then.

 

One thing to do if things are less than ideal, is you can spray a lighter coat and come back in a second time once it has dried if you missed some. That can be better than putting too much at once.

Edited September 23, 2023 by WrathOfTheLion

[Brother Pablo]

I am the next state north of WrathOfTheLion so I have some of those environment problems.  I would admit that these models were primed during the summer out in the heat,(but in the shade) so that was my mistake.  However, I have primed in the past during the summer, and I have not had this kind of issue.  I am thinking of getting an airbrush station that vents all fumes out into the outdoors for more than one reason, but this may be one of them as well. 

 

Originally I was thinking that it was not dried primer particles, as all of these bumps looks like it was part of the model it was that close to being gray.  Then I took a file to the marine above and not only do the bumps go away very easily but the gray is noticeably different from where I file.  Looks like you are right.  It seems that I need to give these guys a few more baths in my stripping solutions to get all of these particles off of my miniatures.  Good news is that I don't think that I ruined the models, bad news is that I need to figure out how to remove them from my miniatures. Thanks for the help.  

 

As a Side note:  WrathOfTheLion If you are looking for another opponent, PM me and let me know where you are at in SC, I live near the Border in NC so I may be in your neck of the woods.