Problem with gritty base coat

[Drudge Dreadnought]

I just spray-primed some models with GW primer. However, the coat seems to have gone on a bit gritty. In some places they are just fine. In other places, the surface is more like fine sandpaper. What caused this? I had cleaned the models first, so it was nothing left over from the molding process. I sprayed them indoors in a room-temperature room, under the exact same conditions that have I have primed some 5000 pts of models before with no issue. The only thing I can think of was that the can was nearly empty, but I've sprayed cans till they were empty before without problems.

 

Is this a common problem? Are there any suggestions to fix it?

[winterdyne]

It happens now and then - generally the grittiness is due to the paint drying before it hits the model (the particles don't then level). You can try sanding down large, flat ares, or brushing on a little solvent (tamiya thinner has helped me in the past). If it's really bad, the only thing to do is strip and start again. :)

[Drudge Dreadnought]

Arrg, that's what I was afraid of. I had the models in pieces when i sprayed them, and it only seems to have affected some of the bits as I didn't spray them all at the same time. So i guess it isn't a big deal to just strip the few parts that it's a problem on.

[Tanhausen]

I sprayed them indoors in a room-temperature room

 

[silent]

 

[still silent]

 

[holding his breath]

 

:unsure:

 

The "sand paper effect" is usually due to:

 

1.- Spraying too close

2.- No having shaken enough the can

 

However, if you've already sprayed a bit like you said... you must have done something different.

 

Note: sorry for the quote... but what other kind of temperature would you get in a room? xDDDD

[Drudge Dreadnought]

I sprayed them indoors in a room-temperature room

 

[silent]

 

[still silent]

 

[holding his breath]

 

:unsure:

 

The "sand paper effect" is usually due to:

 

1.- Spraying too close

2.- No having shaken enough the can

 

However, if you've already sprayed a bit like you said... you must have done something different.

 

Note: sorry for the quote... but what other kind of temperature would you get in a room? xDDDD

 

I've been spraying under the exact same conditions for a good 2 years now :/

 

And I've never really understood the phrase either.

[winterdyne]

I paint in a conservatory. It gets silly hot in summer. Winter not so bad as I'm allowed to run a heater...

[Tanhausen]

I understand the "room-temperature" concept (which usually translates into "nothing extraordinary").

 

I just found funny that you specified that your room is usually at room-temperature xD Nothing more... just laughing a bit :)

 

BTW, some materials do need specific conditions such as humidity or temperature.

 

When for example using Silicone... you can get RTV: which stands for Room Temperature Vulcanization. What it means is that it doesn't need special conditions (temperature in this case) for curing.

 

Anyhow, I think you got pigment flakes like winterdyne said. Origin? Probably due to lack of can agitating. Solution? Alcohol is your friend: soak it for a while (couple hours should be fine) and then rub it with an old toothbrush. If you are not concerned about posing/paint/greenstuff or whatever, just go for paint stripping as usual.