Group,
This has been driving me crazy. I have just started using this out of the bottle and I keep getting little white spots on my models. The come off but it is really annoying. I have a Paasche Airbrush and I have cleaned it several times thinking I am getting some contamination from something else but I only ever get white. I just sprayed tuscan red the time before I did the dullcote. And I still got white spots! Could I have a bad bottle of paint?
Thanks
Sam Vastano
Could be possible the bottle is contaminated, though unlikely.
Are you using a propellant can, air tank or small air compressor?
If it's an air tank or compressor, could be oil in the air. Easily solved with a moisture trap. I don't know about propellant cans though.
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Compressor. It might be something in the air but wouldn't I see it in the colors too?
I would assume your using enamel paint? Enamel covers up some blemishes on its own and fills them in. The dullcote also doesn't have any pigments (I sure hope not) that might cover the blemishes. If you see the same thing in the colors, you really got a problem.
Have you used alcohol either to thin your paint or on the model itself? Alcohol and Dullcote react to make a light haze. I use a combination of alcohol and water to thin acrylic paints for my airbrush and sometimes I still get that reaction. Another shot of Dullcote might clear that up.
Another thing you'll want to do when it's cold is sit your can of Dullcote in a pan of hot water for a while (hot from the sink, but never heated on a stove lest you cause an explosion). This assures the Dullcote atomizes completely when it leaves the spray nozzle.
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I am not using thinner for the Dullcote strait out of the bottle. I notice that when the Dullcote sits it separates into a clear liquid and a really nasty looking yellow haze. I shake the bottle to get them to mix but still looks nasty to me. As for the other paints I use. Yes Enamels I use Scalecoate I as my primary colors. I never see any fish-eye from contaminates from the compressor. I have painted cars so I know what oil looks like when it gets into the paint on a car. Nice little dimples. This stuff looks like somebody splashed white paint on the model. If you let it dry you can remove it with a fingernail easily but it is driving me crazy.
Sam
I've never had any success shooting bottled dull coat straight from the bottle without reducing it - it's way too heavy. Try thinning it with some Testors reducer (or even lacquer thinners).
I'd almost bet that will cure your trouble. That sediment in the bottle is nothing more than talc. Trying to spray it straight out of the bottle that thick will give you an occasional spatter which will dry as a white spot due to the concentration of talc in that spot.
Mark.
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Thanks! That sounds reasonable. I will try it! Merry Christmas!
I do thin the dullcote 50/50 with lacquer thinner and still get the occasional white spot. I don't know what it is; I've just learned to live with it. Like was said earlier, they are easy to remove and I just spray another coat.
The white blush is caused by one or a combination of three different things.
1) temp / hunidity, moisture
if the model, room temp, or dullcote are too cold, the dullcote will attract moisture and blush.
If you are using canned propellent, sit in a bowl of warm water, or run hose thru to keep temp up, as the gas expands it gets colder.
If using a compressor, make sure you have a functioning moisture trap.
2) Dullcote not mixed properly, the talc will settle and spatter if not completly mixed
3) alcohol, will cause the talc to come out of suspension on the surface of dullcote and force blush, and can actually be used as an effective weathering techinque.
since the alcohol forced blush is on the surface, it will disappear with another misting of dullcote.
example of both moisture and forced blush. nearly all weathering done with dullcote blush
I intentionally wanted the overall chalky blush for this model so I put in the freezer for about 20 minutes before dullcoting it.
The I went back with a paint brush and alcohol to hit the areas that I wanted heavy water scaling and misted alcohol where I wanted the dusty look.
What River Eagle said...Temp and humidity. Definately thin with lacquer thinner too.
I've had this same problem with rattle can dull coats too so it's not a compressor/oil/water filter problem.
You can also respray it with a thin coat of glosskote from Testors and then respray it with the dullkote.
This has worked for me.
Carey
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I always mix in a little glosscote with the dullcote - and thin it like said above... you will have to experiment to find the amounts, but I think I was using 1 part glosscote to 8 parts dullcote - it doesn't take much to get rid of the chalking problem you are getting - and it doesn't make it glossy at all...
Also - you can spray the new mixture right over the chalked dullcote and it will cover and take away the chalkyness problem - no need to strip or anything like that!