Preventing "Frosting" Sealer Spray

[The Joe]

Hello all!

This is something I've been battling with for a long time.  More often than not, even under ideal conditions, the seal coat of spray varnish I apply tends to "frost" and turn to a white/icy look that obscures the paint on the miniature I spray.  

 

This has happened with pretty much every brand of spray varnish I've used and is quite frustrating.  I'd appreciate it if I could get some helpful tips on this...

[R2ED]

If it's happpening on every brand you try, I'm just curious, how long are you letting the paint cure on your mini before you varnish? What paint are you using?  And lastly are you using oil or solvent washes?

[K2h2m3]

Frosting is usually due to moisture in the air. I live in New England and used to look for humidity no higher than forty percent if I was final coating. This is the number one reason I purchased an airbrush.

[SotF]

Let your paint fully cure, I tend to wait a few days between finishing and using a sealer.

 

You also want to be careful with superglue if you have any basing to add after it...

 

And a way that can fix the frosting is, normally, to get some brush on varnish and put a thin layer over it

[ManvsMini]

Frosting can also be caused by going too heavy with the matte sealer. The matte sealer has particles mixed into it that disperse the light, so if you put too much on top of an area that already got sprayed it disperses the already-dispersed light and causes that frosted look. Make sure you aren't putting on really thick coats, and try to avoid coating it multiple times.

 

This video is a way you might try to fix the issue (never tried it myself, and he does specifically mention using a lacquer based sealer, not sure if all sealers will behave this way).

 

Best of luck to you.

[The Joe]

13 hours ago, K2h2m3 said:

Frosting is usually due to moisture in the air. I live in New England and used to look for humidity no higher than forty percent if I was final coating. This is the number one reason I purchased an airbrush.

Ugh.  Yeah that sounds like it might be the issue.  I live in Southwest Florida.  Getting humidity less than forty percent is impossible.  Got any recommendation for a decent, basic airbrush to seal coat with?

[Inarah]

We have high humidity here in the midwest, and I can successfully clear coat and use Dulcote with humidity at 60% or higher during the summer.    You must shake the cans every time for even distribution of the matte agents, though.  If you fail to do that each and every time you can end up with too much of it left in the can. 

 

As already stated, if you go too heavy it can be a problem.  I usually do several light coats.  

[haldir]

1 hour ago, The Joe said:

Ugh.  Yeah that sounds like it might be the issue.  I live in Southwest Florida.  Getting humidity less than forty percent is impossible.  Got any recommendation for a decent, basic airbrush to seal coat with?

 

Harbor Freight has a decent airbrush. If your just gonna use it for clearcoats, then it should work. There are other cheap options as well, ebay has em. Most are Chinese brands, but you can find decent ones. Remember thou, you'll need a air source & something to catch the overspray.

[Fencig]

i recently bought a bottle of Testors dull-coat 1160 for $5., i brush it on.  Results are excellent so far. No more rattle cans for me,  (except for primer on metal)

 

frosting, white dots (pimples)= no thanks

[cmorse]

On 4/4/2022 at 12:37 PM, The Joe said:

Ugh.  Yeah that sounds like it might be the issue.  I live in Southwest Florida.  Getting humidity less than forty percent is impossible.  Got any recommendation for a decent, basic airbrush to seal coat with?

 

If all you plan to do with it is varnish and prime I'd consider a cheap external mix like the Badger 350 or Menards/Home Depot/Ebay equivalent. The brand doesn't really matter. They are cheap, easy to clean, no maintenance, and do the thing. The Badger and hardware store versions also tend to come with US standard fittings that can simplify things if you are planning on using a normal air compressor, like many people have in their garage, though that can also complicate things if you want to use most airbrush specific compressors.

[ferret]

On 4/4/2022 at 7:30 PM, Fencig said:

i recently bought a bottle of Testors dull-coat 1160 for $5., i brush it on.  Results are excellent so far. No more rattle cans for me,  (except for primer on metal)

 

frosting, white dots (pimples)= no thanks

Like you, I use Testors Glosscote and Testors Dullcote brush-on  for sealing.   The brush-ons work well for me.  However, people should use a very light touch when applying them.  The solvents in the lacquers can soften acrylic paint enough that it will smear if it is brushed more than very lightly.  After I messed up details on the first min by "normal" brushing , I have had no such issues if the lacquer is very lightly brushed on. 

 

I don't use an airbrush simply because I am lazy and it is a a bit of a bother to clean an airbrush after spraying lacquer.  Just doesn't seem worth it since I usually seal only a few minis at a time. 

[Fencig]

On 4/6/2022 at 8:53 AM, ferret said:

Like you, I use Testors Glosscote and Testors Dullcote brush-on  for sealing.   The brush-ons work well for me.  However, people should use a very light touch when applying them.  The solvents in the lacquers can soften acrylic paint enough that it will smear if it is brushed more than very lightly.  After I messed up details on the first min by "normal" brushing , I have had no such issues if the lacquer is very lightly brushed on. 

 

I don't use an airbrush simply because I am lazy and it is a a bit of a bother to clean an airbrush after spraying lacquer.  Just doesn't seem worth it since I usually seal only a few minis at a time. 

yikes, thanks for the warning.  I didn't see any sign  of this here, but it's good to be aware of.

 

Here in Colorado we have 3 to 5% humidity, the Testors dried so quickly i don't think it had time to attack the Acrylic paint under it. I almost went for the Dullcoat in a spray can, also cheap and popular, but i read it can also clump and leave white pimples.

[The Joe]

On 4/6/2022 at 10:53 AM, ferret said:

Like you, I use Testors Glosscote and Testors Dullcote brush-on  for sealing.   The brush-ons work well for me.  However, people should use a very light touch when applying them.  The solvents in the lacquers can soften acrylic paint enough that it will smear if it is brushed more than very lightly.  After I messed up details on the first min by "normal" brushing , I have had no such issues if the lacquer is very lightly brushed on. 

 

I don't use an airbrush simply because I am lazy and it is a a bit of a bother to clean an airbrush after spraying lacquer.  Just doesn't seem worth it since I usually seal only a few minis at a time. 

Thanks for the warning @ferret.  What kind of brush do you typically used to apply the sealer coat on your miniatures?  Synthetic or inexpensive natural hair?

[Adrift]

I’ve only ever had one miniature frost after a sealing coat of dullcote was sprayed on it. It was simply that I had sprayed too much. When I seal a figure nowadays I make sure it is 6-12 inches from the can, and each angle gets one, small burst. 

[ferret]

23 hours ago, The Joe said:

Thanks for the warning @ferret.  What kind of brush do you typically used to apply the sealer coat on your miniatures?  Synthetic or inexpensive natural hair?

I use a brush that is a blend of natural and synthetic fibers.  it is a slightly stiffer than the sable watercolor brushes I use for most of my painting.