Right fellow modellers, I am having some real issues with Matt varnish. To date I have been predominantly a humbrol matt varnish spray user and have had consistently good results…I say ‘had’!!! Recently the last few models I have made I have ended up with frosting on the model in some very awkward places and although the Olive Oil technique works to get rid of it, it is bloody annoying. I have then tried to use Vallejo Matt Varnish and used it with an airbrush and painted on. However no matter what I do it comes out Satin at best. I have a dehumidifier in the room to eliminate that factor and the room temperature is consistent.
Can anyone suggest alternate products or solutions with the Vallejo varnish? I think I am going to retire the Humbrol spray varnish. All I will say is I live in the UK so ideally would like suggestions that are easily obtained over here
Testors Dullcoat is my go-to dulling spray. While I usually use enamels I do occasionally use acrylics and have had no problems with compatibility. I have not used it with Vallejo.
Any time I am trying a new paint or post painting product I make a test on scrap. Paint a piece of scrap plastic with the paint- when thoroughly dry try the clearcoat.
Other matt finishes include general purpose flat clear acrylic spray and matt clear polyurethane, in addition to all the hobby shop stuff.
I’ve always had great results with Humbrol Matt Clear from the little tin. If I have a hint of “frosting”, it’s usually due to my thinner to paint ratio. But you will not find a better, more flat top coat than Humbrol. I have experienced Testors taking on an amber tone over years, and interaction with decal solvent & setting solutions. Neither is immediately apparent, but with time they appear and become more visible.
Yes, Testors clear coats could yellow over the years, for the older stuff. They seemed to have fixed that several years ago. Sometimes frosting is paint blush. Blush is caused by rapid evaporation of thinner on very humid days. Lacquers are particularly susceptible to it because of their quick dry. I suppose acrylic lacquers could blush too.
Blushing happens because the rapid evaporation cools the paint surface down below dew point, and water (dew) condenses on the surface giving a rough surface. For clear coats the rough surface makes them look whitish and matt. Never paint with a laquer solvent paint when the dewpoint is close to the actual temperature.
This is why I love this site. I would usually browse and pick up nuggets like this and move on , but I use acrylics and never have had a problem with testors my self. I do have a bottle of Microscale’s Micro Flat but no excuse to test so far. Hope your problem gets settled. P.S. Guy Fawkes; the only man to enter parliament with honest intentions. Happy Boxing Day