I’ve been using Scalecoat paint for years and have never ever had a problem. However, yesterday I was using flat glaze to flatten the shinny plastic on some recently purchased freight cars (which I have done literally hundreds of times) and this time the finish dried with a milky or white haze to it. I mixed the paint correctly.Then I tried less thinner and more paint, I tried more thinner and less paint, I adjusted the airbrush settings and still the same thing happened. I thought maybe I was using the wrong flat glaze Scalecoat 1 instead of Scalecoat 2, but their website only lists one kind of flat glaze. I don’t believe the paint was particularly old and it was throughly mixed before using. As I said earlier I’m quite experienced using an airbrush so I wasn’t doing anything different than I usually do. I know we have some very fine painters out there and I was wondering if anybody had any ideas why this happened or suggestions to prevent it. Any ideas would be helpful.
I can’t say for certain as I’m not there….but you’ve basically described what we in the automotive paint refinishing business call “Blush”. This occurs when there is excessive moisture in the air. The moisture can be present in the air surrounding the subject being painted or it can be in the air stream eminating from the compressor. Blush often occurs during cold weather conditions or very hot and humid conditions. Almost always it affects lacquer based paint products (although under the right conditions it can occur in enamel based products as well - been there done that).
If Blush did occur, you can wet sand with a fine grit 3M 600-800 grit Wet/Dry sandpaper and reshoot the items. Make certain that the air from your compressor as well as the surrounding environment is dry. I’m assuming that your compressor is equipped with a moisture trap. Make sure it’s still working as over time, with use, trap filters have to be replaced.
Sidebar: I use Scale Coat quite a bit. For flattening a finish it’s safe to use a flat clear on top of Scale Coat. Badger Modelflex, Pollyscale, and Testors Acryl flats work well with no adverse effects. [;)]
Thank you for the information. I work in a lab that actually does testing work with paint. It is equipped with compressors, hoods, and drying ovens ( how convenient that it also works for painting trains)! Yesterday being Sunday and me working an off shift I took advantage of some slow time to do a little painting. I used the “house air” line to power my airbrush and I’ll bet there was moisture in that line. That makes sense. When I paint in my garage (it’s too cold right now) I never have that problem.
Please post back and let us know if the wet-sanding and reshooting suggestion worked.
One reason I suggested using an acrylic in your case is that, ironically, they don’t “blush” as easily as lacquers. So ironic, considering that acrylics are water based! [:P]
Here is what I wound up doing. Whenever I weather a car (an I’m nowhere near the artist some of you guys are) I dullcoat it first then use some rust, grimy black, or some type of “dirt” color to just give it that used look. Pretty much what most guys do. So I was able to cover over the “blush”. I had to weather them a bit more than I had intended, and they came out looking OK. What was somewhat frustrating/scary was the fact that I had been accumulating Kadee, Intermountain and Exact Rail cars over the past few months and these weren’t exactly the kind of cars I wanted this to happen to. Interestingly, I used Floquil oil based paint to do the weathering and didn’t experience the “blush” effect. Perhaps because they were dark colors and only a light misting was used. Again thank you for the help and I will be more aware of the moisture problem in the future.
Very glad you that things turned out well. If you get the opportunity, post some photos of your jobs. We can never get enough weathering photographs on this forum! [8D]