New DullCoat


UPBigBoy

J&A Paint Shops
Has anyone else had a problem with the new dullcoat? I've tried to thin it with lacquer thinner and tuluol either using each alone and also combining them but what happens is the dullcoat is drying with a white haze to it and in some spots actually turning the finish white. Anyone else having problems with this?
 
I've been using Testors Metalizer thinner for Dullcoat with no problem. Both Metalizer and Dullcoat are laquers and generic laquer thinner from the hardware store doesn't seem to react all that well with them. I thin it 60% paint to 40% Metalizer thinner for my airbrush. I don't measure it precisely, just by eye in my airbrish bottle so the exact ratio doesn't seem critical. As far as the white it is known as blushing and happens to all laquer paints because of high humidity. Laquer absorbs moisture in the air until it cures and that is what causes it to blush. For that reason I try not to use dullcoat or any laquer paints when humidity is over 60% at the most.
 
I've been using Testors Metalizer thinner for Dullcoat with no problem. Both Metalizer and Dullcoat are laquers and generic laquer thinner from the hardware store doesn't seem to react all that well with them. I thin it 60% paint to 40% Metalizer thinner for my airbrush. I don't measure it precisely, just by eye in my airbrish bottle so the exact ratio doesn't seem critical. As far as the white it is known as blushing and happens to all laquer paints because of high humidity. Laquer absorbs moisture in the air until it cures and that is what causes it to blush. For that reason I try not to use dullcoat or any laquer paints when humidity is over 60% at the most.

I shot the dullcoat at 22% humidity according to the humidistat in the paint room; Is there anything that can be done to get the blushing to disappear? As far as thinning, I thinned the dullcoat to about 70% dullcoat and 30% thinner. I'll have to see if one of the out of town hobby shops can ship me Metalizer thinner as our little hobby shop doesn't carry very much in the way of paints
 
did you try testors 1159 directions say "Use to thin only Testors Glosscote and Dullcote Lacquers 50/50 for airbrushing"
 
The only time I had Dullcoat haze on me was when I tried using some 70% Isopropyl alcohol on the finish after I had let it dry. I was lucky though and had not applied decals yet. I was able to spray another thin coat of colour and move on, lesson learned. Is there any chance anything was contaminated with alcohol while spraying?
 
I shot the dullcoat at 22% humidity according to the humidistat in the paint room; Is there anything that can be done to get the blushing to disappear? As far as thinning, I thinned the dullcoat to about 70% dullcoat and 30% thinner. I'll have to see if one of the out of town hobby shops can ship me Metalizer thinner as our little hobby shop doesn't carry very much in the way of paints

With color pigmented laquers like used on a car or a truck blushing can be removed by rubbing the finish with rubbing or polishing compound until it clears out. You won't have the same results on a train model because of the uneven surfaces created by grilles, vents, door edges, and all the other nooks and crannys. What does clear up, if it clears up will also now have a dull shine to it from polishing. It will be worse looking than before you touched it.

The humidity level you noted is well below any moisture problem. That leaves 2 other possible reasons. Either a reaction to whatever thinner you used or it wasn't thinned enough. The flattening ingredient in Dullcoat is talc which is processed fine enough so to become transparent when applied but the denser the mix the more concentrated the talc and the whiter it will look when dry. The wrong thinner may dissolve the liquid of the dullcoat but not dissolve the the solids. Not a very technical explanation but I hope you see the point.

If it will make you feel better I had an engine turn almost ghost white a couple of summers ago. A 3 color paint job, custom decals, the works! No salvaging except to strip it and start all over from scratch. All due to humidity. Murphy's Law struck again. :(
 
I shot the dullcoat at 22% humidity according to the humidistat in the paint room; Is there anything that can be done to get the blushing to disappear? As far as thinning, I thinned the dullcoat to about 70% dullcoat and 30% thinner. I'll have to see if one of the out of town hobby shops can ship me Metalizer thinner as our little hobby shop doesn't carry very much in the way of paints

I think that your main problem was the dullcoat wasn't thinned enough. I have always thinned my paints 60%, meaning 60% thinner. I also shoot at slightly lower pressures, this allows a coat of paint to go on much smoother. I can also apply a much thinner coat of paint as well. Must work, as I've painted professionally for over 30 yrs, and have had only one complaint, and that we tracked down to a brass alloy that had a high acid content in the alloy itself. A repaint with Automobile Lacquer fixed that.

As to the blushing problem, I've found that if you spray a coat of glosscoat over the dullcoat, the blushing goes away. Since it was Testor's Dull coat, you must respray with Testor's Gloss coat. Then you can apply another coat of dull over that.
 
I think that your main problem was the dullcoat wasn't thinned enough. I have always thinned my paints 60%, meaning 60% thinner. I also shoot at slightly lower pressures, this allows a coat of paint to go on much smoother. I can also apply a much thinner coat of paint as well. Must work, as I've painted professionally for over 30 yrs, and have had only one complaint, and that we tracked down to a brass alloy that had a high acid content in the alloy itself. A repaint with Automobile Lacquer fixed that.

As to the blushing problem, I've found that if you spray a coat of glosscoat over the dullcoat, the blushing goes away. Since it was Testor's Dull coat, you must respray with Testor's Gloss coat. Then you can apply another coat of dull over that.

A couple of questions -

1. What are you using to thin the dullcoat?

2. What make/model of airbrush are you using

3. Do you know what has changed in the NEW dullcoat as I never had this problem before.

Thanks in advance

Jim
 
............"A couple of questions -

1. What are you using to thin the dullcoat?

2. What make/model of airbrush are you using

3. Do you know what has changed in the NEW dullcoat as I never had this problem before.........."

I use TRU-COLOR dull coat,it's acetone base to thin it I use non scented finger nail polise remover (actone)

Use a Paasch VL (the newer model) and I shoot at 40 p.s.i.

It's been so long since I've used anything I would have no clue?

L
 
A couple of questions -

1. What are you using to thin the dullcoat?

2. What make/model of airbrush are you using

3. Do you know what has changed in the NEW dullcoat as I never had this problem before.

Thanks in advance

Jim

1. I use really just plain Xylol. I only use lacquer thinner ocassionally for stripping small brass locos that are too small for the media blaster.

2. Depends on the colors and model size I'm spraying. Vast majority is with a Passche`H with a H1 tip. On others I may use the HF model, a gravity fed AirPro, or a Badger XF100.

3. No, I don't know what has changed. I'm on my 3rd bottle of the "new" formula, and haven't had a problem at all.

The only blushing that I've had with dullcoat was on my tender tops, where some judicious use of alcohol allowed me to simulate the water treatment chemicals used in the water. When these dried on the tenders, the chemicals generally dried out almost white.
 
Last edited by a moderator:



Back
Top