I have run into a problem today that has me really scratching my head.

Previously, I made my washes of 90% alcohol and 10% paint with fair results. After reading several articles on the subject, I decided to try a wash of 90% thinner and 10% paint. I ended up with terrible results.

I am working on the AFV Club M-10 Wolverine. I painted the upper hull with Model Master OD Green (rattle can). After it dried overnight, I coated it with Model Master Gloss Coat (again, ratle can). After drying overnight, I applied the thinner-based wash and say it attack the paint. It also happened when I applied this wash to the interior that had been painted with MM Flat White (rattle can). When using this wash with parts painted by hand, the results were good.

Is this a screw up on my part or is it a problem with the spray paints? What am I doing wrong? I haven't invested in an air brush yet, but it might be time. Does anyone think this is where the problem is (air brush vs. rattle can)?

Thanks in advance for any insight on this.

The aerosol cans of Model Master are solvent based. The wash you used is also solvent based. The wash caused the clear coat to become slightly soluble and probably caused wrinkling. Depending on how long the base coat and clear coat cured the thinner in the wash could have soften both coats. The best clear coat before applying wash is Future Clear Acrylic. The next best would be Model Master Aryl Clear. You could have also used an acrylic wash. The reason the alcohol thinner wash did not cause any problems is the alcohol is a relatively weak solvent. Even it used in sufficient quantity can cause lifting.

Sounds like the thinner you used doesn't like the lacquer paint in the MM cans. I've had the same thing happen to me with mineral spirits and MM spray cans.

You might want to try to put a coat of Future down over your spray coat. Brushing it works fine with a wide soft brush. Just give it some time to cure and you should be good to go.

Hope that helps!

- Frank

I'm going to say what Don and Frank said. Because you used enamels
from a rattle can mostly, the kind of thinner you used in your wash attacked
the rattle can layer underneath. If you intend to continue in this way of painting,
you'll need to put a barrier layer down.

Future floor wax, once it's good and hard, will not allow the enamel type
of solvents and thinners used in a wash to attack the paint underneath.
Another way is to use acrylic paints to make your washes and then the
barrier layer isn't necessary. . . since acrylic paints are basically plastic
suspended in water. . . and will not attack enamel paints from a rattle can
or from a jar of enamel.

Now Barry, I don't want to hurt your feelings, here. But anytime a modeler
is doing something for the first time or trying a technique she/he isn't sure
of just what the results are going to be, she/he should do that step on
a practice piece of plastic. I can't tell you how many times in the past two
years here on the Big A that I've read threads like yours. The modeler started
a step they hadn't done before and just crossed their fingers, I guess.
By doing a new technique or procedure on a practice piece of plastic,
you won't ruin a model that has a lot of work in it or costs a lot of money.
This kind of thinking is part of the discipline required to grow as a modeler,
in my view. I feel a modeler does not want to get too eager to finish a
model too quickly. No modeler wants to be "surprised" with an unhappy result.
I hope you are not offended by what I say here. It is not my intention to say anything
other than hoping you'll give more thought before you try something
new; and practice on a piece of scratch and learn the important
lessons that way. Thus when you turn your attention back to your
model, you'll know exactly what is going to happen. Planning ahead and
a lot of patience is important to grow as a modeler, I feel.
Good luck to you.

maybe this might help:

the 3 main types of paint used by most modellers are lacquer(Gunze Mr Color), acrylic(Tamiya, Gunze Mr Hobby, etc) and enamel (Model Master, Humbrol etc). Lacquer thinners will dissolve all 3 types of paint. Acrylic thinner will dissolve acrylic and enamel. Enamel thinners will only dissolve enamel paint. given this situation, it is possible to apply a lacquer base coat, spray on an acrylic second colour, and use enamel paints to do a wash without much worry (except your wallet from buying all those paints and thinners) If you start with an enamel paint as your base coat, then attempting an acrylic wash is not likely to work without wrinkling and other problems.

alcohol: given the right concentration will dissolve anything, so experiment!

good luck with your modelling

One of the key players in this scene is the nature of enamels.Very durable when fully hardened.This takes 3 days or so.After that,you won't have any problem with washes of solvents.General rule is,if you can't 'dent' the paint with your thumbnail,it's cured.
cheers!

After reading Lim Tee reply I felt I should perhaps make myself more clear
Lim wrote:

If you start with an enamel paint as your base coat, then attempting
an acrylic wash is not likely to work without wrinkling and other problems.

Now back to my point below, I want to make as clear as possible:

When I'm talking about using an acrylic wash, I'm meaning that this wash
will be applied with a brush by hand, not using an airbrush. For me and
a lot of other modelers I know, we make the acrylic wash by mixing the
acrylic paint with water. . . Not some solvent. Never have I has an acrylic
wash as I've described here attack any kind of paint underneath. . . once
that base coat (of any kind of paint) was set up good and hard as the
Sultan indicated.

So I believe we're having a minor communication problem here.
Of course, we all know that effective communication is very hard to
achieve. . . . Any married person can tell us that

Thanks to all of you for the help. This is starting to make more sense now.

Please do not worry about me taking offense at any comments here. I know from my short time as a member of the group that everyone seems to have only the best intentions and are only passing along the results of their experience.

Let me guess...you applied yout wash all over the model withthe expectation of wiping off thexcess, the so called sludge wash promatoed by a major magazine. This is a great way to ruin a finish and the decals you so carefully applied.
When applying a wash, use a very fine brush dipped in your mixture. Place it a the junction of panel lines, at the base of rivets and in other creevasses. Capillary action will draw this along with little or no excess paint on the finished surfaces, but a nice shadow effect where you want it. A bit of drybrushing will blend this down.
I've done this for years with no problems, but with a gloss coat and directly on flat paint, both oil and enamel over enamel thinned with "paint Thinner" from the hardware store.

Hi there The best results ive had with washes has been with artist tube oils and a turpentine substitute called TURPENOID. its very mild and will definatly will NOT damage your base coat regardless of type of paint used. it can be purchased at any art supply or hobby lobby etc.