Model Master-consistency question

I'm not a chemist, and certainly no expert on paint formulations, but I have noticed the problem of MM paints turning gooey.  I noticed certain colors are particularly succeptible to this, like black, insignia red, and chrome yellow.  I have bought bottles of black, both flat and gloss, that were already going gooey.  The red and yellow have a telltale sign of turning whitish in the bottle.  When MM paints go gooey or turn whitish, I have not found anything that will reconstitute the paint so that it sprays or brushes well.  I have a pet theory that contamination with thinner (regular paint thinner, MM airbrush thinner, lacquer thinner) accelerates the process, so I am very careful not to get any kind of thinner into the bottles of paint.  This problem might be due to the paint formula changing in response to Federal VOC regulations getting more stringent over the years.  I remember in the 1970s that any enamel could simply be cut with thinner when it started to get dry (due to me keeping the bottle open for too long, or not closing the cap well), and that the gooey problem did not exist.  I have also noticed that the current MM enamels don't cover well, even flat black.  With the old stuff, one or two passes with the airbrush would provide complete coverage, but nowadays I usually need four to six coats to get the same results (for black mind you, not a weak color like red or yellow).

The only thing I have found that works is to get another bottle of paint, or switch brands.  I have started to use Tamiya acrylics cut with lacquer thinner for airbrushing, and it works very well.  But the color selection cannot compare to MM.  Sorry that I can't offer a better solution than tossing the bad paint.

Definitely, Testor's Model Master thinner / paint brush cleaner is the best thing to use (The stuff in the red can, or smaller bottles with red label.  Testor's air brush thinner, the stuff in the black can, will work fine as well.

Since these paints are enamels, they are not compatible with lacquer thinner.  I mistakenly tried to clean up a brush with lacquer thinner recently, and it just coagulated the paint, rather than dissolving it.

I might have to buy some MM thinner...pay that premium see if it helps..all my paints are stored the same way...and my work room is one of my bedrooms I have as an office so its got A/C..

C

I have noticed that buying MM thinner to keep on hand to thin the MM paints when they start to thicken works well.  Hardware store thinner never seemed to mix and thin the hobby paints very well.  I read somewhere (probably here) that thinning paint with solvent from the same manufacturer is the best way to insure a good, smooth mix.   But to your original question.  Are you storing your paint in a consistent, climate controlled environment?   Rick

I've got some bottles of MM that I just opened after 10+ years of sitting, still sealed up like new & they're fine, so far. I have had some Humbrol enamels going bad on me recently though, someone mentioned to me that they had re-formulated (awww come Humbrol on - I like lead in my paint!). Has MM had to re-formulate anything recently?

I would just put a few drops in a bottle cap or artists palette and close the main bottle.

That gives the carrier far less time to evaporate.

just while using them....a few minutes or so..

How long are you leaving them open?

not that old...I mean I got 25 year old bottles of tamiya paints that still work well...and I dont have the problem with them...I just bought a mr Hobby that was thick too...I had to get a bottle ot Mr Hobby thinner..that helped a bit.....now I have a ceiling fan over my desk....could that be drying them out once I open to use them?? I also get the dreaded "pulling" of the paint almost like there is an oily residue on the surface....and I wash the sprues before I start...

GRL

How old is the paint? Perhaps some of the solvent evaporated. Floquil RR colors used to be famous for this.

 I had this problem with gunze paints once and found that laquer thinner helped. I use Tamiya acrylic and MM enamels almost exclusively and for the Tamiya use X-20 thinner or 3 parts 90% alcohol to 1 part distilled water. For the MM stuff i simply use paint thinner. Not brush cleaner though as i found out the hard way it eats right thru some pain brush handles! Not sure what your problem stems from unless it's in you storage method, i.e., too hot/ cold or just a bad batch or something.