Thinning Humbrol for airbrush?

[Madman Lighting]

Hey,
I'm using some Humbrol enamel for airbrushing and I'm wondering if I'm doing it right. First, the stuff comes out of the tin pretty thick, so I'm wondering if its gone bad. I use the Humbrol brand thinner but I can't find a specified thinning ratio, so I go with about 1 part paint to 1.5 parts thinner. Then I shake it in my power shaker to make sure its mixed.

It sprays OK at first, a little bit thick, but halfway through it seems to get a lot thinner and suddenly I'm misting paint all over when before I was putting down a thin line.

I'm using a Paashe double action, medium needle, with regulated air at about 20 psi.

I never had this problem with Model Master, always worked great but that's not an option anymore. Any thoughts?

Thx.
-John C.

[jpolacchi]

I'd say thin the paint until it "looks right". Just thin it and continue to thin it until it has the correct "consistency". Maybe check out some Youtube videos? If its "old" don't forget to run your thinned paint through a strainer. If it seems dodgey, I'd spray some on some styrene stock first(practice shots) to see how it goes on and how/if it has any drying or curing issues? I wonder if need be...if you can thin Humbrol out with lacquer thinner? I'm not sure if that's any better than using the brand thinner or mineral spirits? I certainly don't know everything, so hopefully some others will chime in with their ideas and advice.

[dizzyfugu]

Humbrol enamels had a shaggy quality level during the last years, since production went to China (when the RLM tones were introduced) and later also to Belgium. Some of these paints have horrible properties, including poor opacity and "glossiness", unwillingness to dry properly (some extra heat helps, though), yellowing (esp. 22), a gooey consistency and pigment/thinner separation (147 is prone to this). Sometimes you get multiple symptoms, every tin a surprise!

However, I think that your basic problem is that most Humbrol enamels have rather "solid" pigments and that they are not suited well for use with an airbrush. Even thinning (nitrous thinner works on them well, as well as acetone and nail varnish remover) them won't probably help much, as I think that - beyond dubious quality - the issue is a mechanical one. But that's just my 2 cents.

[Bellerophon]

That may be the problem, that it's a fool's errand. I always loved Humbrol for brush painting - my favorite experience with it was brushing gloss dark sea blue onto a Corsair, and all the brush marks magically leveled out. I don't recall if I ever tried to airbrush it. But settling in the tin, the pigment gets as thick and heavy as clay, making it a lot of work to stir, so I'd expect it to clog an airbrush. That the thinned Humbrol comes out thinner as you go along suggests to me that it is separating in the color cup while you're spraying it.

[Madman Lighting]

Yea I was kindof afraid of that. Humbrol may just not be intended to be thinned so much for airbrush and I think you're right that its settling in the paint cup, even though I shook it like crazy. Lots of other paints to try.

[Madman Lighting]

Yea... the paint in the tin looks like glop... very thick even after several minutes with my power paint shaker. And if its not made right and settles in the cup after just a few minutes... then why am I bothering. I'm really sad to see Model Master go, never had any trouble with that brand.

If Humbrol is made in China now then I'm not gonna bother, I'd rather try some other paint then waste my time with junk.

Thanks for the help guys.
-John

[jpolacchi]

Look into ARCHIVE X.They are all resurrected Floquil R.R colors.Its an enamel,and I think also "very thick" in the bottle, but it is an amazing paint as I have heard from others.Airbrushes beautifully. Thin with mineral spirits.

[seam-filler]

If Humbrol is made in China now then I'm not gonna bother, I'd rather try some other paint then waste my time with junk.

Humbrol enamel paint is made in London or the North-East of England (there are 2 production sites - I believe one makes it, the other packs it). The acrylic paints are made in Manchester, England.

I've seen quite a few posts in other forums decrying the quality of the enamel paints in the last couple of years. I gave up on enamels when I got 2 pots of the same colour that were completely different shades - worse still, they were nominally from the same batch.

[jpolacchi]

That's why I turned to EVIL BAY. You pay anywhere between two and three times the original retail price, some sellers were wanting ten times more, but you just pass them by. One guy was trying to get $50.00 for a 1/2 oz. of a M.M color. Most I'd shell out for a "rare/hard to find color was $10.00-$15.00 so long as it didn't say "Rustoleum" on the label. As I understand it that's when the Testors paint(including the Floquil line) and M.M line just turned to complete . I bought NOS Floquil enamels also from the mid/late 80's&early to mid/late 90's and some in the early 2000's. Up until Floquil was changed sometime after 2005 or so? Its hard to get a good deal on EVIL BAY, but I got a few, most of which turned into "large quantity purchases" so I also got allot of the same colors, but I got some really good military shades and I got taken a few times, but I also ended up finding other people who would sell at a much fairer price and I turned to EVIL BAY for the really hard to find colors which did not come often and you know how auctions can go. I also tried buying paints from sellers in the UK but most wouldn't risk shipping. It was for kind of a stupid reason. Granted the enamels are "flammable" if you hold a lighter to them, but the 1/2 bottles don't explode into flames like grenades. I found a good seller in Australia instead and I bought quite a bit of the old M.M. enamels. None of the paint I bought that was shipped via air from OZ caught fire or exploded,so that shipping restriction out of the UK is B.S.

[Madman Lighting]

I actually found "True North Enamels" out of Maine on the web. I have yet to actually try them, but its enamel, and they had the light sea gray I wanted.

I have to finish stripping the *)(^&*^ Humbol off my Starfury first though and it takes *forever*. I'm using Simple Green to slowly soften the paint, then gently scrap and scrub it off.

Thanks.
-John C.

[Tommy8008]

Soak it in dettol antiseptic liquid. Soaked the saucer from the Enterprise E model in it over night, next day the paint just peeled off. It was humbrol enamel paint.

[SpaceRanger1]

Humbrol enamels must be well-stirred prior to use. I use a Badger battery powered stirrer. If the paint has been stored for a long time and the pigment has settled, I use a small screwdriver to chop up the settled pigment before applying the stirrer. I then re cap the tin and put it on a paint shaker for a few seconds, although Humbrol does not recommend this.

I thin Humbrol with a 50-50 mix of mineral spirits and lacquer thinner for spraying and spray at 12-15 psi.

I’ve used Humbrol enamels for 60 years according to these procedures, and it’s never let me down.