mixing paints for airbrushing

I'm glad to see that I'm not the only one who never "got" that whole consistency of milk thing. I've even seen people go so far as to say 1%, 2% or whole... Are there really folks out there who can actually judge that by eye? .... I think maybe they're just a wee bit full of it.

I do it the same as Don does. Work with it til it sprays the way I like. Each session is a new and unique adventure....what worked like a champ yesterday may be an abysmal failure today - and vice versa.

I agree that the "consistancy of milk" suggestion is not very helpful.  We cannot judge viscosity very well by eye.  I start with a 1:1 mixture on fresh MM enamel.  Then I try it.  If it is too runny I add paint. If it spits or is rough, I add a bit of thinner.  Sometimes I can use slightly off-mixture batch by pressure adjustment.  This is an experience thing- you eventually get the feel of a proper thinning ratio. Also, it is not super critical and does not need to be done to a percent or two. I'll be my mixtures vary up to about 20% with little difference in spraying behavior.  With enamels I find I have to add more thinner to an old bottle, so I start with a bit more.  My mixing is strictly by eye.  BTW, I use siphon feed so I can store paint in bottles, and once a color is mixed to proper ratio I can use it for entire kit.  Main reason I like siphon- no need to transfer to cup and continually clean out cup.

I should have said, all the paints I use are enamels--no acrylics, except for washes.  I don't have experience and therefore have no advice for acrylics.

Here's the link to the FSM video I mentioned.

www.finescale.com/.../Thinning%20paint.aspx

It probably depends some on the type and brand of paint you're using.  I use Model Master, Humbrol and WEM Colourcoats, and for all of them I now thin them half-and-half, using lacquer thinner.  There is a video posted on the forum from the FSM staff about thinning for airbrushing.  After watching it, I decided I wasn't thinning the paint enough.

What I do is open up a new bottle; drop in a couple of B-B's; reclose and shake.  Then I open the bottle and stir, then dump it into a disposale container (usually a used yogurt container; we have lots of them).

Then I refill the original bottle with lacquer thinner and dump that in with the paint.  Mix it all up and return it to bottles--with the B-B's, that will serve as mixing assistants when you shake up the bottle..  Of course, now I have twice what I started with, so I have to have another bottle to hand for the overage.

Tower Hobbies sells empty, spare mixing bottles in two sizes (equivalent to Model Master size and the other equivalent to Floquil RR colors).

Some folks say that mixing colors thin enough for airbrushing will reduce their shelf life.  Personally, I haven't had this happen.  I've had some bottles ready-thinned for airbrushing for years.

Thinner paint means thinner coats, and more of them for coverage, but I've been having pretty good results with this method.  But they'll run or puddle if you spray too much too fast.

And, as usual, try everything first on some old kit that doesn't matter too you.  Practice, practice, practice.

Good luck.