Airbrush Paint Thinning Newbie Question

it depends on which paint you are using, and which thinner for that paint

For most paints and thinner combinations, you don't want to do that at all. You also don't want to pour thinned paint back in with your fresh paint.

For some acrylics, you can thin them with the company thinner and pour them back in or store them just fine.  I know, 47 people will now say "Never do that!!" , but, they don't use those brands, or they would know that the tip to getting them to last a long time is to replenish the amount you took out of the bottle with the "house brand thinner" or distilled water after each usage. (so, "don't pour water thinned paint back" but, it is suggested to "add water to your paint for long life", lol)

So, for Model Master, Polly Scale and Aeromaster,,,,it would be okay, MisterKit and LifeColor also,,,,,,but, not any acrylic that you thinned for airbrushing with Lacquer Thinner. I also think that the Vallejo group of paints doesn't like it, but, I am not sure, I don't use very much of those.

Back in the day the "don't pour thinned paint back in" became the Meme, partly because we could thin Testors and Pactra PLAs with Ronson lighter fluid, and it turned into goop practically overnight in the jar.

I have 3 year old bottles of Aeromaster that have been thinned and shaken from the beginning,,,,,,and they are still liquid in the bottle. (3 years old at my house,,,,,plus they had to be 10+ years old when I bought them) And they don't have any flakes of dried paint in them, either. (the other acrylic Meme)

I would say get a spare bottle and experiment a bit,,,,,,,,,and then you will know for sure, with the exact liquids you are actually using.

Rex

Great Information.  I wouldn't pour it back in the bottle, but put it into another bottle for keeping for the next time I would need to use it instead of thinning it each time.

I'll experiment and see what's best.  Thanks for the information!

I store my custom mixes of Tamiya paints thinned with Tamiya acrylic thinner in LDPE bottles.  I have never had an issue.  Even 6 months later, they sprayed beautifully  Interestingly, thinned Vallejo paints didn't last long.  I don't know if I did something wrong or if Vallejo cannot be stored like that.

Ditto what Rex and Chris say. I use mostly Craft acrylics and often have to mix to get the color/shade I want. I just store the thinned mixture in LDPE bottles and 'shake'n'spray' when I need that color again. Have some that I know are close to 2 years and still spray fine.

I use a Badger siphon feed brush, and always mix up paints I will need in jars.  They will eventually go bad, but not during the time it ordinarily takes me to build a model. There are several sources for such jars in addition to airbrush mfgs.  Many hobby shops carry jars and boxes of jars.  Even if you have a gravity feed airbrush, you can pick up a few jars and pre-mix the paint. I think this is particularly good if you are mixing color, since I am afraid I will not get exactly the same color any two times I mix it.  But it is handy to have the same thinning ratio even with an out-of-the-jar color, when I am airbrushing a model.

Thanks for all the input guys!  I will do the pre-mixing and experiment.  So I'm still new what is LDPE jars?

Thanks

Low Density PolyEthylene,,,,,,,,in other words, the soft plastic bottles, like the Vallejo paints come in

you can buy some here www.wholesalesuppliesplus.com/StoreCategory.aspx Unless Chrisk-K has a better/cheaper source.

They are just about the same material as the Ketchup Squirt bottles,,,,,which you can also buy and use for dispensing Acrylic Thinners.

Rex

Lots of cheap LDPE bottles from Chinese sellers on eBay.  I bought thirty 10 ml LDPE bottles for $10 including shipping from one of those sellers.  It took about 3 weeks to receive them.  

that is a better deal

I only used the source I linked to because I would throw some LDPE bottles and caps into the cart when I bought my PollyScale jar caps from them,,,I was always over the free shipping minimum anyway

LDPE bottles sold by Chinese sellers on eBay are of excellent quality.  The caps are truly air-tight: I tested with both IPA & lacquer thinner to detect a possible leak.  I don't think I'll ever buy another LDPE bottle.  30 will last forever :-)

They are good prices Chris. I like and use bottles with a dropper tip - I can put in a few drops or squeeze almost a cupful into my Gravity feed AB. I bought mine from SKS Lab Supplies (I think) but they were more expensive and the same as these:

http://www.ebay.com/itm/50Pcs-15ml-Empty-Plastic-Squeezable-Dropper-Bottles-Eye-Liquid-Dropper-LDPE-/181476496273?pt=LH_DefaultDomain_0&hash=item2a40d79391