Decanting Paints

Easyrider5258

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I'm wondering whether its OK to pour a quantity of paint in to a 50ml squeezable and sealable screw top plastic bottle and mix your thinner into it and use to fill your airbrush, unused paint in the airbrush can be returned to bottle and stored in it next needed? (Primer in this case) but Aluminium / Silver and other colours as well (have 10 of these bottles to store ready mixed colours). Does anybody do this?
 
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Mark1

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I dont premix paint but if i have some left in the AB when i finished painting i will pour it back in the jar although its been thinned.
 
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Tim Marlow

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I’m sure it’s OK. I only really spray Tamiya, so tend to just dilute the whole jar ready to spray. I actually write RTS (ready to spray) on the cap with a sharpie. Any unused paint just goes back in the bottle.
 
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Easyrider5258

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Thanks for the replies so far, very helpful, I'm thinking that sometimes there is a different thinner ratio to some jobs and if used leftover thinned paint is returned to original container you lose control of knowing the thinned ratio if you see what I mean? and I have large quantities of Primer (200ML) and only need to mix up a small portion. also wondering how long the decanted mix would "Keep" ?
 
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Flip

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Like Tim, I pre-mix Tamiya and Mr Hobby Lacquers in the jar and put either a "T" on the lid to show it's been thinned or "TR" if it's thinned with retarder-type thinners. I tend to do that with a little of the paint mix, which also instantly shows up which jars have been opened and exactly what the colour looks like in reality. As soon as I've taken paint out of the jar, the cap goes straight back on to minimise oxidation. Generally, I tend to use the paint fairly quickly so I've not encountered it going off - had some around for a few months and it's still OK. The experts on this site will be able to let you know how long you can get away with.

Did try a pre-mix with Humbrol enamels once but they didn't even last a week.

Personally, I would be a bit nervous of using any squeezy bottles for paint - once the squeeze is finished and pressure on the bottle is released, air will be sucked back into the bottle through your paint mix. I would have thought that action would accelerate the paint going off.

I definitely wouldn't put thinned paint back into the original paint. Only thin as much paint as you're going to need. Otherwise, use a good quality paint and go for the approach above.
Then, as Tim says "Any unused paint just goes back in the bottle." (of thinned paint, that is) :thumb2:
 

Scratchbuilder

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I mix up paints that I know I am going to use more of in the future. It used to be acrylics, but as I am now going back to lacquers I have a supply of Tamiya type jars to keep it in. One point I will make is to make sure the top is free of paint as when this dries out it will be a big problem trying to get the top off, I have even on a couple of occasions had to revert to plumbers stilsons to grip both the jar/bottle and cap...
 

langy71

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I mix up paints that I know I am going to use more of in the future. It used to be acrylics, but as I am now going back to lacquers I have a supply of Tamiya type jars to keep it in. One point I will make is to make sure the top is free of paint as when this dries out it will be a big problem trying to get the top off, I have even on a couple of occasions had to revert to plumbers stilsons to grip both the jar/bottle and cap...
been there, done that.. more often than I care to mention..
 

Dave Ward

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stillp

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I've found that some of those squeezy dropper bottles can be porous - I've had paint dry up in them.

For glass jars of Tamiya or Mr Hobby, I have a cheap mole-type wrench with curved jaws, which can be adjusted to grip the cap securely without risking cracking the bottle. Most come off with that wrench and a vinyl glove to grip the jar, but if that fails I have a plastic strap contraption sold for opening kitchen jars. (Don't tell SWMBO!)
Pete
 

Tim Marlow

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I've found that some of those squeezy dropper bottles can be porous - I've had paint dry up in them.

For glass jars of Tamiya or Mr Hobby, I have a cheap mole-type wrench with curved jaws, which can be adjusted to grip the cap securely without risking cracking the bottle. Most come off with that wrench and a vinyl glove to grip the jar, but if that fails I have a plastic strap contraption sold for opening kitchen jars. (Don't tell SWMBO!)
Pete
Polythene is slightly porous to gas Pete, that’s why the paint dried up. Mind you, I’ve had Mr Color glass jars dry up on me as well, so that’s just a lose cap at manufacture I think ;)
 

JR

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I'm guilty of putting paint back into the bottle if I'm left with some in the shot glass, thinned normally.
Must try to put the surplus mix in to a glass jar and mark up. Just lassyness on my part .
 
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