I will start this review by stating quite clearly that the recipe's I will list below are NOT mine. They are a revision or tweak of several recipe's that are freely available on the internet as articles (like this one) and YouTube tutorial videos. I can't credit an individual for the original recipe as this is essentially my own variation that I have created that best suits the paint that I use and the results that it produces for me.
This is something that I have not seen covered in many articles. The main reason I suppose is cost. For the equivalent amount of thinner or cleaner purchased from an acrylic paint manufacturer (amazon used as a price comparison) I would run a bill of easily three figures as opposed to the original £50 investment (approximately) that I made to start making my own. The other bonus is that you are able to tweak the recipe with each new batch to cater to your own individual needs/preferences/paint used.
What you will need
The acrylic paint that I use almost exclusively is from the Vallejo range so this exact recipe has been catered for this specific paint range. I will point out however that all of the other recipe lists contain the same ingredients in varying amounts.
Thinner per litre
300ml of IPA 99%
55ml of acrylic flow improver (I use Vallejo but any acrylic flow improver will work)
55ml of acrylic retarder (I use galleria but any acrylic retarder will work)
I will point out that the cost of flow improver and retarder is relatively high (compared to the other ingredients) but I also use these products in their own right as part of my model painting anyway.
360ml of distilled water
360ml of ammonia free window cleaner
240ml of IPA 99%
20 drops of pure glycerine
You may be wondering why glycerine is an ingredient for the cleaner. Essentially when this is run through an airbrush it will leave a very thin coat inside it. This is a natural lubricant and won't affect the acrylic paint that follows it. Its also really good to use when you break your airbrush down for a major clean. I lightly coat all of the moving parts of the brush with the glycerine (and then wipe off) before I re-assemble it. Again this leaves a really lightweight lubricating layer on all of the components that leaves no adverse affect on the brush.
I have worked out very roughly I might add that I can make approximately six and a half litres of thinner and cleaner (or 3.25 litres of each) after purchasing 5 litres of distilled water and 1 litre of IPA. The window cleaner cost me £2, distilled water £6 and IPA £7. While everything else has higher costs they will last a lot longer than the original 6.5 litre batch of cleaner/thinner that you make. As an example the bottle of pure glycerine I bought cost me £5 but I estimate I will need to replace this at my current usage in around 3 - 4 years time! I have used both of these recipes for around 8 months now and they are both fantastic and have not produced any adverse results at any point. The cost savings are significant and the only downside that I have experienced is finding somewhere to store the additional bottles of the ingredients and the high volumes of cleaner and thinner that I make (by storing I actually mean hiding them from my wife!)
Until next time happy model making!