Monday 12 July 2010

Plain old Water

A while back I got chatting to another miniatures painter at a convention and he mentioned using distilled water to mix paints with. I'd never heard of this practice before so asked him about it. He insisted that using distilled rather than tap water was better for diluting and blending with than any other option. He was a little vague as to why this should be the case so I decided to investigate.

Tap water actually varies in quality from one area to another. London (where I live) for instance has relatively high levels of Calcium Carbonate (from dissolved limestone/chalk) in it. This is why kettles get lime scale inside them and why irons ‘fur up’. If you use water to dilute paint for washes you are also adding a small amount of this mineral to the paint. The water evaporates and leaves behind the paint and the mineral. In really ‘hard’ water areas this could seriously affect acrylic paint and can - it is claimed- result in powdery looking deposits on models. I've never seen this myself but it sounds like a logical result when using water with a high mineral content in it.

Distilled water on the other hand has zero mineral content because it is made from condensed water. The process of making distilled water is simple and can be repeated easily at home. Boil water and let the steam hit a cold surface like a mirror or tile. Some of the steam will condense back into water. What’s happening here is the water molecules become a gas when heated but the mineral molecules in the water do not. So the steam is ‘pure water’. This process is called distilling.

Another suggestion that is hinted at on several painting forums is that acrylic paint can 'react' to the chemicals in drinking water, and by that I assume they mean the added Fluoride. None of the people making this claim explain how this process works. There are a lot of conspiracy theories on the Internet about fluoridation of water but I'm pretty sure that the evil hive over-mind that runs the planet didn't decide to add fluoride to our water to thwart the work of model painters using acrylic paint. Nor do I believe that fluoridation is responsible for corrupting our "bodily fluids".

However on the principle that less is more I have started to use distilled water for blending and mixing etc. Its cheep and can be bought at any service station/garage and is even available in supermarkets. I still use tap water for brush cleaning and drinking... although of course I don't drink the brush water. That would just be weird. 

I'd be interested to hear what you use and why, and of course if you can offer up some scientific reasoning behind some of the claims of 'chemical reactions' when using tap water that would be great.


  1. I use tap water(15.2 dH just above average hard water). So far i have nothing to complain. It didn't give me any problems.

  2. I use boiled water for my paint cleaning pots, not hot water - just water that has been boiled. I also add a tiny drop of either washing up liquid or flow improver.

    When I use Klear (or Future) washes, or GW washes for that matter - I have a bottle of distilled water in the workroom which I use.

    I am never sure of the actual worth, but now it's habit! I would be very surprised if any UK water was 'bad' for painting, It's just that boiled water, filtered water and distilled, must by definition be better - I think.


  3. Our water here in the Mojave Desert is even harder than London water (I'll drink either, in a pinch!). We always have a few gallons of bottled water in the garage: for making ice, for filling the fish tank, and for painting. Having seen what builds up in the shower and in the taps, I just don't want that going on my figures!

    The least expensive distilled water here is from Wal-Mart, but they're stocking less of it; so we've gone to "purified' water, which has been through a reverse osmosis process, and is quite pure.

  4. I'd be amazed if any paint manufacturer used distilled water in the manufacture of thier paints in the first place. Add to that the purity of the raw materials used to make the pigments and the amount of crud on your average painters pallet that the 'tap water' would make exactly jack difference - IMHO.
    Get you Mrs/mates to make up two samples for you blind so you don't know which is tap and which is your bottled distilled/purified/other water. Paint away and then you make the judgement if you can tell the difference. It's your cash.

  5. I'll have you know there is no "crud" on my pallet! (LoL)

    I'm sceptical about the 'benefits' but at £1.50 for a 1 litre bottle I don't consider it a particularly extravagant waste of money. The painter who gave me this 'tip' was quite adamant about the benefits, but as I mentioned in my post he was vague on detail. Having said that he'd been painting for over 30 years and the standard of his work was very high indeed, so I decided he probably knew a few things I didn't.

    Personally I can't see a difference in my results but certainly using Distilled water instead of tap water hasn't done any harm.

    Thanks for all your feedback guys. It's always interesting to look at some of these "old painters tales" to see what other people do.

  6. Having lived and painted in an area that had soft water for 15 years, when I moved to an area that had hard tap water I definitely noticed a difference in the behavior of the paint when I thinned it. After I noticed calcium and iron deposits building up in sinks, i started searching around on the web and found the tip on distilled water and I've been using it with good results ever since.

  7. Even if there is no Hard Evidence for using boiled, distilled or even bottled water. Common sense says that washes in particular would benefit from non-tap water.

    Some years ago I was enrolled in a Water Colour painting course. We would use huge pots of tap water (Worcester area) and I would add flow improver. The teacher had never heard of such a thing! And I was told so in no uncertain terms.

    However by the end of the course, about 50% were using flow improver - my flow improver!


    I've enjoyed the thread and comments, well done to all.


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