Is water the only thing that is appropriate. When using the Iwata with the fine tip its difficult getting an even flow. Just curious.

What size tip Frank? I use water with a drop of windex. A would like to try a medium for thinning and keeper the paint wetter longer for different effects.

4011 reducer

Liquitex is what I have always used.

http://www.#^&#^&#^&#^&blick.com/products/liquitex-airbrush-medium/?clickTracking=true&wmcp=pla&wmcid=items&wmckw=00610-1005&gclid=CPeF1KOQv8wCFRJZhgodVDQE0w

while were on the subject

so ..... what's the best choice for painting aluminum?

thanks guys
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I use pledge floor care. Works great

I use pledge floor care. Works great

Very interesting.....

I've been using Golden Airbrush medium for a while and
really like it.

http://www.#^&#^&#^&#^&blick.com/products/golden-airbrush-mediums/?clickTracking=true&wmcp=pla&wmcid=items&wmckw=25321-1008&gclid=CND2iYegxMwCFdNahgods9QP9Q

Createx also makes a retarder which can help with tip build up.
I have also used the 4011 auto air reducer with good results.

I find with createx that you have to filter it. No matter how thin you have it. I use women's knee socks (hosiery) and medicine cups. You may be may be amazed on how much better it sprays and the nice coverage you get.
I've switched to using a lot of golden and the iwata paints. They flow so much better. More pricey per ounce but they eliminate lots of issues. However last I checked, the golden paints have changed some to more transparent instead of opaque.