Iwata might have an adaptor.

This was the sticking point when I switched to CO2 way back when . I went to an auto repair supply house, not an autozone or clone (think the difference between Home Depot and the crusty old dudes at the local no-name hardware store) and brought the parts I needed connecting with me.

Crusty old dude behind the counter hardly batted an eye. He went in the back and came out with a cardboard box full of brass fittings. We fiddled with them for all of 15 sec. and done!

I'm guessing a compressed gas supplier, welding/beverage guys, can provide the same service.

good luck.
Mike

You can always get a compressor powerful enough to liquify air and then use a fractional distillation column to selectively obtain both carbon dioxide and nitrogen.

I came up with a solution, even though it's a bit inelegant. I removed the regulator and all fittings from my old compressor. It and the new Nitrogen regulator both have 1/4" NPT female threads. I just attached that to the new regulator. I'll order a proper NPT to airbrush hose fitting on Monday, but I can try out my new Iwata with the double regulator setup. I have Iwata, Badger and Paasche airbrushes. I'll get adapters for the airbrushes and just keep one hose for them.

I didn't have time for trying it out today.

I used CO2 for years before recently switching back to a compressor, it can cause some wierdness with acrylic and lacquer paints (it's so cold and dry it sometimes causes them to dry too fast).

A note on fittings, a lot of CO2 regulators have left-hand threads (I had a Norgren that did) so be aware if you go to start changing out fittings.