Now what am I doing wrong?!

[stona]

I also pull and push back from the back of the AB. Harder and Steenbeck (who made my AB) advised me to do that "because the end of the needle [non- pointed end] has stamped on it a code giving the size of the needle, and putting that through the seal in the middle of the AB might damage that seal" (or similar words). Under a magnifying glass the stamping process seems to be a mechanical stamp (like in an industrial steel forge) which seems to displace metal up, and if so, that raised metal could scratch the seal.
The argument that I have heard for pulling and pushing back from the front is that paint cannot be dragged through the seal and therefore into the rear part of the AB.

That makes perfect sense for the H+S brush, you definitely don't want to damage that seal (at the back of the paint cup). There's nothing stamped on the 'blunt' end of an Iwata needle, but pushing that through the seal, rather than the taper of the needle end, might still be a bit of a risk.


Before I pull the needle out through the back I give it a little back and forth and most of the paint in that area visibly comes off into the thinners. I don't think much gets pulled through to the rear of the brush, though to avoid this was the reason I've been given for pulling the needle through the front too.


It's not for me to tell anyone what to do with their airbrushes, but I've been using mine like this for many years and they work as well today as when I took them out of the box


Cheers


Steve