Iwata HP-CS problem

Most likely it is damaged. Hold it next to a light and use a magnifier if necessary to see if you can see any kind of dent or crack in the tip of the nozzle. They are very easy to damage.

I need to find a magnifier (I forgot where I put it).  Anyway, does a damaged nozzle cause paint to back-flow on the needle?  I don't recall ever seeing paint on the middle and rear areas of the needle.

From time to time I check the needle/nozzle fit on mine under my Optivisor strongest lens, using a lot of light. You could have a crack as JIm mentioned, or an out of round nozzle I suppose. Does sound like the needle isn't seating.

If you have a Hobby Lobby nearby, and find you need one, most of them stock spares. At least the ones around here do. Just make sure it's the right one for the HP-CS, they stock for the Neo's and stuff too.

The nozzle hit the bathroom sink, bounced and fell into the hole.  Anyway, I found a magnifier and examined the nozzle.  I see nothing inside the nozzle but the tip looks slightly bent.  Will go to HL.

I'm curious as to why a damaged nozzle causes paint to backflow on the needle. Does anyone know?

Paint backflow sounds like an un-related problem. Sounds almost certain that the nozzle is distorted enough to keep the tip of the needle from seating fully.

I always take out the needle through the front opening of an AB. Since the needle wasn't fully seated, there must have been excessive paint inside the front area of my Eclipse. Probably, that's why I saw paint the rear part of the needle.

I'll investigate more, but a sudden, unrelated paint backflow problem is unlikely.

I learned a lesson. I will never disassemble an AB at a bathroom.

Sorry about the damaged nozzle, but you found the problem and it is repairable without to much fuss or expense so that is good.

I have back-flow issues and questions too, I may post a question in a new thread. If you never noticed yours until your tip was damaged, that just makes me even more curious.

I bought a .35 mm nozzle for $17 at HL and everything works as expected!

I cannot believe that dropping the original nozzle damaged it somehow.  Is a nozzle that fragile?

Yep. I've damaged the nozzles and the needles when I did my best to be careful and couldn't even remember dropping them. You can bump the AB against something hard enough even when you don't realize you did it and that's all she wrote.

Glad you got it sorted out, Chris.

I've often wondered just how fragile that nozzle is. Sorry I had to learn the answer at your expense, though.

I examined the damaged nozzle opening with my Optivisor at 10.5x. There is a barely visible microscopic dent on the opening. It's amazing that such a tiny imperfection screwed up the AB.

A lesson learned, though. I'll NEVER disassemble and clean my ABs in the bathroom.

I figured it probably had a dent since you dropped it. Cracks usually occur when you push the needle through too far. Not trying to be discouraging here but I'll about guarantee that you'll damage it again at some point. They are just too easy to damage especially the more fine they are. It might not be a bad idea to get a spare nozzle and needle. You don't need a huge supply of them just one extra of each for when you are ready to put that finishing coat on a build and the AB doesn't spray right because one or the other is damaged. Use an airbrush long enough and you'll have to replace those items from time to time just because of unexpected damage.

Which reminds me, I have spares for my Iwata but haven't gotten around to getting them for my other AB that I use all the time. Thanks for the reminder, Jim. Good tip. (no pun intended)