My iwata supernova is leaking from tip around threads. Just a drip of paint here and there and filling up behind cap.. I let one of the guys in my shop use my spray gun but I try to tell him just rinse it out after use but he sometimes insist on taking apart and will leave thinner or reducer just sitting in the gun and I tell him it eats up the seals and messes gun up.. do u think this is correct because right now I'm stuck between making him buy it off me being he mainly uses it because I use my sata... the gun was practically new and no issues and its grinding my gears that its spitting and leaking. I dont know to chalk it up to normal wear and tear or contribute the things I seen him do to it when he call himself cleaning it as reason why it's doing and spray gun only a year old maybe done been used less than 40 times

In the Iwata Supernova the only seal that's in contact with paint or thinners in the gun is the packing gland. If this is failing it won't cause drips.

Drips in this gun will come from a poor seal between the needle and inside of fluid nozzle (whether dirt, paint or wear) or from the thread on the fluid nozzle, either damaged or not properly tightened. An overtightened packing gland may also cause the needle to bind up and not seat properly in the fluid nozzle as could, but less likely, the air valve which may need cleaning and lubricating.

Recover the gun, clean and/or make whatever repairs are required and don't lend it to other people.