I have a gravity fed spray gun that I just can't get to stop spitting. I've got acrylic gloss in it (1.4mm nossle) and I've cleaned it within an inch of it's life yet it's spitting like a rabid camel!

what am I missing?!

should I clean it out with thinners first?

maybe the thinners are affecting the acrylic (if it is water based)??????? or the paint is still to thick
matt

Sounds like needle is not fully returning after action.

make sure the fluid tip is tight and the needle is seating properly.

You could also check the gland nut on the main needle is not too tight and stopping the needle from returning. Or the spring tension on the back of the needle is not tight enough. Or the needle is not clean along the shaft and is gripping on the gland seal. So many reasons, fixes etc. If full disassemble, clean and reassemble give the same problem, then there must be a part needing replacement, or a different adjustment.

sorry, I didn't make myself clear. it spits rather than spraying the paint evenly. the paint is reasonably thick, but I thinned it down a fair bit I thought. does it need to be thinned more?

just pulled it apart again and cleaned it within an inch of it's life. not sure if it's any better though.

Hi Pete. Acrylic needs to be thinned 100 parts paint to 150 parts thinners. So 1 litre of paint when thinned is 2.5 litres, so it's pretty runny. As for the 1.4mm gun, that's a little small for acrylic. It's more of a 2 pac nozzle set up. I use 1.7mm for acrylic. but seeing as you said you've thinned it right out it shouldn't be the problem. Make sure the breather hole in the top of the cap isn't clogged. Like hellbus says, there are so many things that can upset a spray gun.
Good luck.

thanx mate, I got it right. used a 1.8 nozzle and thinned it right down until it was runny enough. all good now.