Splatter issue

[goggsy]

I’m hitting a problem with my usually reliable Iwata HP-CH and although I think I know what the cause is I’d like to run it by the members if I may. Basically I’m getting terrible splatter and finding it really hard to get good fine lines. I usually work with either Tamiya acrylics or Mr Aqua Color and thin with either IPA or cellulose. Neither thinner makes a difference and nor does the amount I put in - even when the paint is thinned to the point of being unusable it’s still farting about. Pressure doesn’t make much difference either although higher seems slightly better. 

 

I work in my outbuilding and it’s quite cold in there as it’s not usually heated. Today I tried warming the pots of paint on a radiator for quarter of an hour but there was still some splatter. I’m wondering if the temperature of the metal airbrush is contributing to the problem and whether I should dunk it in warm water for a bit before I start?

 

It’s also still running on the original needle and nozzle which is getting on for ten years old now. Obviously I can replace these but I haven’t noticed a problem until recently and would like to eliminate the paint as a possible cause before I spend the thick end of £60 on a new nozzle and needle. What do people think?

[bmwh548]

I would remove the nozzle and give it a good clean. Because of it's size it can get clogged up up to the point where thinner will flow almost normally, but the paint mix (being much more viscous) won't.

I've had a similar problem a few weeks ago with my primer airbrush (Chinese, similar nozzle design), it would just spit the primer out. Took the nozzle out and found a hair from the brush I use to clean the airbrush with stuck inside. Cleaned it up, put it back together, works just fine.

If you go for the deep clean make sure the air holes are clean, the nozzle isn't cracked and the seals are still in good condition.

[Steve Noble]

Most issues of poor spraying are either a cleaning issue, worn/damaged parts or incorrect thinner/thinning. I would give the whole brush a strip and thorough clean and check the parts while you're doing that. Personally I would also use the recommended thinner. I don't know why people use ipa to thin paints? It evaporates so quickly the paints are dry before they hit the surface. Same with cellulose on Tamiya acrylics, it dries too fast, sometimes in the air whilst the paint is travelling to the surface, something you don't want to happen. I'd use the correct Tamiya X-20a thinner and see if that helps. Otherwise it could be a cleaning or a broken parts issue..

[goggsy]

Quick update - I replaced the (eye wateringly expensive) needle and nozzle and it’s all good now. I also replaced the nozzle cap which had picked up a dent somewhere and may have been throwing the spray pattern off a bit.

For info when I use IPA I cut it with flow enhancer to prevent tip drying, seems to do the trick usually,

[nheather]

Out of interest, did you just replace both needle and nozzle together or did you do them one at a time to find out which part was the culprit?

 

Cheers,

 

Nigel

[goggsy]

I just went for both as they were getting on for ten years old and were pretty worn. If I’d just bent the tip of a relatively new needle that would have been different but I didn’t see the point in farting around.