HP-CH Sputtering paint

[Satch]

I know this problem has been discussed before but I couldn't find any of the old threads. Sorry.
I have an Iwata HP-CH that I've been using for about two months. Until recently, all was well and it was working like a well oiled machine. About a week ago it started "sputtering"... you know, spraying paint in irregular spurts. It now paints in dots and dashes instead of a nice straight line. I have cleaned it more times than I care to count. All parts look spotless. I use two water traps. One on the regulator and one in line. I even have a fan blowing on the compressor to cool it somewhat. The hole in the cup cover is open and the needle seems to seat in the tip perfectly. I'm using Com-Art paint thined with plain distilled water 50-50.
Does anyone have a clue as to what else I can try to make it spray smoothley?
Thanks,
Satch

check th noozle with a magnifing glass it very well could be cracked, split and you can't see it
have you changed the nozzle to see if it made a dif. ?

[zero420]

i agree with don check nozzle had same problem with my bcs also ha a slight bend on the very tip just my 2 cents i have a question though u thin down com-art 50/50 isnt com-art real thin as it comes

zero420

[Satch]

Originally Posted by donjohnson

check th noozle with a magnifing glass it very well could be cracked, split and you can't see it
have you changed the nozzle to see if it made a dif. ?

I just looked at the nozzle (tip) under a powerful magnifying glass and see no cracks or problems with it. However, I put the needle in the nozzle (tip) to try to feel around for any possible obstructions and I felt what seemed to be a very small ridge that goes around the entire inside about half way in. Is this normal? Perhaps made during manufacturing? The ridge feels to be very uniform all the way around.

ZERO: I only thin the Com-Art when I practice. I guess I'm a "tight wad" and try to stretch it to make it go a little longer. But since I've been having the sputtering problem I thined it to make extra sure it wasn't the paint causing the problem.

Satch

[Midnight]

did u try shooting just water thru it to see if its the same?
if its not blocked or leaking from cracks possible the air isnt hitting the correct place to create the suction to pull the paint out.

[Snuff]

Satch,
try sharpening a tooth pick to a very fine point ...soak it on alcohol and twist it into the nozzle.(gently) While the toothpick is still in look at it with the magnifying glass to see if any crud came out or if the TP forced a crack open. I had this happen with mine and under a toolmakers microscope it showed a crack.

Hope this helps.

[Satch]

Thanks for the replies and concern guys.
Midnight: I didn't try just water but I really thined down some Com-Art paint, which is already very thin, and it was still sputtering. I didn't use just water because I thought I wouldn't be able to see well enough to know if it was still sputtering.
Snuff: That nozzle is so small I doubt if I could get a tooth pick small enough to go in. However, I did use the needle itself and I couldn't see any cracks nor did any crud come out.
When I run my fingernail over the needle tip it feels a little rough. When I look at it under the magnifying glass it looks clean. So just to make sure there was no coating of some sort, I took an exacto knife and gently scraped the tip, as if I were trying to shave it down. After a few passes of the exacto knife the needle felt much smoother and now the brush is spraying fine. No, I haven't shot anything through the gun except Com-Art and Goldens paint and cleaner such as Badger Airbrush cleaner, denatured alcohol and windex with out amonia. I also lightly oil the needle each time I clean it and put it back in the brush. I'll keep you posted if it happens again.
Thanks again to all who have responded.
Satch

[chuck mullins]

I Spay Lac. Thinner Thru It For About 30 Seconds That Usally Gets Any Dried Paint That Stays In The Noozle, Then Clean It And Sray Water For 1 Minute.

[Satch]

Originally Posted by chuck mullins

I Spay Lac. Thinner Thru It For About 30 Seconds That Usally Gets Any Dried Paint That Stays In The Noozle, Then Clean It And Sray Water For 1 Minute.

Thanks Chuck .... I did manage to correct the problem but if it happens again I certainly will try your suggestion. It sounds a lot easier and quicker.
Satch

[Joyce]

Satch, I have been battling the same problem today with my brush. I even got my Paasche out and tried that also and it was doing the same thing and like you did I have cleaned them both too many times to count. I am going to do everything suggested in this thread, if that doesn't do it. I am gonna sit down and cry. Wish me luck.

[Satch]

Originally Posted by Joyce

Satch, I have been battling the same problem today with my brush. I even got my Paasche out and tried that also and it was doing the same thing and like you did I have cleaned them both too many times to count. I am going to do everything suggested in this thread, if that doesn't do it. I am gonna sit down and cry. Wish me luck.

Joyce .... Good Luck!! I just think that once in a while a little chunk of dried paint seems to hide some how inside the brush and it just takes luck and persevering to get it. Also a good soaking in warm water and dish soap might help ... I also use denatured alcohol a lot. And I only use water based paint .... Hate to think of the problems solvent based paint causes.
Anyway ..... keep at it but if you start getting frustrated just walk away from it for awhile. Go watch TV .... (But not the news)....

Satch

[jack024]

I used Iwata HP-C, if color dry in nozzle I soak it in alcohol.
for com art color I mix with golden airbrush medium 1:1 and clean up with cleaner (2water, 1windex, 1simple green).