An invisible H&S problem.

[Jim R]

I have an H&S Infinity CR plus. After many years of trouble free use, mostly with the 0.2 nozzle, it's decided to be awkward. After a longish air brushing session I noticed air bubbles in the paint cup. Stripped the airbrush down as I've done many times, good clean and reassemble. Still bubbles. Another strip down, same result. Third strip down and replace seals, same result. Examine needle and nozzle with magnifier, looked fine. Replaced 0.2 with 0.4 needle set up and behaved perfectly.

Hence my thread title. There is nothing I can see wrong. The fault is invisible. Anyway I've bought a new 0.2 set up from John as the fault must be with the original 0.2 needle and/or nozzle.

Frustrated, and poorer, of Shropshire

 

[BarryW]

This does happen and I think you have done the right thing to solve it.

 

[Scratchbuilder]

Dear Frustrated of Shropshire,
What may be the problem (from sad experience) could be a build up of material in the small part (Nozzle) that the needle fits into.
I know you said you had gone through the cleaning process (I did the same). But I purchased another needle assembly and forgot to remove the nozzle, so in effect the problem was not solved.
I then did a full strip down and dropped the lot into a pot of IPA and left it for 24 hours, then used an old needle to really poke through the hole and was surprised at the muck that came out, again despite the clean before. Assembled the new neddle assembly, and tried it, then did the same with the old assembly and both worked fine.
Sadly I was succumed to the Iwata clan by discounts and freebies, and this now is where I remain...
Mike the Iwata groupie.

 

[Tim Marlow]

Absolutely agree with Mike. Think about it….air in the paint cup means air can’t get out of the nozzle end. If changing the nozzle and needle cures the problem, then the problem isn’t in the airbrush body and must lie with the original nozzle and needle. The needle is easy to clean and check, so is unlikely to be the culprit. However, give it a good clean with a fold of kitchen towel moistened with airbrush cleaner or cellulose thinner. That leaves the nozzle. 0.2mm is pretty small, so even a thin, almost transparent paint film could cause this problem. I would soak the nozzle in cellulose thinners at least overnight to soften the blockage, then clean through it by scrubbing with the bristles of a stiff brush. If this doesn’t work, repeat the soak and scrub until it does.

 

[JR]

Thinking about the bubbles, Tim's and Wibbles Ideas seem right .
I gave up with H&S after the trouble I had with needles and tips being as they were unmarked .
Now like my cheop Iwata Neo .

 

[boatman]

WELL im sorry to say that all the troubles you guys have with these air brushes im glad i dint buy one as to me it sounds like you guys spend as much time strippin down the A/B as you do paintin
chrisb

 

[David Lovell]

WELL im sorry to say that all the troubles you guys have with these air brushes im glad i dint buy one as to me it sounds like you guys spend as much time strippin down the A/B as you do paintin
chrisb

Na use it flush it through with a decent tool cleaner ,chuck it back in the box till next time.

 

[BarryW]

WELL im sorry to say that all the troubles you guys have with these air brushes im glad i dint buy one as to me it sounds like you guys spend as much time strippin down the A/B as you do paintin
chrisb

No Chris. They are not really that much trouble at all. Well worth it.

 

[Andy T]

I agree with Barry. Needles & nozzles are classed as a wearable or replaceable item, like the brakes and tyres on a car, so changing them after "many years of trouble free use" shouldn't be seen as a bad thing.

The nozzle could possibly have developed a hairline crack, almost impossible to see, but enough to allow air back past the needle.

H&S are actually changing their needle/nozzle sizes with the new generation of airbrushes they are releasing. Typically they are backwards compatible with existing brushes though and will be all that is available from now on.

0.2 will become 0.28, 0.4 will be replaced with 0.45, both having a new taper design which will keep or even increase the fineness of the paint stream over the previous size, while increasing robustness and suceptability to clogging.

(according to the blurb )

 

[Gern]

I agree with Barry. Needles & nozzles are classed as a wearable or replaceable item, like the brakes and tyres on a car, so changing them after "many years of trouble free use" shouldn't be seen as a bad thing.

The nozzle could possibly have developed a hairline crack, almost impossible to see, but enough to allow air back past the needle.

H&S are actually changing their needle/nozzle sizes with the new generation of airbrushes they are releasing. Typically they are backwards compatible with existing brushes though and will be all that is available from now on.

0.2 will become 0.28, 0.4 will be replaced with 0.45, both having a new taper design which will keep or even increase the fineness of the paint stream over the previous size, while increasing robustness and suceptability to clogging.

(according to the blurb )

Does that mean I won't be able to get needle/nozzle spares for my existing A/B in future?

 

[Jim R]

Thanks guys. It's not a problem with the airbrush itself because it works perfectly with the 0.4 needle/nozzle.
It could be simply wear and tear, the 0.2 has been used a lot. It may be a hairline crack in the nozzle. It could well be paint build up in the very small nozzle. I'll have another good clean and see how it goes.
Thanks for your thoughts. I really appreciate them. I suppose I've been lucky in that I've never had any problems with my airbrushes and I've put acrylics, enamels and lacquers through them. I rarely get any tip drying or blocking and have a cleaning routine that's quick and has worked over the years.
Thanks again guys.

I have the H&S and an Iwata. I do actually much prefer the Iwata.

 

[Tim Marlow]

Ignore what I wrote above, it’s basically rubbish . After reading Andy’s text above, I thought about what I’d written. What I’ve written is illogical and is based around a faulty premise, that air and paint are mixed before they go through the nozzle. I was having a thick moment, not for the first time. They are not! Air and paint mix at the needle tip! If they didn’t we would get air in the paint cup every time we stopped the paint flow! The description I’ve given would be true if you were getting no paint out of the brush, but not for the problem you are experiencing.

What that means is this! Air in the paint stream means there is a leak between the paint path, and the air path. This is almost certainly due to the way the nozzle is seated or the nozzle itself, because they are the bits you take out for cleaning!

There is a good short video here explaining how the airbrush works. Well worth the couple of minutes it takes to view.

how does an airbrush work - Google Search

 

[Andy T]

Does that mean I won't be able to get needle/nozzle spares for my existing A/B in future?

According to H&S they are backwards compatible, as I mentioned. That's one advantage to getting into the H&S family as parts can generally be swapped between older & newer models, as well as up & down the range.

So once the stocks of 0.2 have run out you'll simply get the newer sized equivalent.

 

[boatman]

WELL Guys many thanks for your A/B TIPS an to me you guys are the exsperts with exspensive A/B an if you get on ok with them then great but ive used a cheap A/B my boaty freind let me borrow an in my opinion yes i know it was a cheap A/B an you get what you pay for but usein his A/B on that K/H jag kit put me right off havin one as the niose the commressor made was terrible an it took a while to build up air pressure an kept conkin out an well im a patient man but after usein that id had enough an im nr the end of my modelin life so no point in buyin an exspensive A/B is there this is just my opinion an yes get the violins out lol
chrisb

 

[Scratchbuilder]

Ignore what I wrote above, it’s basically rubbish . After reading Andy’s text above, I thought about what I’d written. What I’ve written is illogical and is based around a faulty premise, that air and paint are mixed before they go through the nozzle. I was having a thick moment, not for the first time. They are not! Air and paint mix at the needle tip! If they didn’t we would get air in the paint cup every time we stopped the paint flow! The description I’ve given would be true if you were getting no paint out of the brush, but not for the problem you are experiencing.

What that means is this! Air in the paint stream means there is a leak between the paint path, and the air path. This is almost certainly due to the way the nozzle is seated or the nozzle itself, because they are the bits you take out for cleaning!

There is a good short video here explaining how the airbrush works. Well worth the couple of minutes it takes to view.

how does an airbrush work - Google Search

Not to worry Tim, we read between the lines and came out with the correct answer..

 

[Gern]

WELL Guys many thanks for your A/B TIPS an to me you guys are the exsperts with exspensive A/B an if you get on ok with them then great but ive used a cheap A/B my boaty freind let me borrow an in my opinion yes i know it was a cheap A/B an you get what you pay for but usein his A/B on that K/H jag kit put me right off havin one as the niose the commressor made was terrible an it took a while to build up air pressure an kept conkin out an well im a patient man but after usein that id had enough an im nr the end of my modelin life so no point in buyin an exspensive A/B is there this is just my opinion an yes get the violins out lol
chrisb

Sorry Chris, but that's why folks go for the more expensive equipment. I'm not saying they're perfect but they're much less likely to suffer from the issues you describe. I started with a cheap compressor and really cheap A/Bs and had endless issues with them - so much so, I almost gave up on using A/Bs all together.

I have had some problems with my set up, but I'm sure I can put all those down to user error.

 

[boatman]

Sorry Chris, but that's why folks go for the more expensive equipment. I'm not saying they're perfect but they're much less likely to suffer from the issues you describe. I started with a cheap compressor and really cheap A/Bs and had endless issues with them - so much so, I almost gave up on using A/Bs all together.

I have had some problems with my set up, but I'm sure I can put all those down to user error.

OK Dave point taken
chrisb

 

[Tim Marlow]

Sorry Chris, but that's why folks go for the more expensive equipment. I'm not saying they're perfect but they're much less likely to suffer from the issues you describe. I started with a cheap compressor and really cheap A/Bs and had endless issues with them - so much so, I almost gave up on using A/Bs all together.

I have had some problems with my set up, but I'm sure I can put all those down to user error.

Agree with that Dave. Best upgrade I made was to a better compressor. Constant pulseless airflow and much better control.

 

[Jim R]

This does happen and I think you have done the right thing to solve it.

Well Barry you were right. I wish the problem had been simple but no!!
I took the needle and nozzle, I examined it with a magnifier, I took off the seals, soaked the needle and the nozzle in Liquid Reamer, gave them a session in the ultrasonic cleaner, put in new seals, lubricated everything and carefully reassembled........ and did it work - NO!!!! 'Twas just the same
New 0.2 nozzle/ needle set arrived this morning from John. The usual keen price and excellent service. Fitted into the airbrush - worked perfectly
So all's well that ends well. I haven't a clue how I caused damage or what the damage was but yes Barry - you were right.