Problems with HS airbrush

[Bstarr3]

I've developed an issue with my HS Evo CR.  I'm getting bubbling back into the cup as soon as air flows, which goes down a little with pulling the needle back, but it doesn't matter because the paint's splattered out of the cup and all over by then. Obviously some part is messed up, but my question is which part?  Do I need to replace the nozzle, needle, both? Are there any orings or seals that could cause this issue?  I just did a complete teardown clean with lt which did not resolve the issue. Thanks for input!

[Mark Harmsworth]

I have had this problem with my H&S Evolution from time to time. I've learnt that its fixable by taking it apart and putting it back together again - checking that's everything's done up tightly. So I guess air may be getting in where it shouldn't.

 

I now listen to the sound the airbrush makes before putting paint in. There's a noticeable louder air noise when it's not right.

Good luck

Mark

[bmwh548]

I'd try these (in this order):

Tighten the nozzle cover better (finger tight, don't use any tools).

Check the seal between the nozzle and the body of the airbrush. It might be damaged or simply worn. If you have a spare fit it and check the airbrush (just put some alcohol or even water in it so you don't make a huge mess everywhere).

Check the tip of the nozzle cover, there might be some paint buildup blocking the airflow, that would force air backwards towards the paint cup.

Worse case scenario: the nozzle is cracked and air is making it's way through. However if that were the case you'd get paint leaking out and you didn't mention that.

 

I've had that problem when the nozzle cover wasn't tightened properly. A minor tweak and it went back to normal.

[little-cars]

3 hours ago, Bstarr3 said:

I've developed an issue with my HS Evo CR.  I'm getting bubbling back into the cup as soon as air flows, which goes down a little with pulling the needle back, but it doesn't matter because the paint's splattered out of the cup and all over by then. Obviously some part is messed up, but my question is which part?  Do I need to replace the nozzle, needle, both? Are there any orings or seals that could cause this issue?  I just did a complete teardown clean with lt which did not resolve the issue. Thanks for input!

Bubbling back into the paint cup:

 

Split nozzle - Replace 

 

Air cap not tight  - Tighten

 

 Nozzle O ring not seating   - Can be ware or damage to the O ring ( you can turn it over to check if you don;t have a replacement to hand.)

 

Or it can be there is a little bit of dries paint/ grit on  the face of the airbrush where the O ring butts up to.

 

Paul

 

 

 

[Badder]

I have an Evo CR plus myself and yes, I often get bubbles in the cup.

 

After checking tightness and correct fits etc,  I can tell you now that 99 percent of the time it's down to poor cleaning resulting in paint build-up inside the nozzle. Yes, I do blow my AB  clear with water after every use, take it apart and check that the air hole in the nozzle is clear. You should be able to see perfectly circular daylight through even the smallest diamater nozzle, so if you can't, there's your problem right there. BUT, even if you CAN see perfectly circular daylight, there will be a build up of gunk in the wider parts of the nozzle and this will cause blow back. You need to clean the entire insides of the nozzle. There's a cheap little reaming tool you can buy online which works great (forget about the accompanying 'pipe-cleaner' brushes, they are useless) but I also use long plastic bristles taken from brooms/brushes. I use the 'snipped' ends as a scrapers. Whilst they take longer to scrape deposits from the insides of your AB and nozzle in particular, they aren't going to scratch or damage any of the parts.

 

Hope that helps,

Badder

 

[BIG X]

56 minutes ago, Badder said:

I also use long plastic bristles taken from brooms/brushes. I use the 'snipped' ends as a scrapers. Whilst they take longer to scrape deposits from the insides of your AB and nozzle in particular, they aren't going to scratch or damage any of the parts.

 

Hope that helps,

Badder

 

Nice tip Badder - I've been using very thin fuse wire & those dental brushes - to clean the nozzle - the thicker dental brushes are really good for cleaning the barrel area too.

[Chuck1945]

Late to the party, but ...  I have two H&S brushes, and always take them apart for cleaning immediately after use and would also claim to clean the needle/nozzle thoroughly. However I have also discovered that my “thorough” often wasn’t as thorough as I thought. I’ll echo what Badder said, 99% of the time I get blow-back it is because I really hadn’t done that good a job of cleaning.  Now my practice is to reassemble the brush and then run several drops of whatever thinner is appropriate for the paint I use through the brush to check that it really is clean and, unless I am using it again immediately afterwards, to also run thinner through it before using it to paint the next time.

Edited January 5, 2020 by Chuck1945
Adding a missing word I thought, but didn’t actually type

[Mike]

Most airbrush users find that their cleaning routine isn't good enough at least a few times before they reach one that's actually good enough.  I remember this myself, and I think I went through three evolutions until I was no-longer suffering from dirt related problems.  Grotty paint is your enemy - remove it!

[cmatthewbacon]

90% of the time I have this problem it’s because I haven’t tightened up the nozzle cap fully when I put it on. For nozzle cleaning I swab the inside with a gash paintbrush of lacquer thinner until I can see some bristles coming out the top, then put the sharp end of the nozzle into the plastic tube of my can of Liquid Reamer and give it a quick blast backwards, which usually brings out any crud loosened by the lacquer thinner. Admittedly this process is a lot easier on the Eclipse BCS, which has a decent size nozzle you can handle easily, than it is on the Evolution...

best,

M.

[Matthew1974]

I had this exact problem when I switched the tip, air cap, and needle on a new Paasche Raptor I had purchased.  Paint sprayed wonderfully when using the the 0.25mm components (air cap, tip, and needle).  I switch over to the 0.38mm components (never used) and as soon as I depressed the trigger, bubbles.  I rechecked everything and still bubbles appeared as soon as the trigger was depressed.  I notified Paasche and they sent me free of charge a new 0.38mm tip, air cap, and needle which was excellent customer service.  As soon as the components arrived I gave them a try and they worked perfectly.  Paasche even reached out to see if this fixed the problem which I notified them happily it did.  In my case I think it may have been some defect with the air cap not seating properly.  If your airbrush and its components are clean, I would suggest that there is a small leak somewhere that is causing your problem (something not seated flush) and maybe you should reach out to HS.  I'm not familiar with HS but if your airbrush came with different sized components try switching them out to maybe isolate what the issue might be.

[Sparkie]

On 05/01/2020 at 17:30, Mike said:

Most airbrush users find that their cleaning routine isn't good enough at least a few times before they reach one that's actually good enough.  I remember this myself, and I think I went through three evolutions until I was no-longer suffering from dirt related problems.  Grotty paint is your enemy - remove it!

Yep, exactly this. I have had my H&S Ultra 2in1 since November which I'm really pleased with, but saying that, also have nothing to compare it to.

 

I got used to switching needles for primer and top coats and give a good  cleaning between, which as @Mike says isn't ever a good enough routine for a while, but with practice it gets quicker. Although not having worked out pressure versus paint thickness properly yet, I still have to decide whether its a cleaning issue or not when i get poor flow results

 

What I have worked out though, is flushing through properly when switching between enamels and acrylics ( and all the differences in between). This was after i got instant gunk after I added acrylic paints to a spotlessly clean airbrush - or so I thought, but it still had some type of enamel thinners in the airbrush from the cleanup

 

[ckw]

One more thing to check - the threads of the nozzle where it screws into the airbrush. I found some paint build up here was causing a less than perfect seal - probably paint had got behind the oring

 

Colin