Hey all,
I just got a new Iwata Eclipse CS last week. I have been practicing with it off and on since getting it. Really liking the results so far and am really impressed with the quality of parts, ease to clean and overall feel. One issue I'm having though is that I find if I'm anywhere above lower pressures (i.e. 9 psi) then the spray pattern slowly shrinks to nothing after a few seconds. I believe im mixing at no more than 70/30 thinner to paint ratio here. This is mostly noticeable with smaller detailed lines too. Its ok when spraying large diameter sizes, only medium to finer lines are a problem. When trying to do camo lines the spray will fade and I will have to re-tweak the trigger and gradually get a flow going again. Sometimes a larger amount will flow out since the paint amount to trigger pull ratio seems to always change. Gets pretty irritating after having to do this over and over. Is this just the nature of these brushes? Everyone talks about normal pressures for these brushes being in the 15+ psi range, I can only use these kind of pressures if I were laying down a large and heavy coat. To exercise any amount of precision or control necessitates in really low pressures. So is this something I just need to get used to or could there be something else working against me? Thanks for any help you all can offer!
Steve

What paint are you using? I spray only Tamiya acrylics. I use a 60/40 thinner to paint ratio and have no problem spraying fine lines at a psi < 10 with my Eclipse.

The paint is drying on the needle and restricting the paint flow.

What type of paint and thinners are you using?

If it is acrylic you should try some retarder of flow improver.

You should also use a soft brush soaked in thinners to carefully wipe around the needle tip periodically.

Forgot to say, im using tamiya acrylics w the tamiya thinner. Trying a little windex or acryl retarder helps a bit but not much. I could just be expecting too much of the brush for higher pressures. What im doing right now is the camo line work for my 1/35 panther kit so I guess you could consider this small detailed work. Is it safe to assume that when your pressures are too high for the current paint flow it will dry around the needle and taper off quickly?

Personally i think you've got the pressure too low. The air isn't blowing the paint away, causing it to gather and dry at the tip.

Try using a retarder, 15psi +, then use your skill to control the paint flow. I think you're trying to slow the amount of paint by lowering air flow at the moment. I can get fine lines with my old badger at 20psi, but the adjuster on the end which restricts paint flow helps to make sure I don't get a heavy handed blob of paint!

Hope that helps.

A lot of people expect to get an airbrush and get instant magical results. It's really not simple at all.
Airbrushes overall are delicate instruments which require a lot of practice to master, and a good bit of experimenting along the way. I only use Testors enamels with mineral spirits thinners, so I'm no help on acrylics at all..but the only time I get the issues you describe is with paint too thick and air pressure too low.
Even with practice and perfect set ups, you STILL will need a scrap card to "clear" the brush and adjust your settings while painting. An airbrush is not a push button device, turn key and drive, no no. It involves skill and a bit of talent and a lot of flexibility and willingness to try anything..adapt and overcome. It takes time and sorry, some used up materials to learn.

Also, if you don't mind my saying. You have to set your regulator on the compressor to keep the air pressure moving through the line at whatever psi you want it to be, while you are depressing the AB trigger. In other words if you set the regulator at 9 lbs. while the system is not moving air, you will loose a pound or so through the length of the hose, moisture trap, and the brush itself.

You have to compensate for the distance that the air has to move until it actually gets to the tip of the needle itself by adjusting the pressure while the trigger is depressed and air volume is moving along the whole length.

Just watch your guage, and adjust the pressure to the desired psi, while your spraying. That's how I was taught to do it. That is a fine tool that you have, I bought an Iwata HP-CS and I have fallen in love with it. It is light years ahead of my old Badger 150, and I thought that it was the bomb before I bought the Iwata.

Hope this helps you.

Thanks for all the comments here, guys. I definitely am aware of the black arts that is airbrushing. I knew this wasn't going to give instant awesome results without some trial and error. I've been using airbrushes occasionally since I was in middle school with my old badger 250 and mini bottle of compressed air. What a total piece of sh%t that was, lol! Im 37 now and using them again after a LONG hiatus. My main problem is im so used to my Paasche millennium and not used to varying my tried and true technique. Going from a siphon to a grav fed is a big step alone. It really just seems like anything above 10 psi will see the paint stream shrink slowly to nothing. That is unless I go past 30-40% of trigger pull. Putting the psi to 15-20 sees the paint stream just shrink almost instantly (10-20% of trigger pull). Im wondering if the needle/tip (.35mm) is too small for the tamiya acrylics im using. All this doesn't mean the brush is unusable, just a slight pain in the as@. What im after is if this is something I need to get used to and it may be.

I will say this, and maybe it will help you some. I noticed that when I changed over from a bottom feed Badger to this top feed Iwata. The Iwata seems to be much more conservative in consumption, as far as the amount of paint material that it takes to do the job. The Badger was a paint HOG, and this Iwata does a lot more work with much less fluid.

I also have the 5 mm conversion needle assembly, but I haven't used it yet. I ain't nobody,..and I ain't even good at this stuff, but I can set my regulator to keep a steady flow of 12 to 15 psi and this brush will constantly draw, and write pencil line width words and sentences as long as I have the right mix in the bowl.

Make sure you don't have any restrictions in your air flow, nothings bent or broken, and check that your mix is right. Also, if you screw the nozzle end cap off of the brush, you can get right down very close to your work, and that will allow you to get very thin lines with low pressures.

Good luck.

I use an Iwata HPC+ with a .3mm needle, and this handles tamiya paint just fine, so a .35 will also be fine.

You should be able to spray at quite low pressured for fine lines, especially if you are thinning the paint so much.

Since you've been using a bit already, have you taken the fluid nozzle (the very tip that the needle protrudes from) off and really cleaned this out? If you haven't been taking this off and just relying on blowing thinners through, you might have a paint build up in the nozzle.

You could always try lacquer thinner, it's sort of self-cleaning

Steve, try running some plain water through the AB at the pressure you want to spray at. If the line does not go away, then your problem is most likely paint drying on the tip. Jeff

Is it OK to spray lacquer thinner through an HP-CS? I remember reading the HP-C Plus has tougher seals to handle harsher solvents like lacquer thinner, and the HP-CS may not? Really been wondering this, as I've just been shooting Tamiya + Alcohol through it since I got mine.

The HP-CS should be fine with lacquer thinner because many enamel users use the AB. However, since you spray Tamiya acrylics, why bother with lacquer thinner? Windex removes Tamiya acrylics as effectively as lacquer thinner.