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Iwata CM-SB v2.0 Notes

These are from a novice artist, yet twenty year veteran of airbrush foibles.

I. For those with experience using the v1 or other CM brushes:

1. Biggest issue: trigger assembly. Pull out your parts guides to follow along:

a. The change to the single-piece auxiliary lever/chucking guide assembly brings the Custom Micron series in line with the rest of the Iwata catalog, but not in a good way. Where many of the other brushes, by way of needle spring tension and/or air pressure under the trigger can brute force their way into a closed nozzle/needle combination, the Microns live and die by this combination. Where the prior two-piece assembly would consistently get you a tight seal at the front end so long as you had the spring adjuster in something other than limp-noodle tension, the single-piece has the propensity to bind, meaning that lubrication status of the joint, along with the chucking guide as it slips through the adjuster in the back, is vital. Too much or too little will cause a bind, where it used to simply work, but feel a little resistant. The guide/adjuster shouldn’t be susceptible to over-lube, but the auxiliary lever side will be; it’s especially troublesome because excess can gum up the air piston.

b. The change to the taller “ergonomic” trigger is a wash. The old “low” trigger was a bit wider, and while the dimple wasn’t the most comfortable for those who would mash their index finger’s pad into the divot, it was just fine for those of us who rest the side of the knuckle across the trigger and use that small action to actuate the arm. For those who wanted something taller, the Kustom series single was available as a replacement.

With the new model, we surrender a bit of overall size for some extra height, which thereby increases overall flow. I’m not sure I care for that half of the trade. I would consider the Blair Soft Spring/Zsolt Soft Spring (available in the US at schoolofrealism.com, and in Europe at foxystudio.com) mandatory. I’ll likely swap the original trigger in when I have the time.

II. General

1. Trigger group, again: remember how I mentioned that the closure is no longer guaranteed unless the auxiliary lever/chucking guide was working properly? Now you have one more thing to add to your “why in the hell is this thing sending pigment when I’ve returned the needle to idle” troubleshooting bin. And it’s this, more times than it’s not.

2. Things to do:

a. As always, Iwata has sealed the nozzle group to the body, and tightened the spring guide and air valve set with a death grip. You’ll want to wrap your Vice Grips up six/seven times with electrical tape before popping these all loose, and you *want* them removable. The first makes cleaning the nozzle a breeze with an ultrasonic cleaner, the second gives you access to the auxiliary lever assembly for cleaning off too much lubricant (because you will the first time in), and the latter lets you chuck the whole body in the drink for a good cleaning should it need it, without blowing those o-rings and valve assembly by getting it wet.

b. Insert your needle the correct way. Needles get damaged when installed from the back, impacting the trigger (push it down) or the packing screw (if you’re pressing down and bending it, instead of purely aft). Instead, you can save yourself the trouble by installing it “backwards”- ie, from front to back. Remove the head group (it’s now finger tight, so this is easy), and make sure the chucking nut is loose. Insert the needle blunt end first (duh!), and press the trigger as it travels through the body. Continue until only the point is showing out of the head-system packing o-ring, then screw down the chucking nut lightly. Install the head system to finger tightness, loosen the chucking nut, and push the needle forward into the nozzle. Stop when you feel metal-to-metal contact, and tighten the chucking nut. Done, and you didn’t bang the point twice on the way through.

c. Lubricate the head-system packing o-ring. When you start getting in the habit of removing the head assembly to clean, the front o-ring can start allowing air to flow back into the body. A bit of Super Lube can fix this (and it’s likely the only o-ring in the works you want SL to touch, for the fact it tends to gum them up. Having this be a bit sticky is to your long term benefit). You’ll know this is the case when you’re still getting bubbles in the cup after you’ve cleared every air flow channel, hole, and sealed up the threads.

d. When changing colors, clean the cup, then clean the nozzle.  The routine is generally shove some cleaner/solvent into the cup, swish it around with a swab/brush, then run the brush at high-flow into a trap/paper towel.  This is backwards.  Think about it- while you may have a bit of dried paint at the nozzle/tip, a cursory glance into the color cup shows a ton of dried residue all around the sides.  Dropping solvent into the cup doesn’t break this back down into a fluid, but simply breaks the bond it has to the side of the cup, floating it around, and allowing it to be drug through the fluid passages to join the rest of the garbage in the nozzle tip.

Thus, the safer bet is to fill the cup once with solvent/cleaner, use your swab/brush to scrub some, then “brew” the cup (squeeze your fingers at the tip to cause blowback into the cup) *without* allowing flow to exit the tip when starting- ergo, squeeze at the tip prior to pressing down on the trigger.  Do this once with solvent, and discard into a spare Dixie/Solo/whatever cup you have at hand for the purpose.  Fill with water, “brew” again, then dump.  Keep “brewing” with blowback and dumping the water until the water stays clear during the brew.  If you see lots of residue remaining at the base of the cup after a few doses of water, add solvent/cleaner one more time, then continue on the water regimen.

Once the cup stays clear with water, then it is safe to progress cleaning the tip by sending cleaner (rather than cleaner plus a bunch of paint residue) through the body.

e. Keep the air on.  If you’ve read any material on the subject of using the airbrush authored after the 80s (back when everybody but the t-shirt players were hacking their way through their days), you’ve heard those words- likely from Terry Hill himself.  It’s true.  90+% of the flow problems you will encounter with an airbrush will be caused by poor technique, stopping the flow of air before the flow of paint.  “Basic” proper technique starts with air, then flow of paint, then stopping flow, then stopping air, as is demonstrated in all the “how to airbrush” DVDs and such.

However, watch a *good* artist, and you’ll note how often they take their finger off the trigger with gun in hand- it’s rare.  The brush is spraying air more often than its not, and this reaps huge benefits- it keeps paint from jamming at the nozzle, causing an uncontrolled rush or dry fleck to hit the substrate next time you trigger down.  You’ll note issues with the color cup cap off before they happen as you spy the bubbles building if you’ve got an air issue.  If the gun is flowing after bringing the trigger to idle, you’ll know it immediately.  If condensation should suddenly happen, or you suffer a pressure loss, you’ll know it- the latter is especially useful if, God forbid, your compressor dies mid-session, because your cleaning process without air *will* be better having the channel been cleared.

If you’re an old hand and have never picked up on it, coming to a Micron for the first time, or even just getting into airbrushing, period- make it a habit.  If the brush is in your hand, you should hear it, rather than feel it.  If you don’t, or it doesn’t sound consistent, you’ll know something is wrong.   Having some unexpected paint or water show up all over your hand, workspace, or clothes is far better than having it show up all over your project.  Consistency is everything at 0.18mm.

3. Things to buy:

a. Ultrasonic cleaner. Saves your sanity when it seems like there’s something gumming up the works on the nozzle side of the brush.

b. A wax toilet bowl gasket. If you’ve never owned one for putting beeswax on threads, you’ll only need one, ever. If you already have one, that one will do. Don’t overtighten your threads trying to stop leaks- apply wax in the threads, and finger tighten.

c. 60x Magifier with light. Iwata pawns these off along with their cleaning kits. If you already have your assortment of brushes and whatnot, go on eBay, search for “60x currency magnifier LED”; it’ll run you $5 at most. This will let you see up close and personal on the nozzle end for anything jamming up the flow between the needle and nozzle, search for damage, and make sure that the seal is solid.

d. Oral swabs (unflavored). Most everybody uses cotton swabs with the plastic, rather than cardboard sticks. Problem with them is that individual cotton fibers can slip into the nozzle/needle joint or nozzle cap assembly and damage the flow; if its a single fiber, the flow will be greatly diminished, but you won’t be able to *see* it, and cleaning may not get it loose immediately. Oral swabs, rather than cotton, have sponge ends which won’t break down.

e. Tamiya Extra Small Triangular Swabs. While the end is cotton, this will clear anything from the nozzle cap hole. However, *only* use with cap removed from brush. You could even use this to polish said hole hole with some ultra-fine diamond polish (hint; also- note I said NOZZLE CAP, not NOZZLE).

f. Soft spring.  Consider it mandatory for the repetitive stress reduction.  Air as soon as you lay your finger down, rather than a muscle-invocation, is a blessing, and makes “keeping the air on” all that much easier.