Problem with my Iwata HP-C Plus

Chris,

Being faithful to always buying brand compatible products, I ordered the Medea-Iwata Super Lube through the LHS (Hobbytown USA).  Like I said in the beginning, though, it was right after the first time I used the stuff that I first had the sticky trigger problem.  When I say right away, I mean within two painting sessions.  As I did nothing different (except for using the Lube), it naturally caught my attention.  For a  year or more before that, the AB had performed flawlessly without the use of any lube at all by me.  I Just can't help but connect the dots.  According to everything I've read and learned, however, those two things shouldn't be connected, but my gut still tells me they are.  Things are back to flawless (AB only) but I still don't fully understand what went wrong in the first place, so I'm crossing my fingers.

TomB

Well I can see you got your problem solved. i have an HP also.  I had the same problem, but it didn't occur until after a year of use.

It might have been the Testors acryl paints. they really seem hard to clean out. The model master enamels are great. I think I'm going to switch to polyscale on the acryls.

But, I cleaned mine out blasting the trigger assembly with CRC electronic parts cleaner since it doesn't harm the o ring. Then I used the lubricant from Coast AirBrush.. 

https://www.coastairbrush.com/products.asp?cat=319

Seems to work for me ok..........

Good to hear it helped.  It helped me for a while as well but I think I need to find some airbrush lube.  I cannot for the life of me find any at my local hobby shops but I think I need to get some soon.  My trigger is still a bit sticky at times.

 Chris

CNicoll wrote:

I heard back from Iawata and the information got my airbrush working like new in about 20 minutes.  Thanks to Adam Rice at Iawata.  He responded within hours and was spot on with his directions.  Good guy!

Thanks for all your info.  I finally got my AB back to working correctly, but I ended up having to replace the O-ring that the trigger piston slips through (twice).  Adam at Iwata helped me through it, but it was a little frustrating.  After ordering and finally receiving the parts, I followed the same procedure both times--- 1) somehow insert the pesky little O-ring, 2) put a tiny amount of lube on the piston and contact surface of the O-ring, and then 3) insert the piston.  One time the fit was a hair too snug and the stickyness problem remained after assembly and hookup.  The second time, the fit was just a hair looser and the trigger release is back to normal.  Seems like a very small tolerance, and I'm crossing my fingers that it holds for awhile, since I don't really know what I did different between the two replacements.  I do think the O-rings themselves may not be precisely identical (one worked and the other didn't).  Anyway, thanks to both of you for helping me do the repair myself.  Having been forced to tear everything down several times and replace a few parts, I now feel that I have at least a chance of fixing pretty much everything on the AB myself if I have to.  That's cool.

TomB

CNicoll wrote:

This should solve the symptoms of your problem.  How-to Clean and Lube a High Performance Valve Piston  by Adam Rice Let me know if you run into any problems.  I'll be more than happy to help you out.

Chris,

Thanks for the feedback.  I followed the instructions, but still have the problem.  Except for the exact amount and placement of the Lube, I'd gone through this procedure before several times.  Everything works fine through the initial testing and assembly (no problem with springback), but when I attach the air supply the sluggishness returns, worse at lower pressures, better as pressure increases.  I've broken down, cleaned as described, and reassembled with and without the Lube and the problem remains.  My next candidate is the packing air piston (O-ring), but I'm not completely sure from the diagram which part that is.  Theres a rubber ring-type washer at the base of the treaded portion at the upper end of the air valve body, but there also appears to be a black rubber washer of some kind that the valve piston passes through before it contacts the air valve.  It's only visible from the botton side of the AB and looks to be a fully integrated component, meaning that it looks to be sandwiched between two metal parts and I can't figure how it could be removed or replaced, like E suggested.  It seems like the most likely contact point where the stickiness might occur, however.  I'm going to try contacting Adam at Iwata.  Did he have a specific contact address?  Thanks again.

TomB  

Part 2 of my earlier message:  BTW, it really helps to have the parts diagram nearby.

Short-term Solution:

 This should solve the symptoms of your problem.

 How-to Clean and Lube a High Performance Valve Piston

 by Adam Rice

 Refer to the appropriate parts guide, which can be found at

 http://www.iwata-airbrush.com/support/specs.jsp

 Equipment

     * Towel or Tray to work over

     * Needle Nose Pliers or Tweezers

     * Cotton Swabs

     * Cleaning Solvent

           o Laquer Thinner

           o Acetone

           o Alcohol

 Disassembly

    1. Unscrew the Handle

    2. Unscrew the Needle Chucking Nut

    3. Pull out the Needle

    4. Unscrew the Spring Guide

    5. Remove the Needle Spring

    6. Remove the Needle Chucking Guide

    7. Pull the Main Lever up and out

    8. Turn the Airbrush Body over your hand and jiggle out the Auxilliary Lever

    9. Use the Needle Nose Pliers to pull out the Air Valve Piston

 Cleaning and Lubing

    1. Use a Cotton Swab to clean off the Valve Piston

    2. Remove some of the cotton fibers from a Cotton Swab and clean the hole at the bottom of the Trigger Housing

           * Clean until a Cotton Swab comes back clean

    3. Place a very small drop of Super Lube on the shaft of the Valve Piston

    4. Place the Valve Piston back into the hole at the bottom of the Trigger Housing

    5. Place the Main Lever back into the Trigger Housing

 Testing

• 1. Press up and down on the Main Lever a few times, it should feel nice and smooth and spring back up when depressed

 Reassembly

1. Place the Auxilliary Lever back into the Trigger Housing behind the Main Lever

          1. Check the Parts Guide for the proper orientation of the Auxilliary Lever

          2. Grab the small tab on the Auxilliary Lever from the side

          3. Insert the Auxilliary Lever sideways into the Trigger Housing

          4. Twist the Auxilliary Lever into the proper orientation

          5. Hint: You ight want to hold the Airbrush Body with the front dipped down slightly to let gravity help instead of fight your efforts

    2. Place the Needle Chucking Guide into the Airbrush Body

    3. Place the Needle Spring over the Needle Chucking Guide

    4. Screw the Spring Guide into the Airbrush Body

    5. Push down on the Main Lever at least once

    6. Carefully insert the Needle * Warning: This is the most probable time to bend the Needle point

    7. Screw the Needle Chucking Nut onto the Needle Chucking Guide

    8. Screw the Handle back into the Airbrush Body

 Let me know if you run into any problems.  I'll be more than happy to help you out.

I heard back from Iawata and the information got my airbrush working like new in about 20 minutes.  The message is a bit long, so I'll post it in two parts.  Here is the first one.  Thanks to Adam Rice at Iawata.  He responded within hours and was spot on with his directions.  Good guy!

 The sticky trigger issue is usually caused in one of three ways.

 1) You pull out the needle while you still have paint inside the airbrush. This draws paint into the trigger housing which in turn gums up the mechanism.

 2) You soak your airbrush in cleaning solution when you're done using it.  This removes the lube and, depeneding on the solution can make the o-ring in the air valve swell up.

 3) You're over cleaning your airbrush.  If you keep removing the lube from the air piston it will stick.  Generally you only need to keep the places where paint goes clean.

Long-term Solutions:

 1) Stop pulling out the needle while you're painting.  This should lengthen the time between lubes significantly.

 2) Stop soaking your airbrush to clean it.  If this is your problem, let me know and I'll send you some cleaning instructions.  If the o-ring has swelled up you might need to let the airbrush sit for a few days to let it off-gas and get back to it's normal size.

 3) Stop over cleaning the airbrush and only clean the places that need it. Again, I can send you some cleaning instructions.

MikeV wrote:

I would not use vegetable oil, pertroleum based oils or anything of that nature as there is a possibility of contaminating the paint.

Not only that, vegetable oils tend to gum up and "varnish" very quickly. One may as well pour glue into an airbrush - it will do the same thing, only faster.

Though less of a problem with modern synthetic rubbers, petroleum based oils can cause rubber O-rings and seals to swell, again causing a "sticky" action.

TB6088 wrote:

Of course, there is the outside possibility that some green-with-envy Badger fanatic has sabotaged the entire Super Lube supply in order to cut the competition down to (Badger) size. Sorry, I couldn't either. TomB

Iwata is no competition for Badger.

I have used both Badger's Regdab and Medea Super Lube for years with no problems at all but then again my bottle of Super Lube is 10 years old or so. 

I wonder if they changed it? I would not use vegetable oil, pertroleum based oils or anything of that nature as there is a possibility of contaminating the paint.  

i just received my first Iwata airbrush today....now I'm scared to use it...or clean it!!

mark

Hey TB, are you removing the air valve when you clean with lacquer thinner.  If not, the lacquer thinner is probably slowly disintegrating your air valve seal which is not lacquer friendly.  The problem is that if the needle is removed while the main brush is cleaned, a small amount of thinner can seep back throught the needle bearing, down the trigger housing into the air valve area.  Even with the best of care, it's hard to keep thinner out of the air valve when cleaning if it's not removed from the main body prior to cleaning or soaking.  You may end up replacing that seal to get a smooth trigger action again.

E

MikeV wrote:

Is there a design problem with that model? When I see two people with the same problem I wonder.

MikeV,

I don't think it's a design problem.  I've used the AB for a couple of years with nothing but perfect performance (the AB's, not mine), and now all of a sudden I have this problem.  My inclination is to look for any change in how I've been doing things, and like I said, the only change I can think of that occured shortly before the problem started was the fact that I started using the Iwata-Medea Super Lube.  I've always used alcohol and/or laquer thinner to clean after breakdown, and things were so squeaky clean that I though I'd try using a lubricant.  I thought about glycerine but decided to get the manufacturers product (a habit learned from paints).  Anyway, now I suspect it's all a plot by Iwata to get me to buy replacement parts, but I probably won't mention that particular sentiment to the guy at the website that E mentioned when I contact him.  Of course, there is the outside possibility that some green-with-envy Badger fanatic has sabotaged the entire Super Lube supply in order to cut the competition down to (Badger) size.

Sorry, I couldn't either.

TomB

An Iwata with a problem?

I thought they were the best out there?

Sorry. couldn't help myself.

Is there a design problem with that model?

When I see two people with the same problem I wonder.  

Go to the Iwata-Medea website and send an email to Adam Rice in tech support.  He should be able to help you guys out.  HTH!

E

I have the same airbrush, and am having the same problem with the trigger.  I thought perhaps I was not cleaning it properly, even though I thought I was being very thorough after every use.  I followed the detailed breakdown directions (as TomB appears to as well) but still have a trigger that is slow to release.

If anyone has any ideas, please let me (us) know.  I even posted a question to the vendor I bought the airbrush from and they said to use lube.  Not much help.

Thanks! 
Chris

H3nav wrote:

Did you use Super Lube?

E

It's funny you should mention the Iwata/Medea Super Lube-- I heard about it on the forum and got some a little while ago.  I noticed that my problem started shortly after using it for the first time. Initially I thought the SL might be gumming up the space between the pin below the trigger and the washer around it, or the piston below that, or ?... since I'd never had the problem before.  However, I've cleaned the AB since then without using the SL and I still have the problem, so I discounted the SL as the cause of the problem and assume the timing was just a coincidence.  Pretty strange, though....... 

TomB 

Did you use Super Lube or Regdab after you cleaned it?  If not, try that and post back.

E