strange "spit"

[stormer]

I'm having some problems with my iwata revolution cr. When I pull the trigger the paint starts flowing fine, when I start releasing the trigger the line gets thinner as it should, but when I completely release the trigger (air still on of course) I get a final "spit of death" which means I get a thinner and thinner line until I get a "blob" that ruins everything. I have tried cleaning each and every part but nothing seems to help!

I don't know if the problem I had today comes from the same source, but I practiced a bit with my createx paint (real beginner with those!) and at one time I noticed I got bubbles in the cup when only having air on. The createx is thick and especially the pearly ones (really have problems getting them to flow) so the bubbles in the cup might have been just a buildup of paint problem and not be connected to the "spit of death" problem.

What part should I check to find the root of this problem?

Thanks!
Niclas

[fontgeek]

What kind of paint are you using when this happens?

Have you doctored/polished/sanded the needle?

I would check the needle first, if you have doctored it, then you may have changed how it seats in the nozzle, and that may leave an odd gap that collects that little bit of paint.
Check the needle to make sure it is straight and smooth, check the nozzle too.
If your paint is not well mixed or strained, then it may be that when you push the trigger forward, small solids are being forced out the nozzle and nozzle cap that otherwise rattled around in the nozzle or paint passage. Some paints are more prone to this problem than others.

If you have doctored your needle, you might consider replacing it with a new one. Make sure the needle cap, the nozzle cap, and the nozzle are clean and clear of any paint or debris. This may require a strong magnifying glass or jewelers loupe for the nozzle.
ALWAYS work over a contained area, like a roasting pan or something of that nature, that will keep you from losing piece if and when they drop.

Bubbling in your cup means that your airbrush found it easier to pass the air back through the nozzle and paint passage than it was to have it go out through the nozzle cap. If you are going to remove your nozzle to inspect it, then apply some beeswax to the threads before you reinstall it. Be careful not to over tighten the nozzle, they snap off easily. Check the nozzle cap and the needle cap to make sure that they are clean and clear of any paint or buildup of debris. If your Createx was really thick, then your airbrush may have found that it was too thick to atomize through the nozzle cap, so it forced the air back through the threads on your nozzle, if your needle was all the way forward, then it should have been sealing off the nozzle opening itself. Again, if you have doctored your needle, then you may have changed how it seats and performs.

[stormer]

I use mostly com-art because it's so easy to use, but also some createx (that I have a hard time with) and some schmincke effect paint that is very thick and contains lots of big pigments. I shake my paints VERY hard, but haven't thinned or strained the schmincke or createx since I'm afraid that'll remove lots of the effect pigments (pearls/mettallics), maybe that's why I can't get them to flow good and maybe also the reason for buildup somewhere?

My needle isn't manipulated in any way, but I could try to change it since I have a spare. I have to find a magnifier and inspect both the needle and the nozzle cap, it starts to sound like there might be some old junk in the cap!


Niclas

[brushbyair]

Stormer, first question you have to answer is are you having this problem withh all of your paints or only the thicker paints? From what you have said, I believe that it is a paint problem, try thinning the createx 1:1 with water, see if that helps, I have to massage almost all of my Createx paints when using my BH or my Infinity.

[fontgeek]

The pearls and metalics are touchier, but you will need to thin them or use an airbrush with a larger nozzle, and maybe more air pressure.
Each paint will be different in ratios of reducer/thinner to paint, even within one brand or type of paint. Createx has mucked about with the forumulas for their paints over that last several years, so some is really thick, some is already watery. For most airbrushes, the ideal viscosity for the paint is about the same as skim milk for the finished product. You may find that using Golden Transparent Reducer will help you out, it will let you reduce your paint without losing the adhesive quality. The metalic and pearl pigments may still be a bit of a problem, to get the effects of those paints, they need a fairly decent coverage, so while you may be able to reduce them so that they can spray, you may have to make several passes with the airbrush to get the desired effects.
As Brushbyair has pointed out, if you are only having the problem with the thicker paints, then that helps narrow down the cause. You may find that using coffee stirs to make sure you have the paint well mixed will help. Mixing and reducing the paint in a separate container from the brush itself will help too. I grab the little cups with lids from the fast food places I like, they give me good mixing containers that can last a good while without spending my money on expensive cups. They can be washed and used again and again.
Good luck!

[stormer]

I have had the same problem with all brands of paint I have tried, more of course with thick ones. I did try my spare needle today and suddenly everything worked so I guess I have something wrong with the other needle even if I haven't manipulated it in any way. Need to put it under the magnifying glass!

The createx paint I use is VERY thick, especially the opaque and pearl ones but with the pressure high it does flow now without the strange spit.

Thank you for the help!

Niclas

[pitontheprowl]

When using my AutoAir, I always reduce exept with the transparents(since most are really thin to start with).
I use the 4010 most of the time and if I need it to flash faster, then I use a hairdryer.

4010 Flash Reducer - Medium Dry
Use to thin colors for improved flow, leveling and spray-ability with a slight acceleration in drying time. For airbrush usage, 4010 Flash Reducer aids with control and preventing over-spray when using smaller tip sizes at lower PSI settings for cleaner lines for detailed work.

AB 401004: Auto Air Medium Dry Flash Reducer, 4 oz. $5.63
AB 401016: Auto Air Medium Dry Flash Reducer, 16 oz. $21.38
AB 401032: Auto Air Medium Dry Flash Reducer, 32 oz. $40.59
AB 4010128: Auto Air Medium Dry Flash Reducer, Gal. $150.21

4011 Flash Reducer - Fast Dry [top] Use to thin colors for improved flow, leveling and spray-ability with an acceleration in drying time. For airbrush usage, 4011 Flash Reducer aids with control and preventing over-spray when using smaller tip sizes at lower PSI settings for cleaner lines for detailed work.

AB 401104: Auto Air Fast Dry Flash Reducer, 4 oz. $5.63
AB 401116: Auto Air Fast Dry Flash Reducer, 16 oz. $21.38
AB 401132: Auto Air Fast Dry Flash Reducer, 32 oz. $40.59
AB 4011128: Auto Air Fast Dry Flash Reducer, Gal. $150.21
This is from Dixie's site
http://www.dixieart.com/Auto_Air_Bas...Extenders.html


Though, with the reducer I have had more tip dry problems so I dip my needle in retarder to slow the tip dry down a bit.

[atomizer]

apparently your not the 1st person to have this problem must be an iwata factory fault as mentioned above the needle isnt sitting correctly in the tip which leaves a gap and causes paint to build up untill.... SPLAT

i found a fix for it give it a go before you buy a new needle and tip

[oats]

Are there particular colors you are having problems with. This is the last Airbrush you should be having problems spraying createx with. It's a
0.5mm Airbrush and alot more forgiving with thicker paint. However sometimes createx is a little too thick. Usually diluting it to the consistancy of milk is a good starting point. Also depending on the age it's never a bad thing to strain your paint. It makes an amazing difference when there are no blobs. Pretty much only 2 things will give you bubbles in the cup besides a crack in the nozzle or somewhere else.
1- The nozzle cap is loose. Sometimes a litle beeswax on the threads helps this.
2-You have a blob particle in the nozzle itself which will create the same effect as holding your finger over the front of the brush and blocking the air from coming out-this will cause the paint in the cup to bubble and not pass through the nozzle.
Also what are you painting-If tee's I usually don't shoot below 40psi and mix the paint alittle thicker.

Paper or canvas the consistancy of milk and about 20psi is a good start.
That Revolution is nothing to snear at-My pics of the Stable were done 80 percent with it.
Hope this helps. Good luck!
Almost forgot-DO NOT mix paint in those little PAPER 3oz bathroom cups. The paper seperates and clogs the nozzle-Look for the little 3oz plastic ones.

[stormer]

Thank you guys. I got it fixed some time ago by doing a VERY VERY VERY good cleaning of the gun. I always clean the ABs good, but the nozzle can be tricky if you have something stuck there (which I had). The createx I use is a bit old (bought the bottles from a friend who never got around to use them) so they need that extra hard shake and some of them need to be diluted and strained.

And no, nothing wrong with the Revolution. I have three ABs now, the revolution cr, a hp-bc and a grex xn and I think I use the revolution most still because the ease of use when you want to just use couple drops of paint and don't have to worry THAT much about the consistancy of the paint. Of course, the hp-bc and grex xn both feel much better, the trigger is so smooth and all, but for the hp-bc you need more than the drops of paint and for the grex I have to be very careful what I put in it or it will clog almost before I pull the trigger

Niclas