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Stewarts Systems Fish Eyes

TroyBranch

Well Known Member
Friend
I know there is a lot of smart people on here and I need some help. I have painted my last airplane with SS and had no trouble. I love the paint. It worked perfectly. Now I am using it again and for some reason my Yellow gets a random fish eye. If I look really close the paint almost falls in places like the beginning of a fish eye. Like something is going wrong as it cures. They start to form around 5 minutes after shooting. I have been trying to solve this with the Stewarts factory for 2 months now. :eek:

When it happened I upgraded my filter system by adding a desiccant and a charcoal filter. Basically to eliminate the chance of water contamination. This is the system, as you can see air filtration should be covered.

kbqan8.jpg


I also changed my hoses from what I was painting with last time even though there was never an issue then. No change.

I then added a 50ft copper pipe coiled in a barrel of water to cool the air before it goes into the tank. Eliminates the chance of warm air at the gun which could condense at the tip and form water. Cold air filters better as well. Still no change.

This is the example. Around one every square foot.

55ibtv.jpg


I decided to shoot the black and got a perfect paint job. I have since painted all my black parts with no issues at all. So I sent the yellow paint to Stewarts. The Canadian distributor got a bit of the issue at a lesser scale when testing and the main branch cannot reproduce it all. They say the paint is fine.

So the last thing I tried was removing the paint filters on the intake side of the booth to see if that was it. (They are the proper sticky back filters) No change.

After keeping this quiet since mid November I really need to reach out to everyone for ideas. The factory cannot figure out what is causing it. I have red coming to me now to test which I shot on the last plane with no issues. I really hope that works. Then I just need to re shoot a few parts changing them to yellow. But why is the yellow doing this?

All testing was done on bar aluminum cleaned with thinner to rule out surface contamination. I live in the country not near a railway and have nothing silicone based in the garage. My gut feel is that maybe there is still some contamination in the air supply but I cannot figure out how. Yellow has the least amount of solids so maybe the slight contamination is only effecting it?

My compressor is a 60gal and at the bottom of the chart for what I should have. 11.5cfm at 90psi. It keeps up fine and worked just fine on the last paint job.

Can you think of something that I may have not tried?
 
Fish Eye Eliminator

Not a professional painter here, but I know they make this stuff for a reason.

Thinking it is generic but you might see if SS has it for their product line.
 
If you have eliminated the possible surface contamination, then it is in the supply system. I assume you have a final filter at the gun too. I can not read the filter spec on the SATA final system filter, but suggest using as fine as you can get there. 0.1 micron if possible.

The last possibility is coming from something downstream of the final system filter. There are several fittings, regulator and valves there. I don't know the tolerance for such things but the factory should. Hopefully they are concerned about more than if their paint is good. They should be able to tell you the cleanliness specifications for their product, and how it is measured for production operations quality control. Maybe they take the gun and spray it into a sealed container with an absolute filter that is analyzed in a lab.
 
If the black comes out fine then there's a problem with Stewart's yellow. Have you tried another batch from them?
 
If you have eliminated the possible surface contamination, then it is in the supply system. I assume you have a final filter at the gun too. I can not read the filter spec on the SATA final system filter, but suggest using as fine as you can get there. 0.1 micron if possible.

The last possibility is coming from something downstream of the final system filter. There are several fittings, regulator and valves there. I don't know the tolerance for such things but the factory should. Hopefully they are concerned about more than if their paint is good. They should be able to tell you the cleanliness specifications for their product, and how it is measured for production operations quality control. Maybe they take the gun and spray it into a sealed container with an absolute filter that is analyzed in a lab.

The final Sata Filter is charcoal.
The devilbiss is (Second filter)
Centrifugal Filtering Capacity: 5 micron

Coalescer Filtering Capacity: .01 micron

All fitting are specific to the filters other than the coupler.





If the black comes out fine then there's a problem with Stewart's yellow. Have you tried another batch from them?

Same issue with two different lots of yellow.
 
Ahhh - - both charcoal and desiccant can release particles, so, I was thinking the last filter was particle only. The desiccant and charcoal will adsorb gasses and capture aerosols. I would check with the company, but I would have thought the finest filter would be the last one, and it would be a particle filter.

You might want to call these guys and ask, they are experts on filtration.
http://www.driair.com/contact/
 
Troy - I feel your pain. Not with fisheyes in a topcoat, but with SS epoxy primer. I could not get the stuff to work for me.
A phone call to Dan at Stewart and I learned the challenges I was having were not unheard-of. I didn't have to ask; he immediately offered to replace what he assessed to be defective product.

The new product went on beautifully, but not before I had spent hours and hours sanding off the defective stuff.

Nobody's perfect. Dan certainly did his best to make amends.

Question for you... Which SS paint are you using? How do you like the final gloss of the finish? I may be purchasing our topcoat in the spring in order to have it on hand for application once the weather warms up.
 
Question for you... Which SS paint are you using? How do you like the final gloss of the finish? I may be purchasing our topcoat in the spring in order to have it on hand for application once the weather warms up.

Ecopoly top Coat. Great shine and almost no smell. It is very forgiving...just don't by yellow.:rolleyes:
 
I had the same thing happen when painting small parts and, for me, it was in the gun itself. I washed it with acetone, then Dawn, then 91% rubbing alcohol.

Finally, I got a good application on my parts. I don't know where the contamination came form since the gun worked well in the past.
 
SS Paint System

I am really interested in the outcome/resolution of this SS problem. Please keep us all informed when you resolve e the problem.

Two months is way too long without resolution - suggest that you try talking to the US factory. I am considering SS and the resolution of your problem may be the deciding factor on Y/N.

Please keep us advised.
 
Fixing Fish-Eyes

I'm currently painting also and here is what I've learned about fish eyes.
Somewhere contamination is getting on your part.

1) So are you using a de-waxer & de-greaser? And using it liberally. I mean spray it on soaking wet out of a spray bottle then wipie it off with new clean clothes, before painting? Just using a damp towel is not good enough.

2) One way I fixed a few fish-eyes, is that after the first coat you can see where a fish-eye is forming. This is during the flash time, while I'm waiting to spray the second coat. Take a small (very small) paint brush and put a dab of paint on the fish-eye. Touch it right in the hole. You might even move the brush around a little to mix up the dab with surrounding paint. Yes this makes a mark on the first coat. But it seems to get rid of what ever is contaminating that spot. And the second coat covers it up and you never see it again. Just be delicate with touching up the fish-eye.

PS, I have also dabbed paint on a fish-eye the next day, after the paint has "dried". After a few more days, you can't see it. Seems like paint doesn't really dry overnight, but dries and sets over time, so a little dab gets absorbed if done right away.
 
I'm currently painting also and here is what I've learned about fish eyes.
Somewhere contamination is getting on your part.

1) So are you using a de-waxer & de-greaser? And using it liberally. I mean spray it on soaking wet out of a spray bottle then wipie it off with new clean clothes, before painting? Just using a damp towel is not good enough.

On the test panels I used wax and grease remover, thinner and alochol to clean it. All the same results. On primer the only item is 91% alcohol lightly sprayed on a high quality low lint new towel and wiped down prior to top coat. If the primer is new this step is not a have to but recommended. The prime coat sprayed fine and I get the same results on bare aluminum and primer with the top coat.
 
I had the same thing happen when painting small parts and, for me, it was in the gun itself. I washed it with acetone, then Dawn, then 91% rubbing alcohol.

Finally, I got a good application on my parts. I don't know where the contamination came form since the gun worked well in the past.

I clean the gun with water then lacquer thinner each time. I am using at Sata 4000B gun and disposable cups. Your method is worth a try. Not sure where the contaminant can be in the gun. Was this with a SS product?
 
I haven't painted my rv-12 yet but tried some smaller test pieces. I had some fish eyes that I traced to mixing the paint. I was using a small siringes to get the correct paint volume. These apparently has silicone in them. I used non-silicone ones from a medical supple place and the issue went away. Could it be something in your mixing?
 
I haven't painted my rv-12 yet but tried some smaller test pieces. I had some fish eyes that I traced to mixing the paint. I was using a small siringes to get the correct paint volume. These apparently has silicone in them. I used non-silicone ones from a medical supple place and the issue went away. Could it be something in your mixing?

I am mixing in the disposable Sata cups. All new stir sticks. Same process as I did on the first plane with no issues.
 
Fish Eyes or Solvent Pop?

Hi Troy,

Just wondering aloud here... I too am using SS. I changed from Insignia Blue to Insignia White as I struggled to get an acceptable finish with the Blue.

One of the issues I had was with solvent pop. Could that be what you have, or is it fish eyes? I sanded back countless pieces before resolving my issue. Too heavy a final coat, usually laid on horizontal surfaces.

Best wishes,

RBR
 
Hi Troy,

Just wondering aloud here... I too am using SS. I changed from Insignia Blue to Insignia White as I struggled to get an acceptable finish with the Blue.

One of the issues I had was with solvent pop. Could that be what you have, or is it fish eyes? I sanded back countless pieces before resolving my issue. Too heavy a final coat, usually laid on horizontal surfaces.

Best wishes,

RBR

Solvent pop usually boils out. There is many area that the finish sinks, like it is starting a fish eye but is not deep. All my surfaces are vertical where if I had to much paint it would at least sag. I got the gun setting nailed for the finish I want. You need enough to flow but not run. I sprayed 4 gallons of this stuff on the last plane with not a single issue. Fire horn red, drab tan and black. Black is working and I should get the red this week. If it works, I am changing the color.
 
Fish Eyes

There are several things that will cause this. Oil in your air line, Armoral in the air and using a new tack rag before appling paint. Always use a "used" tack rag on final surfaces if you must.
If you are using a new air line and or a used one that has been attached to a sander, drill etc. run some thinner through it and blow it out till dry.
 
There are several things that will cause this. Oil in your air line, Armoral in the air and using a new tack rag before appling paint. Always use a "used" tack rag on final surfaces if you must.
If you are using a new air line and or a used one that has been attached to a sander, drill etc. run some thinner through it and blow it out till dry.

I use tack rags designed for the water borne paint. When it first happened I put every Armorol container in the house. Bought a new hose, went to half inch hose from the compressor to the filters and a shorter 25ft, 3/8 line to the gun. I flushed that line with wax and grease remover to make sure it was clean before I used it. Checked the exit air with a mirror to confirm dry clean air.

I really appreciate all this feed back, if any thing it will be a source of good info for everyone:D
 
Wax and grease remover

Wax and grease remover will cause fish eyes if you use it over your primer and or flush lines with it.
 
Wax and grease remover will cause fish eyes if you use it over your primer and or flush lines with it.

This is interesting, I flushed my line with it based on info from a friend that is in the painting business. They do this as part of their maintenance program on the system several times a year. I will buy a brand new line again, cheap test.
 
I just received the test sample that SS sent with the red paint that I will test. Their test sample had the same issue I am having. They missed it. I am quite confident my system was always good. I am going to spray the red tonight and see what happens. They are now going to figure out what is creating the issue with the yellow. I will not wait for that outcome, if the red works, I will spray red and re prime the painted parts to change the color. I am sure that fixing the yellow will take some time.
 
I shot the red last night and it is perfect. They have narrowed it down to trouble with the tint. It happened to another color with the same tint. All my planes have had red, I guess a change in color was never meant to be.

Thanks to everyone for the comments. I am just glad to be able to finally paint a color that is going to work. I have a bunch of sanding and re priming on a few parts but at least I have a direction to head.
 
Troy,
You're using EkoPoly, right? What are you using as a primer (if anything) before application? What's your prep process? I'm still a couple years out from doing the exterior paint, but I'm probably going to wind up doing it myself. This system sounds attractive because it doesn't seem quite as nasty as some of the traditional paints.
Thanks
 
Troy,
You're using EkoPoly, right? What are you using as a primer (if anything) before application? What's your prep process? I'm still a couple years out from doing the exterior paint, but I'm probably going to wind up doing it myself. This system sounds attractive because it doesn't seem quite as nasty as some of the traditional paints.
Thanks

You wash the aluminum with their eco clean, the spray it with eco etch and scrub it with scotch brite, keeping it wet. Rinse with a wet terry towel and then spray wash clean with water. After it is dry you shoot on the eco prime. Next is a light scuff with scotch brite, wipe with a light spray of 91% alcohol on a low lint towel then tack rag. Shoot the color and done. Very little smell and a safe easy process.
 
Troy - I appreciate you taking the time to share your technique and other info here. I was going to use EKo-Crylic, but you've now got me interested in the EkoPoly as it seems to be a more flexible finish. Thanks for opening my eyes to this possibility.

Which red have you chosen to go with? I'm thinking Pontiac Red for our project. Wish I could get some LARGE colour samples to allow a more informed colour choice. I have a "larger" sample of the Pontiac Red, but it's still pretty darned small compared to the size of the airplane... :)
 
I am using fire horn red. It is brighter to the red on my Rv 10 and also shinier. I will pm you a pick of it on the last plane I built.
 
Thanks, Troy - much appreciated!

If it's easier to send the pic via email, the following address works:
cgjoy (at) yahoo.ca
 
I would like to suggest that any new can of paint, you should spray a test sample. Never assume the can is good. I got the new gallons of red and sprayed my flaps a couple of weeks ago. Same problem with red now, flaps need to be stripped. I have tested and tested narrowing it down to can contamination. I shot it in a professional booth yesterday to rule out my system. It shot the same way in a professional booth. Save your self some trouble and always test spray any new can. I just have no trust in the consistency of the paint now. Still waiting on Stewarts to test the red from a gallon can to see if they get the same results. This is my fifth airplane build and if every project went like this, I would have stopped at one!:D
 
Are you using a syringe to measure your paint? I did and I got more fish eyes than a trout farm. I studied up and found out silicone is used to lube the plunger of some (maybe all) syringes. No syringe...no fish eyes.
-Nathan-
 
Are you using a syringe to measure your paint? I did and I got more fish eyes than a trout farm. I studied up and found out silicone is used to lube the plunger of some (maybe all) syringes. No syringe...no fish eyes.
-Nathan-

Nope, they told me that story. LOL. All mixed with new Sata cups and new stir sticks.
 
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