jimboflying
MEMBER
paint question
- Thread starter jimboflying
- Start date
bob turner
Registered User
I wish they would certify a more standard topcoat. I love their glue and Ekofill, and find that it is a good base for butyrate. We re-taped a fuselage, then another shop sprayed a urethane top coat over our extensive Stewarts repairs. Gorgeous! It sat outside for over three years - many parts of the aircraft, including factory new wings, suffered greatly, but that fuselage still sparkles with no cracks.
My personality has a difficult time with very precise measuring of fluids - it is all I can do to set a carburetor up. When I spray paint it is a little thinner here, some rejuvenator there, some retarder maybe, all splashed into the gun, and zap. Stewarts finish will not put up with that.
My personality has a difficult time with very precise measuring of fluids - it is all I can do to set a carburetor up. When I spray paint it is a little thinner here, some rejuvenator there, some retarder maybe, all splashed into the gun, and zap. Stewarts finish will not put up with that.
Bearhawk Builder
FRIEND
In the woods
Hard telling from the picture but I've seen ekoprime do something like that if you put too much on too fast. Should sand out easily though.
It's hard for me to see from your picture, but I think I am seeing solvent popping. You may have applied a too heavy top coat over a not sufficiently tacked and maybe too thick lower coat. I fog coat until i get the color the way I want it, then I apply the last coat with the same gun settings, only closer and slower with the gun.
Bearhawk Builder
FRIEND
In the woods
Is it ekoprime or topcoat?
skysigns
FRIEND
Yelm WA 98597
you tried to spray it to heavy you need to do a light fog coat first and make sure to use a good water trap
jimboflying
MEMBER
It is ecoprime which was diluted with water 10%.
G44
MEMBER
SW Michigan
Ok, well, there goes my theory then...
Marty57
PATRON
Nipomo, Ca
A few hints for the EkoPrime. Regarding thinning it out, using a viscosity cup is a good way to ensure that the material is properly thinned. Viscosity in the 22 second range works well. Ekoprime is ready to be sprayed right out of the can but, if necessary, can be thinned with distilled water. No more than 10% water is recommended. Sounds like you thinned it ok unless it already had been thinned. Runs like that can come from a combination of issues or any one of the following: gun tip size, pressure at gun, and speed of application and distance from surface. With the Stewart Systems finishes, light fog coats are recommend even when using Ekoprime or Ekofill to build up surface thickness. I'm teaching the seminars for Stewart Systems and if you can give me some more info on your set up I can help figure out what caused the runs. As stated above, Ekoprime will easily sand out with 320-400 grit open coat paper (dry sanded) after just a few hours if temps are in the 60-70 degree range.
Marty
Marty
jimboflying
MEMBER
Thanks for the many ideas. The setup used was a Rotary air compressor with lots of air available, Refrigerant air dyer, 50 psi at separator pressure regulator, 50 feet of 3/8 air hose with 2 wide orifice couplers, 25 psi at gun gauge available but set to 18psi, Binks M1-g HVLP gun, 1.4 mm nozzle, 1 light fog coat followed by a heavy wet coat as per instructions, temp of spray booth was 72-76 F. , spray distance about 7 inches.
Since I was doing 2 wings, could the fog coat have dried too much before I got to the heavier wet coat and the thinner paint ran off?
Since I was doing 2 wings, could the fog coat have dried too much before I got to the heavier wet coat and the thinner paint ran off?
bob turner
Registered User
The reason for the ekoprime is to make it easier to shoot yellow. If your top coat is white, you probably do not need primer. I have never had adhesion problems over Ekofill.
Marty57
PATRON
Nipomo, Ca
That wing looks very nice; you have the EkoPoly application down. As far as shooting urethane over Ekoflii; why dosen't the customer want Ekopoly over the Ekofill? I gather the wing you are shooting now is also exp? Urethane over Ekofill isn't in the STC because those finishes were not tested together so not legal on a certified bird. A catalyzed urethane should work fine but when you start mixing different types of paint with different thinners (solvents vs distilled water) you definitely cross over into the experimental zone. Depending on the urethane, adhesion is somewhat of an unknown. Ekopoly and Ekofill are designed to be fully compatible so I would recommend to the customer to stick with the same system. If they want a clear coat that is available in Ekopoly. From the perspective of your warranty on the urethane top coat, if the urethane isn't comparable and issues crop up in a year or two what happens?
Marty
Marty57
PATRON
Nipomo, Ca
Bob,
Agreed, yellow over Ekofill is hard to get color saturation without putting on more paint than needed. White or charcoal gray Ekoprime is very helpful for achieving full color saturation. Orange is another color where white Ekoprime over Ekofill is desired.
Marty
Hardtailjohn
Registered User
Marion, MT
I'd like to see a bigger, better picture of that problem. I can't see much detail from a small picture like you have. I've been using this system since the 90's and have gone through the changes from what it was back then. From what I can see from this picture, I'd be more apt to call out a contamination, especially if you have good results elsewhere on that surface.
John
John
Bearhawk Builder
FRIEND
In the woods
Hardtailjohn
Registered User
Marion, MT
EkoPoly premium is still a polyurethane.
Marty57
PATRON
Nipomo, Ca
Marty57
PATRON
Nipomo, Ca
I shot some White Ekoprime on previously sprayed and sanded Ekofill for a seminar I'm teaching this weekend. Thought I'd share settings and results. I'll be shooting Metallic Yellow EkoPrime on both these surfaces.
Surface prep: Clean with 91% Isopropyl Alcohol on damp synthetic shop towel followed by waterborn paint tack cloth and last wipe with lightly alcohol dusted cloth.
Gun: DeVilbiss Finishline 4
Tip: 1.5mm
Pressure: 58-60psi feed at regulator; 23psi at gun. Air is 13cfm and dry,
through a dryer set up with three different traps. 3/8" fittings with only quick disconnect is gun.
Gun Settings: Fan open wide; volume 3/4 turn open
EkoPrime: Checked from can at 25 seconds viscosity; thinned with a little water in gun. 25 seconds will give a dryer spray that will dry quickly in cool temps. 21 seconds will give smother finish. 25 seconds gives slightly rough finish ready for 400 open coat in less than one hour.
Application: Medium fog coat; applied 2-3 light cross coats. Purpose of Ekoprime is to lighten up surface for easier color saturation with yellow EkoPoly to follow. This set up will achieve the lightest in weight finish with minimal top coat to achieve proper color saturation.
Ready to lightly sand with 400 open coat in about one hour.
Hope this helps figuring out the application of EkoPrime.
Marty
Surface prep: Clean with 91% Isopropyl Alcohol on damp synthetic shop towel followed by waterborn paint tack cloth and last wipe with lightly alcohol dusted cloth.
Gun: DeVilbiss Finishline 4
Tip: 1.5mm
Pressure: 58-60psi feed at regulator; 23psi at gun. Air is 13cfm and dry,
through a dryer set up with three different traps. 3/8" fittings with only quick disconnect is gun.
Gun Settings: Fan open wide; volume 3/4 turn open
EkoPrime: Checked from can at 25 seconds viscosity; thinned with a little water in gun. 25 seconds will give a dryer spray that will dry quickly in cool temps. 21 seconds will give smother finish. 25 seconds gives slightly rough finish ready for 400 open coat in less than one hour.
Application: Medium fog coat; applied 2-3 light cross coats. Purpose of Ekoprime is to lighten up surface for easier color saturation with yellow EkoPoly to follow. This set up will achieve the lightest in weight finish with minimal top coat to achieve proper color saturation.
Ready to lightly sand with 400 open coat in about one hour.
Hope this helps figuring out the application of EkoPrime.
Marty
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jimboflying
MEMBER
Different paint question this time. My horizontal stabilizers were covered using the Polyfiber technique with Polytone as the topcoat. Cracks in the finish have occurred just behind the leading edge tube. My question is how to fix it?
supercrow
FRIEND
Smith Pond near Millinocket, Me
My first question is how many cracks do you have, and how old is the finish. Polytone is easy to repair as it will soften easily with solvent and you can practically swipe them out and refinish. You will see repairs unless you carefully sand and then recoat the entire piece. Polyfiber colors are the same basic material as the silver coats under them with color added, so be careful not to go to far and lose your UV protection for that area. If you do apply silver and then color again. If you plan to fly that fabric for years to come, you might want to consider repairing the cracks and then apply a coat of aerothane to get some flexibility in the top coat. If you are worried about the new coats being too shiny just dull the finish coat with a little more thinner or add some flattener that is made for aerothane. If I haven't answered your question, feel free to ask some more. What you have there is a pretty easy fix at any rate and will hold up when repaired unless the fabric was not shrunk enough when installed and that is what caused the cracking because of excessive flexing.
jimboflying
MEMBER
The fabric and Polytone is about 10 years old. The cracking is only right next to the trailing side of the leading edge tube of the horizontal stabilizer. Would MEK be the correct solvent?
supercrow
FRIEND
Smith Pond near Millinocket, Me
Yes, that will work, though lacquer thinner will work well do. I use more of the lacquer thinner because it is cheaper by the 5 gallon pail. If what you have going on there is only in the last year or two I would say you had no fabric install issues. If only two or three years old, I would be more concerned. Those kind of issues you have are not uncommon at 10yrs.
duckhunter10
Registered User
Mine has gotten stained with bird poop and other stuff over the years and someone suggested painting it. Fabric is ceconite and in good shape, plane has never been outside in the sun. I once had a 12 that had been repainted and it didn't hold up too well.
jimboflying
MEMBER
Sprayed the infamous Yellow top coat. Side one went fine but side two is still tacky after two days. Ideas?
Sent from my iPhone using SuperCub.Org mobile app
Sent from my iPhone using SuperCub.Org mobile app
Attachments
jimboflying
MEMBER
One side at a time. Different batches from same cans.
What top coat are you using? It sounds like not enough catalyst in what ever process you are using. I'm into my third project with Stewart's and have had a few minor problems, if that is what you are using. I like it and can spray right next to my hangar furnace and not worry about blowing up.
