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Cheaper clear coating found

Old 02-18-2007, 07:53 AM
  #26  
bps
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Default RE: Cheaper clear coating found

Great information here. We are all looking for better (read more performance at a better price) model products. I tested the Krylon as well and found it to be a great product for glow fuel. Wal-Mart has a private brand of clear spray that sells for a buck and does a great job as well. Only in gloss though. The clear acylic enamels will not stand up to gas though. So if you have a gas powered model or plan to put a gas motor on in the future you will need to recoat.

JEB
Old 02-19-2007, 10:45 AM
  #27  
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Default RE: Cheaper clear coating found

I just finished a spit fire. I sprayed the last color -camoflage green 1 week ago. This weekend I used the krylon Satin and just about cried. Mind you, I used all Krylon paints so there should have been no incapablity issues but the first thing I noticed was that the the clear dramatically changed the color.. especially on the gray. Then I painted the cowl and found out that it fogged over the green areas! It improved as it dried but two days later there is still a smokey apperance. I also had a problem with the grey areas in that when cured.. there were strange patterns developing at random.

By the way, the spray area was about 75 deg and the can was warmed in hot water just to get that out of the way.


Best regards,
Randy
Old 02-19-2007, 01:51 PM
  #28  
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Default RE: Cheaper clear coating found

That's a tough one. Clear can sometimes change the hue of the underlying color. Gloss clears tend to richen the color while satin or flat clears will wash it out a bit. Can you describe the "random patterns" a bit more. Foggier areas maybe? You may have just gotten a bad can of clear too. If you have any left, spray it on a piece of clean metal or the like. How does it react then? A word of advice on all satin clears - shake the can to within an inch of it's life. The flattening agent that is added to clear ( or color for that matter ) tends to settle out rather quickly. If the can has been on the store shelf for a while, the agent can become a rock in the bottom of the can. If it's not dispersed in the clear really well, varying degrees of sheen could result while using the can.

Regards,
Dan
Old 02-19-2007, 04:36 PM
  #29  
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Default RE: Cheaper clear coating found

I went back and read the entire thread and wanted to post a little about paint chemistry that may help everyone out there. This is what I do for a living and have found that once you understand a little background, the puzzle pieces start to fall together a little easier.

Paint can be broken down into basically two chemical categories - thermoplastic and theromset. Lacquer, acrylic or not is considered a thermoplastic. That means it can be broken down with either heat or solvent. The oily residue may discolor it a little bit but add heat to the equation and you have a recipe for it coming off. That's why raw fuel reacts slowly but hot exhaust products react poorly with a lacquer finish. Time isn't much of a factor when it comes to lacquer. Lean against someone's old lacquer finished Vette with fuel or solvent and you had better have your running shoes on. Acrylic is a plasticizer that is added to alot of paints to add to thier durabilty and flexibility. Acrylic lacquer will hold up better than the old nitrocelluose.

Thermoset describes enamels. These products cure by oxidation, a chemical reaction with air. The more time that goes by the stronger they become. These types of paints are very durable and extremely chemical resistant. Rub as you will but they will take punishment. From previous posts I read about laquer over enamel and vice versa. Excellent advise, pick a system and stay with it - you'll be alot happier.

Latex is great for durabilty and chemical resistance. Try and scrub the paint off your living room wall. If it gives you the finish you want, great. Being waterborne there are no chemical compatibility problems. Adhesion sometimes - but our planes are pampered, don't sit in the weather all day and don't get beat with road salt. We have alot of leeway with our planes that in my automotive profession we don't. Experiment, find what works for you and let the rest of us in on it. Hope this helps someone out there.

Regards,
Dan
Old 02-19-2007, 06:17 PM
  #30  
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Default RE: Cheaper clear coating found

Dan....Know about lacquer in heated car. Was not left very long, but had the imprint of my seat material. It rubbed out OK but I never did it again. Can you comment on the epoxy paints for our purposes. I don't think I would spray them over lacquer, but what about enamel or latex. Should we use epoxy over epoxy or can we get away with latex. (more color options). Another question to try your patience.....Can pearl powders pe added to clear epoxy. Thanks for your input into the subject. Dave
Old 02-19-2007, 06:41 PM
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Default RE: Cheaper clear coating found


ORIGINAL: tucker1865

Dan....Know about lacquer in heated car. Was not left very long, but had the imprint of my seat material. It rubbed out OK but I never did it again. Can you comment on the epoxy paints for our purposes. I don't think I would spray them over lacquer, but what about enamel or latex. Should we use epoxy over epoxy or can we get away with latex. (more color options). Another question to try your patience.....Can pearl powders pe added to clear epoxy. Thanks for your input into the subject. Dave

Epoxies are among the strongest finishes available. Watch the thickness though, they can be quite heavy. They would work great over lacquer primer, over CURED enamel ( depending on the enamel, that can take longer than you think) and fine over latex. Epoxies are slow to crosslink ( cure ) so during the application process you shouldn't have reactions with underlying products. Lacquer can work over enamel ( not recommeded though ) as long as the enamel is cured. Oxidation is a slowwww process so that is what gets most people in trouble. The enamel isn't chemically stable and solvent ( even itself ) can cause problems.

Pearl powders ( great stuff ) can be added to any clear product and sprayed. The amount added depends on your spraying style and taste - a little goes a long way. Don't add too much or it can get a little difficult getting a even, blemish free finish. In the automotive world, pearl is added to what is essentially clear basecoat. A pure clear overlay is than added on top. That way when you rub the finish you are polishing raw clear, not pearl containing clear so the finish stays nice and even. Doing it that way on our planes would add weight though so that's the trade-off. Again, our planes don't see the outside enviroment 24/7 so we can alter the process somewhat to our liking.

Dan
Old 02-19-2007, 09:34 PM
  #32  
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Default RE: Cheaper clear coating found

I just sprayed a sample piece of litespan with "KRYLON FUSION for plastics and other type surfaces. I went on terrific. I sprayed about 4 coats about 1 minute apart. The can says 30 seconds between coats andno longer than 24 hours.

It looks great. A nice semi-glossy finish. I coated with KRYLON Acrylic "Crystal Clear" satin finish, non-yellowing, after letting dry for about 30 minutes. Looks fantastic, a very nice
"high sheen" finish but not glossy. Very smooth to the touch. No orange peel. Litespan is a very tight weave fabric and I can just barely seen the weave if I hold it to the light just right. I think, if I had sprayed one more coat of the FUSION (Yellow ) it would have completely filled the weave.

Don't know about nitro fuel proof, yet. However, I wipe my planes down after every flight or two, so I am not too worried about that. I think this is going to work, great.

Thanks for the tips and comments. I will be watching this thread.
Old 02-19-2007, 11:07 PM
  #33  
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Default RE: Cheaper clear coating found

i have a small question:
if i were to use the varathane polyurethane clear over latex, would it still yellow if i used the exterior stuff that has uv protection?
or does the water based clear resist glow fuel? i am running very low nitro (5% or less)
Old 02-20-2007, 10:25 AM
  #34  
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Default RE: Cheaper clear coating found

It is hard to describe the blotches, but they look almost like water spots.. like a pool of water that dried up. I did shake well and heat the can but it is possible that I did not shake long enough. I will check that out, I have 4 cans left. I used to have a spray booth at my last home and mixed my own automotive clear coatings using a flattening agent.. a milky white material that cut the gloss. My cowl has milky white areas on it and I painted it last. I remember rattling the can but not sure how long so that could be the problem. I will do some tests

I did discover that the krylon paints are not going to work well around alcohal as I had some some color on the clear canopy where I missed masking. It only took a q-tip and 5 minutes of rubbing to completely remove the paint using rubbing alcolhal. (no pun inte
Old 02-20-2007, 01:57 PM
  #35  
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Default RE: Cheaper clear coating found

I did a paint patch yesterday to test the Drylon "Fusion" paint. I put on 4 coats, waited one hour and coated with 4 coats of the Krylon Crystal Clear Satin.

This morning I ironed on a pc. of UltraCote to see how it would handle temperature. At 300 degrees the paint will come off on the iron if you tarry. At 250 degrees I ironed on another pc. of UltraCote and had no problems at all. The ultraCote sticks great and the paint did not get soft. Next I tried a pc. of self-adhesive UltraCote striping and it really sticks to the paint good.

Keep in mind this is less than 24 hours ago, so it has not really had any time to cure. And that's apply the base color and then clear Coating in a matter of 1 1/5 hours.

Next, I am going to run the test patch with Acetone and see what happens. Then I am going to pour 20% Cool Power on it and let is stand.
Old 02-20-2007, 02:04 PM
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Default RE: Cheaper clear coating found

Jim....To test it with fuel...run the fuel in a engine a place the test piece behind the exhaust and let it sit in the sun...This is the only way to test it. Raw fuel won't prove anything, it has to be hot exhaust. Let us know.
Old 02-20-2007, 10:12 PM
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Default RE: Cheaper clear coating found

Oops! I made a mistake. I have not clear coated the test sample yet, as I stated above. I have made another test patch. I have painted it with the Fusion Yellow and I am going to let it set for 24 hours. Then I am going to clear coat and let set another 24 hours. Then I'll test for fuel. I will take this patch to the field with me and hold it behind the exhaust.

On the 1st patch (the patch mentioned in prev. post) that had not been clear coated I took a swab and dipped it into acetone and rubbed the patch. It did begin to smear after a couple of swipes. The pieces of UltraCote and UltraCote adhesive striping are stuck real good.

Then I poured 10% fuel on the patch and let it sit about 5 hours. Took paper towel and wiped up the fuel and no yellow on the towel. It did not affect the paint nor did it penetrate the paint and covering.

I am anxious to clear coat and test. However, I am told by some who have some expereince that you need to let everything cure for about a week before you try anything.
Old 02-20-2007, 11:14 PM
  #38  
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Default RE: Cheaper clear coating found

I've been playing with paints too in anticipation of a cowl repaint on a Hanger 9 PT-19 and cowl and wheel pants on an Akrobat. Test so far are

* Rustoleum Professional high performance enamel... 24 hours later it softens immediately when a drop of cold fuel is placed on it. However, if given a couple of weeks cure time, the Rustoleum paints seem pretty resistant. The Rustoleum clear coat enamel however is not very resistant.

* Dupli Color from the auto parts store... cold fuel doesn't soften it... even within a half hour, however.... when I clear coated over the Dupli Color with some Dupli Color truck, van and SUV clear coat... after 24 hours, and tested two hours later... the fuel softened the clear coat and the Dupli Color color paint under it that previously had been totally resistant to softening with cold fuel. So... as has been mentioned... strange things happen with paints.

* The Dupli Color Truck, Van and SUV clear coat over the 24 hour old Rustoleum enamel produced instant crinkle finish.

* I'll test again after a week or so the clear coat over the Dupli Color color sample to see if it still softens.

* I've also tested one of the Dupli Color acrylic paints and they are not affected by cold fuel. Not many color offerings of the acrylic locally but one is very close to royal blue ultra coat. I will use it to repaint the PT-19 cowl.
Old 02-21-2007, 08:51 PM
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Default RE: Cheaper clear coating found

All lacquers will soften with heat, even acrylic (but not as much as celulose). Engine exhaust is the only way to be sure.

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