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RocketManDan

RocketManDan

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Yesterday I finished my Apogee Aspire, but wanted to apply a clear coat to the finish. The paint on the rocket had been dry a couple days so I figured it would be safe to apply a clear coat. It was a two color rocket. Duplicolor gloss white and Rustoleum gloss yellow.

I decided to use the Duplicolor clear coat enamel since I used enamel paint it would make since. I went ahead a sprayed the clear on using even strokes just like I would with the paint process and also "wetted" the clear so it came out smooth and glossy.

No more than 15 minutes later the entire paint job started to check/crack. What gives?

I started to wet sand and it got to the point where it was so messed I just decided to trash it!! It was beyond the time I wanted to spend in fixing it. It just wasn't worth the added frustration. This has happened before, but not as bad.

I don't know if the can of clear is bad, which I doubt it is. It's more likely my stupidity than anything, but I mean how hard is it to spray a clear coat on a rocket. I'm at the point now where I'm gun shy and not even wanting to paint because it seems I always screw it up on the clear coats!:mad:

Sorry I'm just frustrated. I put all that time into a rocket just to mess it up on the paint!:mad:
 
Last edited:
QUOTE=RocketManDan;263709]Yesterday I finished my Apogee Aspire, but wanted to apply a clear coat to the finish. The paint on the rocket had been dry a couple days so I figured it would be safe to apply a clear coat. It was a two color rocket. Duplicolor gloss white and Rustoleum gloss yellow.

I decided to use the Duplicolor clear coat enamel since I used enamel paint it would make since. I went ahead a sprayed the clear on using even strokes just like I would with the paint process and also "wetted" the clear so it came out smooth and glossy.

No more than 15 minutes later the entire paint job started to check/crack. What gives?

I started to wet sand and it got to the point where it was so messed I just decided to trash it!! It was beyond the time I wanted to spend in fixing it. It just wasn't worth the added frustration. This has happened before, but not as bad.

I don't know if the can of clear is bad, which I doubt it is. It's more likely my stupidity than anything, but I mean how hard is it to spray a clear coat on a rocket. I'm at the point now where I'm gun shy and not even wanting to paint because it seems I always screw it up on the clear coats!:mad:

Sorry I'm just frustrated. I put all that time into a rocket just to mess it up on the paint!:mad:[/QUOTE]
That stinks. I didnt know you built kits.:rolleyes: thats good to know.:wink:[
 
Most likely problem ,is the underlying paint (enamel) is not fully cured ,this may actually take months to do ,but you are not going to wait that long, who does ?
If I clearcoat over enamels, I wait at least a week but two is better.This also depends on how thick the paint is to start with ,so longer may be better (it always is)

Sounds like the two different layers (paint & clear coat) are drying at different rates.

Sorry to hear about your frustration, but i suppose that`s how we learn .

Paul T
 
Scotty Dog said:
QUOTE=RocketManDan;263709]Yesterday I finished my Apogee Aspire, but wanted to apply a clear coat to the finish. The paint on the rocket had been dry a couple days so I figured it would be safe to apply a clear coat. It was a two color rocket. Duplicolor gloss white and Rustoleum gloss yellow.

I decided to use the Duplicolor clear coat enamel since I used enamel paint it would make since. I went ahead a sprayed the clear on using even strokes just like I would with the paint process and also "wetted" the clear so it came out smooth and glossy.

No more than 15 minutes later the entire paint job started to check/crack. What gives?

I started to wet sand and it got to the point where it was so messed I just decided to trash it!! It was beyond the time I wanted to spend in fixing it. It just wasn't worth the added frustration. This has happened before, but not as bad.

I don't know if the can of clear is bad, which I doubt it is. It's more likely my stupidity than anything, but I mean how hard is it to spray a clear coat on a rocket. I'm at the point now where I'm gun shy and not even wanting to paint because it seems I always screw it up on the clear coats!:mad:

Sorry I'm just frustrated. I put all that time into a rocket just to mess it up on the paint!:mad:
Click to expand...
That stinks. I didnt know you built kits.:rolleyes: thats good to know.:wink:[[/QUOTE]

It was a scratch build...I had some left over parts and yes I do have many kits left for sale!
 
sodmeister said:
Most likely problem ,is the underlying paint (enamel) is not fully cured ,this may actually take months to do ,but you are not going to wait that long, who does ?
If I clearcoat over enamels, I wait at least a week but two is better.This also depends on how thick the paint is to start with ,so longer may be better (it always is)

Sounds like the two different layers (paint & clear coat) are drying at different rates.

Sorry to hear about your frustration, but i suppose that`s how we learn .

Paul T
Click to expand...

Thanks Paul...

Maybe what I'll do and grab some scrap body tubes and actually document the process and see what works best. Probably a lot better than trying on a rocket. This way if I screw up it's onlt some body tubes I had laying around.
 
Azmyak said:
You also want to watch the humidity in the air whenever using aerosol sprays
Click to expand...

Today was a beautiful...it was sunny and warm and yes dry. It is as they would call it an "Indian Summer" 80 degrees outside when I was spraying the clear.
 
I just had the same problem when I went to spray one fin a different color. I am going to wait an hour and sand it down, then try again. I just want it black at this point.

I think that in the future I'll just paint a rocket body one color and maybe the nose cone another. Any other details I'll hand paint or use decals.
 
Dan,

I share your frustration at the loss.

I've found, in my own hands and the conditions in which I paint, that enamel performance is difficult to predict. I can usually get ONE CAN to spray nicely. But two cans, even of the same product but most especially different colors (even the same brand), frequently will give the problem you reported. Even if I wait a week after spraying.

Don't get me wrong, I've had things turn out beautifully with enamels, including clearcoats. But trying to predict which time it will work and which it won't drove me to distraction.

Then I switched pretty much entirely over to using lacquers. In my hands, I've never had an incompatibility problem between differnet lacquers. I've been able to spray them over each other immediately, or after an hour, day, week, or month without a problem. Clear lacquers go on just fine on top of the lacquer color coats. (though, be careful about "blush" or "milking" caused by humidity). I'll also note that lacquers go on fine over Rustoleulm fluorescents (just be careful... the fluorescents "bead" if put on over non-dry lacquers, they don't blend in).

I use Rustoleum auto filler primer (the grey stuff, I get it from Walmart), and Valspar White Primer (I get it at Lowes). These both have worked well under all the lacquers I've used, and I've mixed Rustoleum, Valspar, Testors, and Duplicolor lacquers on top of each other with no problems ever.

Of course, having sorted out a way I can get good results, I'm now trying out water-based acrylics, so I can keep painting through the winter. Too cold here for the lacquers...

Best of luck for your future work. Lots of folks report great results with enamels... I've just never been able to match their results using multiple colors.

Marc
 
Thanks Marc. I appreciate the insight and it's nice to know what happened isn't an isolated event. I have a bunch of Duplicolor enamels left that I need to use up, but I feel that maybe it is a time to switch to another method and maybe using lacquers is the way to go. They seem more versatile, but as always I'm sure there are pro and cons to using lacquers or enamels. It boils down to the method and procedures one uses when painting and of course the weather conditions. It would be nice to have a temperature controlled booth with all the cool paints and tools. but most of us don't have that luxury.

I think what I will do for now on is once I get ready to paint a rocket, practice the paint procedure on a spare body tube and see what my results are? By doing so I feel it would strongly reduce the chances of something happening and if anything does then I'm out a body tube...no biggie.
 
First off, are your paints compatible?? Duplicolor makes both enamels and lacquers. You can usually apply an enamel over a lacquer, but NOT a lacquer over an enamel! The solvents in a lacquer are much "hotter" and will usually dissolve, craze, or check enamel it's applied over. (that said, I HAVE heard of folks putting EXTREMELY thin coats of lacquer over enamel, but this is an *expert* level skill and very risky even at that...) ALWAYS test the compatibility of your paints by painting a test on a scrap piece of body tube or cardboard and seeing how it comes out. IF IN DOUBT, TEST!

Next, you REALLY need to follow the directions on the can... paints are less forgiving now than they used to be. If it says wait 24-48 hours before clearcoating-- WAIT THE RECOMMENDED TIME! Some paints can give you fits even with waiting the recommended time (I've heard horror stories about Krylon crazing/lifting/checking when a clearcoat or subsequent color coats were applied later on, even after a WEEK of curing! That's why I use Krylon only as a last resort). Some paints are DEFINITELY better/easier to use than others-- see the paint threads for more details on that...

Clear coats tend to go on heavier than we think, because they're clear and hard to see... maybe try several lighter coats 10-15 minutes apart to build the clearcoat up...

It sounds like you're rushing and paint is just one of those things that you CANNOT rush and have good results... the more you rush, the more you push it, the more likely you are to have a disaster on your hands, which will take MUCH longer to fix than any time you MIGHT have saved anyway.

With painting, like a lot of things, practice makes perfect... experiment a bit, find a brand of paint and clear you like, that works well for you and your skills and techniques, and go with it. Don't rush it, take your time, and if there's a screw-up, DON'T try to rush the repairs! Sounds like you tried to take the mess off too soon and ended up with an even BIGGER mess!

As a last resort, if the paint job is TOTALLY ruined, some lacquer thinner will take EVERYTHING off down to the bare tube/wood. Let that dry a day and start over...

Good luck and practice, practice, practice! OL JR :)
 
Marc_G said:
Test strips are invaluable!

Meanwhile, to make you feel a little better, check out this awful paint failure I had which precipitated my more or less complete move away from enamels:

https://www.rocketryforum.com/showthread.php?t=20484

The catastrophe shown above was actually a lacquer-over-enamel issue, but oh the pain, the pain...
Click to expand...

Marc

Mine looked almost as bad! Like I SAID i started to hit it with wet 220 and just said forget it...just not worth it when I could start and build another one later. Thanks for sharing!
 
luke strawwalker said:
First off, are your paints compatible?? Duplicolor makes both enamels and lacquers. You can usually apply an enamel over a lacquer, but NOT a lacquer over an enamel! The solvents in a lacquer are much "hotter" and will usually dissolve, craze, or check enamel it's applied over. (that said, I HAVE heard of folks putting EXTREMELY thin coats of lacquer over enamel, but this is an *expert* level skill and very risky even at that...) ALWAYS test the compatibility of your paints by painting a test on a scrap piece of body tube or cardboard and seeing how it comes out. IF IN DOUBT, TEST!

Next, you REALLY need to follow the directions on the can... paints are less forgiving now than they used to be. If it says wait 24-48 hours before clearcoating-- WAIT THE RECOMMENDED TIME! Some paints can give you fits even with waiting the recommended time (I've heard horror stories about Krylon crazing/lifting/checking when a clearcoat or subsequent color coats were applied later on, even after a WEEK of curing! That's why I use Krylon only as a last resort). Some paints are DEFINITELY better/easier to use than others-- see the paint threads for more details on that...

Clear coats tend to go on heavier than we think, because they're clear and hard to see... maybe try several lighter coats 10-15 minutes apart to build the clearcoat up...

It sounds like you're rushing and paint is just one of those things that you CANNOT rush and have good results... the more you rush, the more you push it, the more likely you are to have a disaster on your hands, which will take MUCH longer to fix than any time you MIGHT have saved anyway.

With painting, like a lot of things, practice makes perfect... experiment a bit, find a brand of paint and clear you like, that works well for you and your skills and techniques, and go with it. Don't rush it, take your time, and if there's a screw-up, DON'T try to rush the repairs! Sounds like you tried to take the mess off too soon and ended up with an even BIGGER mess!

As a last resort, if the paint job is TOTALLY ruined, some lacquer thinner will take EVERYTHING off down to the bare tube/wood. Let that dry a day and start over...

Good luck and practice, practice, practice! OL JR :)
Click to expand...

I used Duplicolor HBP and gloss white. I sectioned off an area and painted over the gloss white with Rustoleum yellow. Then I waited a couple days and cleared the entire rocket using Duplicolor clear for enamels and that's when it crazed, checked cracked...

I "WETTED" the clear coat and made an even coat. I probably may of put it on too thick, but I doubt it...no differnt than when I apply paint. Just wanted to make sure it was even. I would say I did 2-3 complete passes with the clear before I was done...15-20 minutes it checked on me.

I plan for now on using an extra body tube and practice the exact paint technique I plan on using on the actual rocket before actually painting the rocket. Save myself from a headache!
 
Every single person I have ever mentored in painting, has done the same darn thing.

Put way too much clear coat on! I watch them do it, then show the correct method.

Lightly.... very lightly... fog on several coats of clear. By fog on I mean keep the tip at least a 12-16inches distance depending on airframe size & for beginners usually uneven coverage. But it is drying correctly & building a boundary layer so the clear solvents won't attack the underlying finish.

It will look like crap at first. Hazy, spotty, minimum coverage. But after several turns around the rocket after waiting only a few minutes between coats, the magic happens. It will take 6-7 or more light coats to get a nice gloss.

If it takes longer than a minute or two for your coat to dry, you are putting on way too much.
As time & experience passes, the coats will become more even & the magic will happen sooner.
Painting is an art, not a science. It cannot be rushed without great skill & finesse.

Finally a big secret is to do your clear right after the finish, before an hour of drying time. The coats will not attack each other, when done that fast.

I have primed, painted 2 colors [after taping off fins] & clear coated rockets in under 2 hours, with rattle cans, Rustoleum, Valspar, Krylon, & Duplicolor. [Both small Estes & large 4in glass] But this was after many years of practical experience.

Things like sprinkling the tape with just the right amount of baby powder so it will not lift fresh paint, but not leave powder in the fresh paint are needed to pull this off.

If I could spend just a couple hours painting 2 or 3 rockets of any size with you, I guarantee you would have it licked!

Try practicing on some paper towel tubes or old rockets to develop some technique.

You can take some risks,try new application methods, won't cost more then some time and a few bucks worth of paint..... BUT next time you do it for real, you won't go nuts from screwing it up.
 
Jim

I will definitely try your techniques. I always waited a couple days, not a couple hours before applying my clear coats. And your right I probably laid it down way to thick going for that all at once gloss thinking that a light coat will leave the finish with specs all over the rocket.

One thing for sure Jim. I do plan on practicing this technique on some spare body tubes before actually painting another rocket.

Since we are on the subject any suggestions for painting rockets with a large diameter? Say 2-4" ?? Where about should the fan of spray paint be hitting the surface? How far away do you usually spray from the surface when painting the larger diameter rockets? It seems mine in certain areas always come up dry and I can never get a even wet finish on the entire rocket. This is way I am holding off on my Initiator rocket.

I painted one larger 2.6 diameter rocket about 35-40" in length and at best it turned out pretty nice, but I know it could have turned out much better. I'm always open to learn new techniques. I'm like a sponge.

Tell me about the technique of sprinkling the tape with baby powder? How much do you use?

What I'll do is post some photos after I try your techniques.

And one other thing, what causes the paint "gloss white" to yellow after using a clear coat? Too much too fast?

Thanks again!!!:)
 
Last edited:
:cry::cry:Estes SR-71. Filled, finished, primed, great black base coat, DECALS DECALS DECALS. Put a coat of clear on to preserve the decals after 48 hours of drying. Complete Crackle City.
 
BABAR said:
:cry::cry:Estes SR-71. Filled, finished, primed, great black base coat, DECALS DECALS DECALS. Put a coat of clear on to preserve the decals after 48 hours of drying. Complete Crackle City.
Click to expand...

I'm so sorry...what the heck!

Maybe we should avoid the clear coat all together or take Jim's advice on how to apply it.
 
On top of what Jim mentioned, I have moved toward the automotive clear coats, especially Plastikote Universal Clear. It seems to be less aggressive (although that is my experience and is not a scientific claim).

As an add-on, I've found that if I sand the paint before applying the clear coat, it is more prone to wrinking. If I think I should sand it, I'll do that within the window for applying more paint, like within the two hours mentioned on the can. Then, I'll shoot a light layer of fresh paint again just to expose a fresh surface.

You might also experiment with acrylic clears if an airbrush suits your style.
 
Bummer.

This is such a common thing and more often than not, and I will sound like a broken record I am sure here, it is the solvents and the flash times. Most of your spray cans even if they are or appear to be of the same product line are not always based on the same solvent.

Xylene based paints or often 'quick dry' types are usually one of the big culprits. The flash times are crucial. If it says recoat within 12 hours or wait 36 hours you better and by golly if that can tells you to wait 2 hours, do a backflip off a pier, have a sammich somewhere come back and stare at it for 3... You better! :wink:

Clear coating is its own thing. It does not go on like paint and it does not react like paint. Light, light misting coats are very important.

*Make sure you are using a clear topcoat be very wary of misguidedly grabbing a polyurethane coat unless that is what you had intended.

Crazy Jim hit it on the head with basically adding it as a you would a 'box' coat or final top coat in the finish process. More often than not when I clear I do the same thing unless I am doing a bunch of vinyl work and then clearing to seal. But then again I am using a fully matched commercial product in a commercial environment so my adversities in finish are limited to my own Darwinesque maneuvers.

Best of luck. The learning curve of the spray can is a junk science at best.

:cool:
 
RocketManDan said:
Yesterday I finished my Apogee Aspire, but wanted to apply a clear coat to the finish. The paint on the rocket had been dry a couple days so I figured it would be safe to apply a clear coat. It was a two color rocket. Duplicolor gloss white and Rustoleum gloss yellow.

I decided to use the Duplicolor clear coat enamel since I used enamel paint it would make since. I went ahead a sprayed the clear on using even strokes just like I would with the paint process and also "wetted" the clear so it came out smooth and glossy.

No more than 15 minutes later the entire paint job started to check/crack. What gives?

I started to wet sand and it got to the point where it was so messed I just decided to trash it!! It was beyond the time I wanted to spend in fixing it. It just wasn't worth the added frustration. This has happened before, but not as bad.

I don't know if the can of clear is bad, which I doubt it is. It's more likely my stupidity than anything, but I mean how hard is it to spray a clear coat on a rocket. I'm at the point now where I'm gun shy and not even wanting to paint because it seems I always screw it up on the clear coats!:mad:

Sorry I'm just frustrated. I put all that time into a rocket just to mess it up on the paint!:mad:
Click to expand...

Your running into problems with incompatible paints. Not all paints work nicely together, even paints of the same base, but different companies, won't always work well together. I've ran into this problem so many times on models off all kinds, school projects, model cars, model planes, model rockets.


It's always nice to get a piece of cardboard, 1' x 1', spray it with a paint and whenever your trying a paint combo that you've never done before, or are not sure about, just spray a bit of the other paint over the other as a test piece.
 
luke strawwalker said:
First off, are your paints compatible?? Duplicolor makes both enamels and lacquers. You can usually apply an enamel over a lacquer, but NOT a lacquer over an enamel! The solvents in a lacquer are much "hotter" and will usually dissolve, craze, or check enamel it's applied over. (that said, I HAVE heard of folks putting EXTREMELY thin coats of lacquer over enamel, but this is an *expert* level skill and very risky even at that...) ALWAYS test the compatibility of your paints by painting a test on a scrap piece of body tube or cardboard and seeing how it comes out. IF IN DOUBT, TEST!

Next, you REALLY need to follow the directions on the can... paints are less forgiving now than they used to be. If it says wait 24-48 hours before clearcoating-- WAIT THE RECOMMENDED TIME! Some paints can give you fits even with waiting the recommended time (I've heard horror stories about Krylon crazing/lifting/checking when a clearcoat or subsequent color coats were applied later on, even after a WEEK of curing! That's why I use Krylon only as a last resort). Some paints are DEFINITELY better/easier to use than others-- see the paint threads for more details on that...

Clear coats tend to go on heavier than we think, because they're clear and hard to see... maybe try several lighter coats 10-15 minutes apart to build the clearcoat up...

It sounds like you're rushing and paint is just one of those things that you CANNOT rush and have good results... the more you rush, the more you push it, the more likely you are to have a disaster on your hands, which will take MUCH longer to fix than any time you MIGHT have saved anyway.

With painting, like a lot of things, practice makes perfect... experiment a bit, find a brand of paint and clear you like, that works well for you and your skills and techniques, and go with it. Don't rush it, take your time, and if there's a screw-up, DON'T try to rush the repairs! Sounds like you tried to take the mess off too soon and ended up with an even BIGGER mess!

As a last resort, if the paint job is TOTALLY ruined, some lacquer thinner will take EVERYTHING off down to the bare tube/wood. Let that dry a day and start over...

Good luck and practice, practice, practice! OL JR :)
Click to expand...

100% accurate info. Try calling Duplicolor customer support and they'll probably tell you, you sprayed too thick.

Once atomized, clear coat will kick like a resin, meaning it gets hot. When you spray heavy it generates more heat which is what is causing the krackling effect.

Many very light coats are the only remedy other than using Future Floor Polish. I have never tried BlackJack's approach immediately following a color so I cannot comment. What works for some does not work for others. When I shoot a clear I wait no less than a week for the underlying paint to dry, sometimes more. Again, light coats. As stated, it will look like arse initially but the magic will eventually happen.

Patience my friend, patience.
 
So how many light coats do you spray 3-7? I know you are right. When you spray from a distance of more than 12" it lays on the surface kind of spotted and odd looking. So what you are saying is that it will take on that glass like finish? After how long? A week before shooting the clear ..I can wait.
 
I have watched this thread over time and sat back thinking - wow, never had this problem (and I suck at finishing).

Working on the Gizmo today I was spraying Rustoleum Black over Rustoleum Orange and wouldn't you know it... Appears we have compatibility issues. Although I was spraying in colder air than I should have, the only spots that checkered were those that had orange overspray on them. I am thinking I may give those areas another coat of primer before the next black coat and see if it helps.
 

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