Hello,

So I am in the process of restoring an old Honda Motorcycle... nothing of any real value, but I am trying to do a "decent" job. The paint on the tank is shot, and its dented to hell. The side covers are ok, and so is the rear fender, BUT they are 100% plastic. So I decided to do a paint job. Unfortunately my painting skills are mediocre at best. And for whatever reason, I seem to run into the same problem with every single paint job, and I can't figure out how to correct it. After the paint dries, little bubbles form under the clear, and it looks horrid. So I was hoping somebody could offer up some tips or tricks! I have a paint gun, but after talking with the girl over at the PPG store I opted for their custom loaded spray cans which are PPG paint and Clear, but aerosolized. I am using a base coat clear coat, and I am painting the tanks, side covers, and rear fender, Metallic Blue. I will be spraying them indoors.

The problems I have to contend with are, bubbles under the clear coat, which I know will appear (ugh!), and I'm not quite sure what i need, or how to paint plastic side covers and fenders... Also not sure what grit sand paper to sand with prior to painting (600?).

Dan

Thanks Kevin, I was all excited that somebody FINALLY Answered me.

LOL

DG

I'd just take the pieces down to a shop.

Couldn't be that much $$ to shoot.

Is the clear not bonding to the base coat and beading up, hence the bubbles? Or is there literally air trapped under there?

are you putting down too much ? are you sure everything is good and clean? how much time between base and clear?

If it's actual bubbles forming in the clear I think you've got it mixed too hot. Been about 20 years since I sprayed, but I did custom Harleys for 9 years. I'm way behind on the new paints that are out now so I can't be sure, but that's what it sounds like. When I was spraying we could still get lacquer.

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I was quoted $350, assuming that I handed the body shop everything already sanded. That's ridiculous.. I rather gamble with $100 first. Plus if it comes out good, I get the satisfaction of doing it myself.

I feel more confident this time around because my Center Console came out AMAZING!



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I have been reading online about using solvents to prep the area prior to painting. Long story short, some solvents get caught up in the primer and then when you paint the out-gas and cause bubbles.
BUT I don't think this is the case. I feel like the Base Coat Out-gasing is causing the bubbles. But I am not sure how to fix this problem. Keep in mind I have not painted this tank yet. These are previous paint jobs gone bad. Just trying to "prevent" this from happening.
I usually follow the directions or tech sheet. In this case I was not given a tech sheet.

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Again, good question. I usually follow the tech sheet; in this situation I am not provided with one. How long should I wait in between coats? Show the coats go on light and thin, or heavy and thick? How long should I wait before clearing? How should the clear go on, thick or thin?

Thanks,

DG

Yea, $350 is nuts. That's why I paint all my own chit.

Here's the deal, the solvents, prep solvents - don't use them at all. The only way Ill use solvent is on top of epoxy primer ( 2 part, gun sprayed).

The plastic's old and some of the solvent will remain on it no matter what. Rattle can primer sometimes will do the same.
If you wet sand the plastic with 220, it may have a rough texture afterwards. Use the 220 to get rid of the old paint then sand with 400 using progressively lighter pressure.

On the 400 sand, put 5 drops of Dawn in a half gal. of water and soak the 400 10 minutes before you start sanding.
Shoot the primer and let it dry fully, sand with very light pressure with 400 or 600. If there's any roughness on the plastic or any bare plastic, primer it again. The final sand is more like wiping it down than sanding.

Let the primer dry overnite. Shoot the metalic and again let it dry overnite. (I know what some of the tech sheets say about recoating but, I've had better luck letting this stuff dry overnite).

If there's dust on the metalic the next day, use a microfiber tack rag, not the sticky tack rags (I've had bad luck with them too). Shoot all the clear coats thin but not too thin. Too thin will look grainy, just shoot until the coat looks slightly shiny and be sure that you're not too close to the part with the rattle can, 12 to 18 inches works best. I'd go with a 2 hour dry time between coats and only do 2 clear coats.

If you get a run in the clear, it can be scrapped off VERY carefully with a razor blade followed up by LIGHT 600 & 1200.

Here's my Yamaha that layed outside, under a tarp for 15 years:

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Hey Bill, Thanks for the tips... I think I follow. I will list what I think the process is real quick just to be sure

1. Sand down tank with 80 Grit
2. Sand down side covers and fenders with 220 grit followed by 400 grit
3. Fill in dents on tank with bondo
4. Take down Bondo, and finish with icing.
5. High build primer the tank and side covers and let sit overnight
6. Block everything with 400 grit, then 600 grit
7. Wipe down with lint free rag
8. Paint stuff, applying a thin even coat
9. Let paint tack up, and reapply another thin even coat
10. Let paint dry overnight
11. Clear with thin even coat, wait 2 hours, and clear again with thin even coat
12. Wetsand and buff

Am on on the right track? I am still a little unsure of how to apply the coats

DG

Yea, Dan, sounds good.
In step 6 youcan skip the 600 alltogether.
7. If you can get a microfiber tack cloth, they're good, I think I got one at Wallymart or Home D.
8. The metalic coats, not too thin where they look grainy, but slightly wet (shiney). Use 50% overlap to get to the slightly wet and because metalics need that much overlap to be even and not blotchy. Make sure your lighting is good, like a haligon work lite or sunlight thru a window.
9 A good way co check ow tacky the paint is is to touch on any masking tape used.
11 Two hours is close between the clearcoats, again touch some of the masking tape.
12. Your using clear in a rattle can right? What I would do is shoot a piece of sctap metal/plastic with both the metalic and clear to see how dry it gets overnite or in 2 days. That way you can wetsand and but a scrap piece without screwing up a good part. The clear drys different depending on temp and humidity.
I usually clear coat with a gun and 2 part PPG urathane.

When you wetsand the clear, again use a bit of Dawn in the water, acts as a lube and soak the 600 in the water for 10 min. You can try buffing after 600 on the scrap piece.
Light pressure on the 600, take 3 or 4 sweeps and wipe dry with a paper towel. If the dull surface looks even, you don't need to sand further.

To tell you the truth, if you aren't building a show bike AND you don't get any runs in the clear, I wouldn't even bother with the sanding and buffing after the clear.

My helmit has never been sanded and buffed. This was painted with numerous kinds of rattle cans and topped with PPG Concept 2000.
http://www.corvette-guru.com/modules/ ... hp?topic_id=8366&forum=55

Thanks for the tips Bill. That's a really sick helmet by the way (I can't believe that's rattle can'd, your obviously gifted) I went back to the store today, after reading online and realizing that the primer I had wasn't going to work, so I picked up the correct stuff, and a tube of 2part Icing.

I had a few dents in the tank. One really bad on on the right hand side, and two tiny dings on the top. The top left ding got Bondo and Icing, while the other side just got icing.

I am not feeling too confident after icing and sanding down the tank with a sanding block. The tank feels smooth to the touch, but when I looked at it after priming it, there are area's that look wavy and uneven. Yet when I run my hand across the tank it feels smooth, and straight. I am wondering if when I paint this thing it will look wavy or if it is an optical illusion because the primer is light than the icing and the icing is showing through the primer. To test my there I heavily guide coated the tank. Looks good guide coated. It will still need a final 400 buff before I seal it up and paint it on Saturday.
Had this been a door or a hood I think that the blocking would have been a HECK of a lot easier, but this tank has so many contours, I am just not sure how to tackle it properly. Whats a good "rule of thumb?"

Take a look at the pictures of today's efforts. I don't have any bondo or dent pics. sorry,

DG

[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank008.jpg[/IMG]
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[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank012.jpg[/IMG]
Done for tonight....
[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank013.jpg[/IMG]
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Getting the bondo and glazing puddy smooth is a pain, I'm really slow at it and always have to glaze, primer, reglaze etc.
Are you using a hard sanding block on any of the curves?
A soft block that conforms does a better job. I've made some soft blocks out of those blue exercise mats. I now use Durabloks.

Shoot a coat of the metalic on and if you can see the waves, just scuff it, reprime and use the icing to level it.

Thanks for the compliment on the helmit, if you really want to get sick, I'll tell you what kind of paint mix was in the different rattle cans.

Here's some more of my paint jobs. Note that this is my fiberglass work too.
http://www.corvette-guru.com/modules/ ... hp?topic_id=6586&forum=55

Well, got out there and laid the paint and clear down today. I must say, I am pleasantly surprised with the outcome of the tank. I did make a mistake I am hoping I can fix, but overall, the paint laid down perfectly. The clear on the other hand gave me a little trouble. Its a really watery clear and it dripped off the take in the absolute worst spot. Notice Pic #3, you can't see it, but all along the bottom edge of the tank you can see drips. I am an excellent cut and buff, but I also know how thin Rattle can clear is to start out with. So I don't know if even I will be able to remove the clear without running down to the paint. Its going to be a really tough cut and buff!

Take a look...

DG

[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank016.jpg[/IMG]
[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank019.jpg[/IMG]
[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank017.jpg[/IMG]

Dan, what you can try on that is to hold a single edge razor blade with both hands, by the sides and gently scrape the run off. They also make a tool to hold a blade for this.
You need to take it slow and be very careful not to let the blade touch anything but the run.
When the run gets down close to the level of the rest of the clear, take some 600 wet wrapped around your finger and make 3 light swipes on the run, wipe with paper towel, inspect, repeat.
Take your favorite LIGHT polish compound & lightly buff.

You could mask off the run for more protection BUT you have to make sure the clear is totally dry and set or you'll get marks fom the tape.

If I can presume to suggest, on the next project, go with 2 part urethane clear and your gun overtop of the rattle can paint. The 2 part is much harder, more protection.

Bill,

Thanks again for all the tips!!! I decided to get out there today, and try the wet sanding and buffing method I normally use for old paint. Worked like a charm. The results of the tank and side covers are outstanding. I am very surprised to be honest. I can honestly say it came out better (using spray cans) then the local (so called) body shop would have done for double the cost. Check out the pics... These were taken during.
I first sanded on a rubber block using 1500 grit 3M
Then I hit the edges and rounded areas with 2000 grit
Checked the level of the clear by wiping with a squeegee and and looking to see all the shiny-ness was gone. When I got it down to an "acceptable" level (remember, spray cans aren't able to lay clear the same thickness as a gun), I polished it out..
First with Meguiars Ultimate Compound on a Orange Pad
Finishing with Menzerna 106FF on white....

DG
[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank021.jpg[/IMG]
[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank022.jpg[/IMG]
Lovin the metal flake!
[IMG]http://i142.photobucket.com/albums/r97/BG528/MotorcycleGasTank023.jpg[/IMG]

Beautiful

Why did you paint the rear end of a C5 on it?







Nice work!

Excellent Work!