paint job gone bad and need help

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63dartman

63dartman

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I started painting my son's 70 mustang(I know) and I'm not sure where I screwed up. It was a single stage urethane crossfire metallic from NAPA. I have runs everywhere. I think I screwed up by trying to lay too much paint on the first coat and using a 1.4 tip. What size tip is correct for single stage urethane and what can I do to fix it? Can I just sand off the shine and lay a few more coats?
 
After it dries good you should be able to sand out the runs and spray it again. You will have lots of material on it by the time you are done so it might not age as well as it could, it might be prone to cracking.
 
I had runs in my clear coat. I was told by an old pro to use brand new razor blades to plane the runs down, before wetsanding to even it all out. Hold the razor blade with two hands, one on each side of the blade and scrape off the excess material. Once it's as low as you dare to go, wetsand the panel to even it all out. After that you can re-shoot the panel. If the runs are bad, sanding them without taking the razor to them first could make you cut through the surrounding paint all the way to the primer, or worse.
 
Thanks for the razor blade tip. If I plan on shooting the whole car again do I need to scuff it to remove the gloss. Thanks for the replies too.
 
Shaving the runs is a good tip with a razor blade. Then wet sand the bad area's you can read the spec sheets on the paint to see how long the recoat time is. Personally I would knock any orange peel, runs, dirt nibs, and any imperfections down and re paint the car. Do some test panels first, check your reduction also. Practice a bit before you get on the car again.
 
Suggestions so far have been good, although they will only work for a solid color. You said its a metallic paint, if there is any metal flake in the paint you'll have to repaint after you cut down the runs or sand them down.

Reason being that the metallic flake in the paint will have a higher concentration in the area of the run. Even after the run has been made level with the surrounding paint the metal flake will show where the run was. This is also important if you're planning on spot painting the car to repair it. Metallic paints are very hard to blend, because the concentration of metal flake depends on the air pressure, distance of the gun from the car, even the temperature. I've seen metallic paint out of the same can not match with the surrounding panels simply because it was sprayed on a different day, with spray gun settings, air pressure, paint mixture and painter all being the same. Not to say is can't be done, or done to a level you're happy with (if this isn't a show car), but its definitely harder to pull off than a plain old solid color.

I would cut down the big runs, flat sand the whole car and repaint. Depending on the spray gun used you can lower the volume of paint vs air with the guns adjustments, and lay down a very thin coat of paint. You already have a heavy base coat, you just need a uniform top layer and you're good to go.
 
use the razor blade tip, its a good one.

then sand down all imperfections as was mentioned above.

make sure you have the right size tip, your painting in permitting weather.

air pressure is regulated correctly.

keep your gun 8"-12" away from the surface your painting.

do clean sweeping motions and be sure to overlap with each pass to insure even color coverage.

don't move to fast or you could get a gritty textured paint but don't move to slow as you can get runs.

YES ALL GLOSS NEEDS TO BE GONE......or the paint will not stick to the surface very well and could lift and flake off.

check to see what the paint says the re spray time window is and make sure you follow all the directions that paint says to do ( mixing and so on ).

you could also use slightly less paint thinner and add a little extra hardener and or fish eye reducer and or a gloss promoter .....thicken up the paint a tad bit by using less reducer which in turn will make it easier to steer clear from runs.

I always start with a "dust coat" ....just a quick pass around the car....not enough to give full coverage (you may still see primer) .....but it acts as a base that will allow the following coats to better adhear to.

then I let the paint flash out for 5 or 10 minutes and come back through with my "cover coat" which is where I would go through and make sure that the car has even paint coverage with uniform color.

than after that coat has had time to flash off.

I come back through with my "gloss coat" which is where I slow down my speed a little bit to build up my last coat slightly more than the previous coats which in the end will give a glossier finish.

also .....don't worry if you get a couple imperfections....a minor run here and there and what not....you can razor blade it off ,wet sand with 800,then 1200 and if you want you can even finish it off with a 2200 or so......then take some rubbing compound and a buffing wheel to it and it will shine up smooth as glass and you would never know that there was an imperfection. ( sometimes metallic paints still show a "trail" of metallic where a run was fixed......but depending on the color and amount of metallic that will very.

hope some of that info will help you out and good luck....hope you get it fixed up and keep us updated on what you manage to work out!
 
72bluNblu has the best advice. It is almost impossible to sand a metallic. It destroys the pigment. The one bad thing about special effects. Also another thing to watch out for is what is referred to as "tiger stripes". If you don't get equal coats between passes that is what you end up with. Practice, practice, practice if you can. Good luck! Let me add this. The 1.4mm tip for your gun is a good size. Oh, and since it is a single stage paint, there is nothing else he adds to the coating. Just lay it out lightly, put a piece of paper on the wall and adjust your gun before spraying on the car. Start out with less, you can always add more. Overlap your coats by about 80%. That should eliminate the tiger striping I mentioned above.
 
72 and louie have done this before.Good Luck spot sanding metallic runs,its not impossible but very close.
 
oops....just noticed he said it was single stage.

well...some of the tips I mentioned still apply.
 
The fact it is a single stage and metallic has no bearing if he is going to repaint the car.
 
:poke::dontknow: Why worry about cutting with a razor????? Its single stage and sanding it destroys the Hue and the metallics will appear silver after buffing therefore, it will need to be repainted. Spot blending single stage is a ***** especially for the novice. Blocksand it all back down and reshoot it. That paint is cheap enough. Another reason to use Basecoat/Clearcoat. More forgiving to the novice. Just wear the right body/breathing equipment. It's hard to type how to use a spray gun. There are lotsa vids on youtube that can give you an idea of the spray procedures. Just be sure to use this little hint, Spread your pinky and thumb as far apart as you can. That should give you a distance of 10inches, stay that far away from the panel and have the fan of the spray gun the same at that distance(10"X10"). Moderate speed from front to back with a 50% overlap each pass. I start at the bottom of one side and proceed upward across the roof, hood and decklid and down the other side. This should be done inno more than 15-20 minutes. The flash time should be fairly close. If so, start allover again on the first side for the second coat.
 
67Dart440GT said:
The fact it is a single stage and metallic has no bearing if he is going to repaint the car.
Click to expand...

Sure it does, especially if he plans on re-shooting a single stage metallic! :-D

I only say to cut the runs down because they're easier (and faster!) to cut down when they're soft vs. waiting for that big glob of paint to dry and then spend an hour sanding it out. Either way the whole thing will have to be sanded.

I've sanded plenty of single stage paints, as long as there's enough paint (ie, you don't sand it so thin you can see the primer) it will not change the hue. Hence "color sanding" with 1200+ grits. However, sanding a metallic is pretty useless since whatever was there before will probably still be visible as a "shadow" when you're done because of the metal flake concentrations.

Buffing a metallic will not turn it silver unless you buff all the paint into oblivion. At that point you'd have ruined whatever kind/color of paint you were buffing anyway, base/clears included. That's not a metallic paint problem, that's a buffing problem.

Single stage paints, IMHO, are about a million times easier to deal with than a base/clear. You can always color-sand, polish, buff or even spot paint a single stage (ok, not so much if its a metallic, there's always an exception). Not so with a base/clear. Once that clear goes on, you're pretty much stuck with what you've got. And no worries of that clear coat checking, peeling, or turning white, or yellow, as I've seen numerous clear coats do. Hell, the clear on my Challenger is peeling off as we speak (no, I didn't paint it, I have the PO and probably maaco to thank for that :angry5:). True, single stage paints require a little more work to keep up, but if you know how to do the work I think the result is much better.
 
I was worried about the razor "digging into the paint" so I was advised by a local car buddy to go to the local auto body store where I bought my paint from and pick up a "nib file" it was cheap like 15 bucks and worth it. It leveled out the runs in the paint without taking anything else off even if i wanted to. Its a great tool and worth the extra couple of bucks for me having the assurance of knowing I wont be taking anything else but the extra run off the car. Hope this helps.
-Joe
 
The reason a razor blade works well or a nib file is because you can take off the majority of the run without breaking through by block sanding, then finish with a block. If you break through a lot of spots it will require spot sealing, depends on how bad the runs are you could get away without re sealing the car. Either way its pretty obvious he was not going to buff and planned on re shooting the car. ](*,)
 
If you break the corners off the razor blade it helps to keep it from digging in to the paint while you're removing your runs. You'll still need to block sand the hell out of it until all the shiny spots disappear.
 
Another trick to to bend the razor blade a little. This will help avoid digging into the paint with the ends of the razor.
 
Couldn't I use a file to round off the corners on the razor blade? Thanks again everyone. as it looks right now I am going to remove the runs, sand back down to painting standards and reshoot it. I'm not sure if I'm going to get it done before spring or not, the weather is fading fast here in New Mexico. I will post some pics later this evening. I think my biggest mistake was trying to lay too much paint on the first pass. My first instict was to try and get good coverage on the first pass......I sure wish I would have posted this BEFORE I started:(:( Another lesson learned:)
 
Here are a few pics.....I have several places that look like this. I still have about a half gallon left. Possibly enough to add a few coats when the repairs are done. How long will the paint stay good in the can?
 

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The paint will normally keep good for some time.

read the label and see if it says what the shelf life is.

and keep it in a warm place also and try to shake the can up every couple of weeks so the metallic doesnt fall to the bottom and glob up.

and yes it looks like you can the paint a little heavy in some areas.

(hey it could be worse...here in MI its getting colder and snow will be flying soon)

also another tip......with metallics ....after laying my last coat (gloss coat) I try to kind of mist my paint on where I just painted......that way the metallic has a uniform distribution.

hope you get it all figured out and looknig good.

cool color by the way!
 
Thanks, I will get er done. I'm pretty confident about where I went wrong and how to fix it thanks to everyone here. May have to wait till spring time though.
 
Ive used Crossfire a couple of times and man ,it is VERY easy to run.I had to add a little less reducer than what it calls forI agree,let it cure and when you are ready to repaint,take a blade like everyone suggested to knock the majority of the run out,and use a block with 400-600 wet to block out the rest.Since you are repainting it anyway,dont worry if you bust through to the primer because I can almost gurantee that you will.Just spot seal the spots you broke through.Sand the rest of the car with 600 wet and use a gray scotch pad to scuff up the edges so it does not peel.When I use a single stage,I try not to use too "wet" of first a coat.Spray your first coat not too wet,but not to dry either.Make sure the fluid control is adjusted right because that can cause too much paint to flow out.Temperture is also a factor.If the surface you are painting is too cold,it will run.70 degrees is an ideal temp to paint.:cheers:
When I first started painting,i was the king of runs,lol,and sometimes I still do run paint,it happens and sometimes my boss would tell me whenever I ran paint that now hes going to have to charge the customer extra for the runs,he was joking of course.:-D
 
Thanks for the tips. I was thinking about reducing the the reducer a little to help out. It did seem like the paint was very thin.
 
Part of the whole thing is they gave me a cr733 reducer which is for clear coat. Napa rep told me it can be "substituted for the original cr233 reducer on the spec sheet. Idon't know if it is true or not. I would think the reducers have different part numbers for a reason.
 
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