[Oxyg3n520]

Hey guys. So I've been having trouble with my lip spoiler that I have spray painted myself. I bought the paint from automotivetouchup and put on adhesive promoter, primer, base coat, and finally clear coat. Well, since the beginning until now (about 3-5months ago) the clear coat has been feeling sticky and somewhat melting in the sun making it vulnerable to particles like dirt and bugs to get stuck and stick into the clearcoat/basecoat. This left my lip feeling rough and basically have to be redone to fix. Has this happened to anyone and did I do something wrong lol

Here's a pic:

 

[SLIKRIK]

did u let it cure properly? i'd say do it again or have it done professionally.

 

[Oxyg3n520]

Hmm I did let it sit for about two days before putting it on. And hmm. How would you take it off? It seems to be glued on pretty tight(3m tape) and would my car's paint where the lip sits have lots of scratches after I take it off? Since I'd assume dirt and grime probably went under the lip and stayed there because the 3m tape is only a thin s trip.

 

[Aragrev7]

You will have to take some fishing line or yarn (believe it or not) to cut through the 3M slowly by sliding it back and forth under the spoiler. Do this when the tape is HOT. Hot temps outside, or even better -> heat gun. You will be left with a nasty mess of 3M most likely. Goo gone will get it off. Do not use a metal scraper or anything. Throw on a mechanics glove and rub it off by hand.

When you spray paint, you have to do it in LIGHT layers. Let each layer dry according to the time specified on the can. You might even have to wait longer for the clear coat. Don't rush it. It looks like you loaded on the layers without letting the coats dry in between. So now the whole stack of layers is trying to dry through to the top. The chems used to keep the paint liquid are trapped under the top layers and are trying to seep out. It would dry eventually. Also, as the cans usually state, if you leave a coat for more than an hour or two, you'll have to return to it after something like 7 days.
I know this through experience. Exactly what happens to me on my first eBay spoiler.

Lastly, use some good spray paint. Montana's is really good I hear.
One more tip I use, is to put the cans in a hot water bath to keep if hot. And heat gun the as I go. It keeps them really thin. Just be aware that the cans are under pressure. You might even want to skip this if you're not sure what your doing.
Really best bet is to get a gun and compressor, or let a shop do it.


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[tottenham12712]

You either did one of two things or both.

1) you sprayed too much on at once without letting the paint flash in between coats

2) the correct amount of curing agents were not used in the paint/clear

The only way to fix it is to totally strip it down, sand it, bondo if needed, sealer/primmer, base, clear.

I personally like PPG paint. If you want a simple kit I would recommend expresspaint.com, they even come in aerosol cans if you need. Every paint is different and you need to read the specs regarding it before spraying.

 

[Oxyg3n520]

@Aragrev7 Just wanted to make sure. Does one coat mean just one single left to right motion or a few thin layers before calling it one coat? Because on videos I see some people spray like 4 or 5 quick layers of clear before they call it the "first coat."

@totten What's curing agent?

and thanks for the feedback

 

[SeaJay]

I don't know for cars but I've painted other things that required multi-coats.
You lightly spray enough paint to cover the surface for 1 coat.
If the paint drips or looks heavy then it is too much. Too thin is ok.

 

[tottenham12712]

@Aragrev7 Just wanted to make sure. Does one coat mean just one single left to right motion or a few thin layers before calling it one coat? Because on videos I see some people spray like 4 or 5 quick layers of clear before they call it the "first coat."

@totten What's curing agent?

and thanks for the feedback

Automotive paints are very different than your average can of rustolum. They contain solvents and reagents that evap out of the paint and cause it to harden. If you apply to much paint to quickly with out the proper flash time those solvents cannot get out in time for the next coat, in this case the paint will dry but it may take days or weeks, and in the process it will soften the coats above it until they evap out.

If the paint was mixed incorrectly (either by yourself or the manufacturer depending on the paint) than the same can occur even with the proper spray technique.

The way you spray the paint really depends on the type of paint you are spraying, its hard to answer without knowing if its a single stage, dual or tri stage paint. Usually for a single stage paint you start with a "dust coat" which just adds a very light base coat to the panel. After the paint flashes (15-30m) you can spray another coat about double the amount as the dust coat. Once you have an even coat, you continue to spray your base until you get to the color you would like to achieve (15-30m in between coats).

 

[Aragrev7]

^ yup. Exactly. You should be able to see most of the surface. 30-50% coverage only.
And again, too thin is better than too thick.


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[Oxyg3n520]

Finally deciding to fix this problem right before my summer vacation ends. Here to ask what grit sandpaper you guys think I will need to get all that paint off of the lip so I can start all over again from the bottom

 

[tottenham12712]

I would use something pretty rough like 220, once your down to your base material (get it all off, use stripper if you need to) use 320, 400. Spray a primer(two coats), sand 400, 800, might need 1000 here as well. Spray your base 1st coat is a dusting, second in 2x as much, after that keep spraying even coats until its the proper match. If your base did not lay flat (it probably wont since im assuming you dont have a spray booth) you will need a high grit sand paper (~2000) or you will end up removing too much color. Clean your surface, let it dry and than spray your clear, first coat slightly heavy than lighten up as you go along.

Hope that helps!

EDIT: You can use dry paper to remove the crappy paint but make sure you use wet paper after that(in makes for a much smoother finish)

 

[Oxyg3n520]

I would use something pretty rough like 220, once your down to your base material (get it all off, use stripper if you need to) use 320, 400. Spray a primer(two coats), sand 400, 800, might need 1000 here as well. Spray your base 1st coat is a dusting, second in 2x as much, after that keep spraying even coats until its the proper match. If your base did not lay flat (it probably wont since im assuming you dont have a spray booth) you will need a high grit sand paper (~2000) or you will end up removing too much color. Clean your surface, let it dry and than spray your clear, first coat slightly heavy than lighten up as you go along.

Hope that helps!

EDIT: You can use dry paper to remove the crappy paint but make sure you use wet paper after that(in makes for a much smoother finish)

That explanation really helped thanks. Can you explain to me why the first coat of clear should be slightly heavy? Just cautious because I think that's how I screwed up my first time, but instead i did all heavy coats:rolling_e

 

[tottenham12712]

That explanation really helped thanks. Can you explain to me why the first coat of clear should be slightly heavy? Just cautious because I think that's how I screwed up my first time, but instead i did all heavy coats:rolling_e

Not massively heavy just slightly more than an average base coat, this helps eliminate orange peel as you spray lighter and lighter on top of that first coat of clear. You might need to sand down your clear and try a few times but you will eventually get the technique.

Keep in mind different paints work differently, so you might need to do a little research on the paint.

 

[Oxyg3n520]

a quick question. Trying to sand everything off right now but even with 80 grit sandpaper, it is taking forever. Do I have to sand off all my paint and primer or can I just sand until I get past the clear and almost to the primer and start repainting?

 

[tottenham12712]

a quick question. Trying to sand everything off right now but even with 80 grit sandpaper, it is taking forever. Do I have to sand off all my paint and primer or can I just sand until I get past the clear and almost to the primer and start repainting?

Are you doing this by hand? I would use either an air sander (you can get a cheap on from harbor freight) or even an electric orbital. Doing it by hand will take forever

Fiberglass: Klean-Strip Automotive

ABS/flex plastic: Klean-Strip Automotive

If you use a stripper make sure its safe for the material you have. Make sure before you spray you primer you sand it in steps up to around 300 or so, 80 is way to rough.

 

[Oxyg3n520]

haha after "forever" I went through the clear coat but most of the old base coat is still there. Just going to prime and paint again from there, hopefully it turns out good.