Help with weird gray haze after sanding/compound

Discuss anything after that final masking comes off.



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PostPosted: Wed Apr 26, 2023 9:47 pm
Hey everyone,

Thanks for taking the time to read this, I just signed up here because I need some help. I bought a project motorcycle and it has been an awesome experience as I've learned a lot about mechanical, electrical ect. Last year I decided to try and paint it black. Overall it turned out good but I got a little orange peel and sanded it out then used some Maguire's compound. I was left with a weird gray Haze, but I didn't mind it because the bike looked kind of cool with it. This year I was at Canadian Tire and saw they had some rattle cans of a color called black Garnet Pearl on clearance for nine bucks. I really like the color so decided I would repaint the bike. I stripped it down primed it and put three or four coats of paint then three or four coats of 1K automotive clear (I realize this is not a great clear coat for a gas tank but I figured it would be fine for a rattle can paint job). After painting it the bike looked very nice and shiny but had a bit of orange peel again. I let it cure for about 72 hours, then I sanded it with 1000 grit, 2000 grit, and finally 3,000 grit. I then use a cheap Amazon polisher and use some meguiar's compound on it. Low and behold I got the same strange gray Haze. I took some McGuire's polish to it which seems to improve the situation but it is still there. I'm hoping someone can help me understand why I'm getting this Haze, since it's happened twice with two different paints it must be something I'm doing wrong. Also if anyone has any insight on how I can salvage his paint job I would really appreciate it. I do have a couple more cans of paint and clear so I could redo it if needed but I would prefer not to. I attached some pictures of what the haze looks like. Any inside is greatly appreciated!

Before polish haze: https://ibb.co/C28ZmwG

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PostPosted: Thu Apr 27, 2023 11:37 pm
Your problem breaks down into 2 words.... rattle cans. I don't care how many coats from a rattle can you put on it just breaks down to the physics of solids. About the most real film build that you can get out of a rattle can is about 13%. The rest is solvents and propellent. An average can is about 15 ounces. Even if you dumped half a can on a surface that is only about 1 total ounce of material spread over that area. That might be maybe less than 1/2 of a mil of coverage at most. Using those sandpapers, yes, I know they are fine, will easily clip right through your coating causing this blurry mess. You just can't expect to cut and buff a surface that has little to no coating on it. A single pass with a high solids automotive clear using a gun would lay down about 6 to 8 times that thickness and we still like to see 3 coats of that because we know we are going to cut one full coat of that off in the cut and buff...... So when we cut and buff we have 18 to 24 times the thickness of surface coating that you have using your rattle can.....
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PostPosted: Fri Apr 28, 2023 2:07 am
What you see, in that "weird grey haze" is where you've sanded, but not buffed enough to restore the shine a little deeper down in the paint layer. Spray cans exacerbate the issue, as detailed above, because you don't have the paint thickness you need to buff down that deep.
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PostPosted: Fri Apr 28, 2023 8:29 am
When wet sanding with 1000 you sand until all the highs are flat,your pic looks like you didnt sand enough with 1000.
Use 2k next time and spray really heavy after the first coat,to the point it almost runs.Several coats.
If you want to go one step further let it cure, sand again 1000 until flat then a few more coats.Cure wet sand and buff.
Spray cans will always leave a textured surface,such a fine line between just right and runs.
A gas tank is probably the hardest to get right,like painting a ball.
Good luck.

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PostPosted: Fri Apr 28, 2023 10:15 pm
When the clear coat is uneven there will be un-sanded low spots. This is why you need to have an adequate amount of clear before cut and buff.

Orange peel:
Orange Peel.JPG


I use a hard block and 1000 grit to wet sand the surface flat:
Dust Mark Removed.JPG


From there you refine the scratches with 1500 and then 2000 grit using a soft block and then buff.

Here's a motorcycle tank I painted:
SPI Black.JPG


SPI Black Euro Clear.JPG
1968 Coronet R/T


ACTS 16:31

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