Door Rust Repair (Amateur Hour)

Nero Morg

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He said it's called blushing, either the solvent got trapped under the clear coat, or it's poor quality paint.

He asked does it smell like solvent, does it have any bubbling to it, like look like water trapped under the clear coat?


Edit, showed him a few more of your photos, how long did you let the base coat dry before you applied the clear coat? Or did you do single stage?

He also asked does the clear coat feel sticky? If it's not, you may have over applied the hardener in the clear coat mix too.


Now he's going off on a tangent about other cars he's painted... RIP my next 30 minutes.
 
Last edited:

Zak99b5

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Apr 30, 2021
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Albany NY
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2003 Jetta TDI
Lol.

It was all rattle can, so premixed. Base dried about 20-30 mins before clear? Clear was 2k out of a can, and same phenomenon over the scuffed (factory) clear on top part of door as over new base coat. No untoward smells or stickiness. No bubbling of any sort.

I have used this base and clear combo successfully in the past so I don't think it's a compatibility issue.
 

Nero Morg

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Well he's gone to bed for the evening, I'll pick his brain a bit more tomorrow.

Reading back a bit more, what was the final grit you used? Usually I'd stop at 1500 then polish.
 

Zak99b5

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1500>2000>3000>5000 wet sand then polish.

I am sure I did something wrong in these steps. I had deep shine before, tho the orange peel was apparent. Sanding did flatten out the surface, but I wasn't successful in refining that to a nice gloss.
 

JB05

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Il.USA
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Golf,2005,anthracite blue
I had scratch marks on my hood after wet sanding with 3000 foam backed pad. Could not get rid of them; so I sprayed over the scratches with SEM
Blenz-In. Worked pretty well. I too used the rattle cans. Base paint from automotivetouchup.com and clear is SprayMax 1k.
 

KrashDH

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Dec 22, 2013
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Washington
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2002 Golf
Could be a few things at play here.
Weather. I've seen some interesting things happen with paint when the humidity and temps aren't controlled
Time between coats. If you don't allow the clear to flash off, you can trap gasses which can cause the cloudy condition.
Sanding. Yes you want to start with a heavier grit, but you really want to go easy with the aggressive stuff. The goal is to only knock down the orange peel "peaks". If you go too hard, you will scratch deep into the the "valleys" of the clear, this is extremely hart to get out (as I think may be your issue). You have to get everything to the same level before using compound...or at least the high spots down to the low spots.

Might be worth painting a piece of steel card or something then clearing it. Then hone your technique on that card. It's not going to hurt to clear your sanded areas again, the clear will fill in all the scratch grooves and bring back the shine and you can have another go at wet sanding and polishing.

My advice isn't professional. I, like yourself, am limited to 2k clears out of a can. But I've had some very good results on my motorcycle and various panels I've done.
 

Zak99b5

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2003 Jetta TDI
Thanks for all the input, guys.

Im debating what to try next. I’m thinking of a light wet sanding starting with 2000 and again up to 5000 and another go with the buffer.

Other option is to scuff the whole thing, lay down more clear, and try again. Would it be ok to use 1k clear at this point? It’s much cheaper than 2k.
 

Zak99b5

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Actually going to try a little wet 3000 first. Don't want to remove any more clear than necessary. It's a perfect day for this, since it's not too hot and overcast
 

KrashDH

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2002 Golf
Thanks for all the input, guys.

Im debating what to try next. I’m thinking of a light wet sanding starting with 2000 and again up to 5000 and another go with the buffer.

Other option is to scuff the whole thing, lay down more clear, and try again. Would it be ok to use 1k clear at this point? It’s much cheaper than 2k.
No, do not use 1k. You need the hardener if you want it to be a quality finish. 1k will eventually just wear off. Stick with a quality 2k if you're going to continue.
 

Zak99b5

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Zak99b5

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2003 Jetta TDI
No, do not use 1k. You need the hardener if you want it to be a quality finish. 1k will eventually just wear off. Stick with a quality 2k if you're going to continue.
I figured as much.

Looking back, I should have used rubbing compound after wet sanding, then the polishing. Hindsight.

For $115 in new supplies, including the paint, I’m happy with the rust repair.

Don’t ask me about it in a couple of years when the rust returns, though!
 

Nero Morg

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Yep definitely run compound then polish. Glad to see you got it looking better.
 

Zak99b5

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After living with it, I’m just not satisfied with the gloss. I think I removed too much clear.

Found a 2-pack of 2k clear on Amazon for what I was paying for one at NAPA, so I ordered it.

When it comes in, I’ll give it a light scuff and spray again. Now that it’s cooler out, I think I can lay down a pretty smooth wet coat and won’t have much correction to do. Will update.
 

KrashDH

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Washington
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2002 Golf
After living with it, I’m just not satisfied with the gloss. I think I removed too much clear.

Found a 2-pack of 2k clear on Amazon for what I was paying for one at NAPA, so I ordered it.

When it comes in, I’ll give it a light scuff and spray again. Now that it’s cooler out, I think I can lay down a pretty smooth wet coat and won’t have much correction to do. Will update.
How did you lay the coats down last time? Usually with a 2k they tell you to do a couple of light coats and the third being a med/med-heavy coat. Obviously you don't want runs so you just gotta watch your hand and overlap. What was your spray technique last time? Are you sure you let the clear flash completely in-between coats?
 

Zak99b5

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2003 Jetta TDI
I did a light-ish first coat. Second a little heavier, then a wet coat for no. 3. 10-15 minutes between. About 50% overlap, and pretty close to the panel, say 8”? It was pretty hot, like 90+, in my driveway, though I was painting in the shade.
 

Zak99b5

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2003 Jetta TDI
Got new clear on the door, and it's a lot better



looks better than the first go round overall, but there were issues.

as the third (planned last) coat was flashing, a gust blew the plastic sheeting I used for masking and it stuck to the paint along the front edge and a little along the trailing edge.

pulled it off, but obviously the clear was buggered a bit.

I knew I didn't have enough for a complete 4th coat, but I figured I should at least hit those spots so any future sanding would go more smoothly (see what I did there?).

the extra spray actually was laying down quite nicely, but as I got near the handle it started to run out and spray dry. So I stopped.

some orange peel and all, but I think I confirmed my suspicion that I sanded/buffed too much of the clear off.

going to sit with it as is for at least a week.
 
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