Strange pattern in new paint job - help!

[tguil]

Re: Strange pattern in new paint job - help!

You have listed a whole bunch of potential causes for the bad paint job....including thick layers. "Thick" is not good whe applying paint. Regardless, you hare going to have to redo the paint job, maybe taking it down to bare metal, prime and repaint. In the meantime, drive the heck out of your car and find a local shop that will give you some advice "up close and personal". Oh, another thing that can mess up paint application is weather conditions. Laying down paint is truly an art. I used to mess some with applying single stage lacquer. I don't any more.

Tom

[bmrfan]

Re: Strange pattern in new paint job - help!

As Tom (tguil) stated - thick coats of paint are not good. I'm wondering if the thick coats of paint didn't have sufficient time to flash between coats.

How much time did you allow between layers of clear coat?

Guys, I just realised something. I actually sprayed some paint on some scrap plastic to test it before shooting onto the car. Well, I sprayed both base and clear coat, in very light coats. I decided to polish it up to see if it came out with the same result, and it's actually mirror flat and completely without the funny marks in the paint on the car, which leave me confused.. The scrap panel was FAR dirtier than the car, and hadn't been cleaned at all. It was purely there to test spray pattern and that sort of thing. The difference is, when I painted the car, I put a lot more layers on. I probably put 4 or 5 quite thick coats of clear coat on.. I'm wondering if this could be the cause..

[Trillion]

Re: Strange pattern in new paint job - help!

As Tom (tguil) stated - thick coats of paint are not good. I'm wondering if the thick coats of paint didn't have sufficient time to flash between coats.

How much time did you allow between layers of clear coat?

Well, I have to admit I was strangled for time with it getting late.. I couldn't say exactly, but what I can say is that I found it difficult to tell when it had flashed off.. obviously, with it being shiny anyway. I found myself adopting an impatient attitude with it as each coat came out so badly. I probably gave it 10 minutes in between each coat.. maybe 15 or 20, it's hard to say as I stupidly didn't time it!

[jjpcali4life]

Re: Strange pattern in new paint job - help!

normaly you dont put on 4-5 coats, 1 put on right after the other. people doing custom jobs will put 2-3 on, then re-sand and put another 2 on. most body and paint shops do 2 coats ( as long as they come out ok). Also, the other comments about air pressure, flash time, mixture etc will all play a part in how your paint job will turn out. Finally, full cure time (before applying waxes and sealants) takes about 90 days.

[the other pc]

Re: Strange pattern in new paint job - help!

...Could it have anything to do with the fact I mixed the clear coat 1:1 with hardeners instead of 2:1? ....

Ding, ding, ding... We have a winner.


Well, that was my first thought anyhow. That sort of mutant orangepeel from Hell is exactly what I'd expect from a thick film with waaaaaaayyyyyyy too much hardener.

Then again, chemical incompatibility could cause bad wrinkling too. Are all the layers from the same coating system?

Also, I'm confused by this statement:

.... I've used 1500 grit to level the surface out as flat as I possibly can, and then used a compound to remove this, and I find this very consistent web of lines and shapes sitting on the clear coat......

"As flat as possible" would be down to the bare metal. If The base layers are level you should be able to sand the top coat flat. But if the base coats crinkled you might sand through the tips of the wrinkles into the base layers before you hit the troughs of the wrinkles.



pc

[Trillion]

Re: Strange pattern in new paint job - help!

Ding, ding, ding... We have a winner.


Well, that was my first thought anyhow. That sort of mutant orangepeel from Hell is exactly what I'd expect from a thick film with waaaaaaayyyyyyy too much hardener.

Then again, chemical incompatibility could cause bad wrinkling too. Are all the layers from the same coating system?

Also, I'm confused by this statement:



"As flat as possible" would be down to the bare metal. If The base layers are level you should be able to sand the top coat flat. But if the base coats crinkled you might sand through the tips of the wrinkles into the base layers before you hit the troughs of the wrinkles.



pc

I didn't sand the base coat, but I did sand the metal, and the primer. Hmm.. I actually sanded the primer with 1200 grit rather than 800 or 600, as I found I was seeing the marks from the sanding process in the base coat after it was applied.. left me scratching my head as these are pretty fine anyway :/

Basically, everything was spot on until I hit it with clear coat. When I applied the clear coat, it had a horrible texture to it with all sorts of aberrations in it and I couldn't figure it out as all the other coats had gone on really very well in comparison. To the book, almost. Would base coat 2K thinner contaminate the clear coat? While reading the spec sheet I was given by the paint shop, it mentioned adding 10-15% 2K thinner, and since the only other thinner I had was marked 'standard thinner', I figured the 2K base coat would be the right stuff..

By coating system, what do you mean?

The primer is marked cellulose filler, which is what they gave me when I asked for primer. The base coat is a metallic, though I'm not sure what it consists of, but it was mixed there and then for me, and the clear is 2K acrylic..

[the other pc]

Re: Strange pattern in new paint job - help!

...By coating system, what do you mean?...

Coating manufacturers formulate products to work together as a system. They're designed from the ground up to be compatible and have characteristics that compliment each other. They don't just stack one on top of the other, they interact and work as a team. The final result is much more than just the sum of the parts.

When you use products from different systems and/or different manufacturers they may or may not play well together.


I wasn't asking whether you sanded the lower layers prior to shooting the top coat, although that is good information to know. What I should have asked was exactly how you sanded the top layer. I'm confused because you said "I've used 1500 grit to level the surface out as flat as I possibly can, and then used a compound to remove this." But it's certainly possible to sand the surface much flatter than seen in the pix.

Did the texture pop up after you had sanded it flat? Or did you stop sanding before it was flat?

Did you cut through the clear and expose base on the tips of the wrinkles but still have clear over base in the troughs? Or is there just wrinkly clear over the whole surface?



pc

[Trillion]

Re: Strange pattern in new paint job - help!

Coating manufacturers formulate products to work together as a system. They're designed from the ground up to be compatible and have characteristics that compliment each other. They don't just stack one on top of the other, they interact and work as a team. The final result is much more than just the sum of the parts.

When you use products from different systems and/or different manufacturers they may or may not play well together.


I wasn't asking whether you sanded the lower layers prior to shooting the top coat, although that is good information to know. What I should have asked was exactly how you sanded the top layer. I'm confused because you said "I've used 1500 grit to level the surface out as flat as I possibly can, and then used a compound to remove this." But it's certainly possible to sand the surface much flatter than seen in the pix.

Did the texture pop up after you had sanded it flat? Or did you stop sanding before it was flat?

Did you cut through the clear and expose base on the tips of the wrinkles but still have clear over base in the troughs? Or is there just wrinkly clear over the whole surface?



pc

As far as I can tell, that's all clear coat. Those wrinkles only showed up AFTER I polished the surface, it was almost like the 1500 grit sand marks were covering them. When the surface was wet sanded down it looked and felt completely flat, only with small scratches from the sanding process.. but after hitting it with cutting compound and a rotary, the scratches faded but it uncovered (or possibly instilled) these strange marks..

[the other pc]

Re: Strange pattern in new paint job - help!

How long was it between shooting the clear and sanding it down? Do you know how long the manufacturer recommends? Does the manufacturer recommend baking?

I'm guessing the paint was(/is) still curing. It actually takes weeks or even months for paint to cure. The time they normally recommend sanding and buffing is in a window between the paint being too soft (or still moving) and being very hard, requiring much more work.

They estimate that window based on their recommended mixing process, recommended spraying process and expected environmental conditions. Variation in any or all of those things can move the workability window around considerably.

If the paint was just taking a long time to cure it should harden up at some point (maybe it has already) and be stable enough to sand and buff for good.

I see it's been cool and rainy in Liverpool lately. It may just be taking a while to harden up.



pc

[Trillion]

Re: Strange pattern in new paint job - help!

How long was it between shooting the clear and sanding it down? Do you know how long the manufacturer recommends? Does the manufacturer recommend baking?

I'm guessing the paint was(/is) still curing. It actually takes weeks or even months for paint to cure. The time they normally recommend sanding and buffing is in a window between the paint being too soft (or still moving) and being very hard, requiring much more work.

They estimate that window based on their recommended mixing process, recommended spraying process and expected environmental conditions. Variation in any or all of those things can move the workability window around considerably.

If the paint was just taking a long time to cure it should harden up at some point (maybe it has already) and be stable enough to sand and buff for good.

I see it's been cool and rainy in Liverpool lately. It may just be taking a while to harden up.



pc

Thanks for the help.

About 3-4 days before I sanded it down, but after seeing the marks I thought the paint might be soft, so left it another day, and there was no change. I think I'll probably just start again!

[Trillion]

Re: Strange pattern in new paint job - help!

**UPDATE**

I briefly tried spraying the same clear coat on a test panel with the correct mix of 2:1 with hardener. The finish is just as bad, but I think this may be because I'm not using enough thinner and the clear isn't atomizing correctly and drying far too quickly with orange peel before it can level out. Pretty confident that using more thinner/reducer will sort this out, but wondered what you guys think?

Thanks for all the help so far everyone!

[Trillion]

Re: Strange pattern in new paint job - help!

Right guys, it's taken me a while, but I've finally sorted it out. I basically started again, but this time did everything to the letter. I sanded right down to the metal, cleaned my surface with methylated spirits, laid on a coat of cellulose primer sanding it to 600 before laying on my base coat and allowing it ample time to dry. After leaving this for about an hour, and thoroughly cleaning out my gun, I shot my clear, this time mixing it exactly, and allowing it 15 minutes in between coats. Three coats, no more, no less. One tack, two wet. After leaving this to set for a couple of days, I hit it with 1500 grit wet and dry leading up to 2500, and then Sonus compound and a Megs cutting pad. Here is the result!




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[Trillion]

Re: Strange pattern in new paint job - help!

Also, I'd like to thank everyone for the tremendous help. It's been a great learning experience, and I hope to use the tips I've gained in the future. Shooting at 65PSI made a substantial difference to the quality of the original coat I laid down, so thanks for that tip Juliom. I actually had to get hold of a second compressor, and run them in parallel to achieve this. I guess the manufacturers claims are a bit cheesy. Once again, thanks guys.

[the other pc]

Re: Strange pattern in new paint job - help!