Clear cracking!

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01 Nov 2019 17:34 #813409 by ErlingW
Clear cracking! was created by ErlingW
Hi guys!
Have You ever experienced the clear shrinking and cracking like it did here? This is 10 layers of clear, and they started cracking two days after the last layer was sprayed.
What's Your thoughts on this?


Regards, ErlingW in Oslo, Norway

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  • KZQ
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01 Nov 2019 19:13 #813413 by KZQ
Replied by KZQ on topic Clear cracking!
I'm not very experienced on automotive finishes but if you were to spray ten layers of lacquer on a piece of wood the finish would gain enough stiffness and strength that when it eventually shrinks it will over power the bond to the lower layers and crack just as your picture shows.
If I'm wrong someone with more knowledge, please chime in.
Bill

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  • SWest
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01 Nov 2019 20:03 #813416 by SWest
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  • DoctoRot
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01 Nov 2019 21:05 #813417 by DoctoRot
Replied by DoctoRot on topic Clear cracking!
is the crack to the primer? Typically cracking is a bi-product of material incompatibility
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02 Nov 2019 00:28 #813420 by ErlingW
Replied by ErlingW on topic Clear cracking!
Unfortunately, yes! I think I saw signs of that when sanding away the cracks last night. Still no signs of green metallic in the sanding paper though.
The primer, base paint and clear are all products from the same brand, and should go well together. Not so sure about the sprayfiller. Alle these products may be a bit on the "cheap" side. Maybe that's where my problem is? I'll do another respray of the clear today, and see in a few days if it looks better. If it doesn't help, at least I'm on the right side of winter...LOL

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02 Nov 2019 14:10 #813458 by DoctoRot
Replied by DoctoRot on topic Clear cracking!
if its cracking adding more paint will not solve the problem. You need to strip to the substrate that is failing. How long did you wait between coats? All paints are different, following the instructions for flash times is super important to ensure a chemical cross link between coats, otherwise there needs to be mechanical abrasion between coats. did you seal the spray filler before going to other topcoats?

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  • SWest
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02 Nov 2019 14:15 #813459 by SWest
Replied by SWest on topic Clear cracking!
No eBay APP ID and/or Cert ID defined in Kunena configurationHad the same problem, too many coats. This is better.
Steve
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07 Nov 2019 06:42 #813669 by PaintWorkz
Replied by PaintWorkz on topic Clear cracking!
Always good to strip away all old paint before you prime, even factory paint since they did not seem to even use primer. If you spray acrylic lacquer colors or clear too heavy and without enough dry time it will probably crack in a few weeks. The first couple cars I sprayed with a pressure pot did that.

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