# base coat reaction, 2k Primer and Prep Tips?



## theshoe202 (Mar 3, 2016)

I've had a few reactions recently when applying base coat (wrinkling), at first I thought I was applying it to heavy. After adding very light initial coats it still happened. I thought maybe the primer still hadn't gone off so on the next occasion i left it 2 days for the primer to dry. Same thing happened. Base coat is 1:1 base and stabilising thinners

I noticed it was always at the edge of the primer After lots of research I've came to the conclusion that I'm rubbing the primer to thin and the thinners is reaction with the old base coat underneath.

To counter this i plan to take the primer a couple of inches past where I normally would . Any views on this ?

What grade do you guys flat with? I've been doing 240 or 320 if it's already smooth, then finishing with 400 then 600. Also how do you flat the primer edges. Also do you re-prime any rub throughs?

All the jobs I've done have been recoverable but I need to fix whatever I'm doing wrong as its a real pain in the a#se!

Thanks in advance


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## robx1r (Feb 16, 2016)

what primer are you using?


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## theshoe202 (Mar 3, 2016)

Kapci 625 2k primer filler


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## robx1r (Feb 16, 2016)

if the reaction is that sever, either go past the old paint to metal, and use an etch primer/ stopper


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## theshoe202 (Mar 3, 2016)

The parts where I've primed over metal haven't been the issue it's been the primer edge, it's almost like I've rubbed though to the base coat but I don't think I have, I did however have a hard edge from masking tape, I plan not to have this in future


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## robx1r (Feb 16, 2016)

any pictures?


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## theshoe202 (Mar 3, 2016)

The reaction on this was in the top edge, I realise now the primed area should have been bigger, the top edge was around an Inch from the repair


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## robx1r (Feb 16, 2016)

i cant really see it,


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## Sicskate (Oct 3, 2012)

I find I usually get this reaction when painting over previously repaired/painted panels.


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## theshoe202 (Mar 3, 2016)

Yes that makes sense, all the panels it's happened on had been painted previously

It's so annoying. Here's a wing I've just primed tonight, it was just some rust on the edge and a small scratch, ive primed around 2 inches past the repair , this panels original. I doubled the masking paper over so not to get a hard edge .


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## theshoe202 (Mar 3, 2016)

Just wet flatted the wing I posted yesterday , I have rubbed through to bare metal on the very small part of the outer edge (around 2mm wide 2.inches long ) should I reprime this?


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## steve6690 (Feb 25, 2016)

If you've gone through in one place then I'd worry how thin the rest of it is. Safer just to re-prime it.


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## JCoxy (Dec 21, 2011)

If you bust through in primer a tiny bit I would leave it, you can ether dust a bit of etch over then basecoat clear coat, or in the past I've left it bare metal and basecoat straight on top. You'll get away with it being steel, but aluminum must be etched


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## REVERSiN (Sep 28, 2015)

I am sorry for the following question but is your primer spraying smooth ?
If so then why even bother using anymore than 400 to to sand it, after all 400 is all you need to make it smooth and not take too much primer off so use only 400 don't go lower.
However if it's metallic use 400 up to 600 cause sanding marks show in sun light be careful.


About your primer being gone through well it's a car setting outside with elements I recommend reprime it's safer depending on your base coat too some might actually not stick to bare metal 😀


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