Spray paint mixed with clearcoat problem

[Bogdan]

Hello, later i started fixing the rust on a car i love and all good till i started painting. I went to a paintshop and bought a spray can paint with the manufacturer color code and mixed with clear coat as it's a glossy finish, not metallic.
After i sanded to the bare metal i applied 2 coats of primer, waited till the next day to cure then sanded with 600 grit the coar into the old paint to make an even surface. Then i proceeded to apply 3 coats of the spray paint i bought, with a 5-10 mins break time between.
I waited about 2-3 days to cure and now i went to wet sand with 800 grit the new paint in order to even the level difference between the new and old paint. The main problem can be seen in the picture attached:
<a href="https://ibb.co/G25FJx6"><img src="https://i.ibb.co/YkLbWRC/IMG-Pixel-Cam-Plus-20201111-163239.jpg" alt="IMG-Pixel-Cam-Plus-20201111-163239" border="0"></a> - there's a white line across the whole area where the new meets the old paint and i sincerely suspect it's the clearcoat embedded in the main paint but im not 100% sure about that, it could also be the primer ? but it's white not gray which was the primer's tint.
I tried to sand with a finer grit such as 1500 and the more i sand, the more i get of that white line. I also tried to polish with a polish sponge and 3m polish compound but it didn't remove the white thing.
Do you have any suggestions regarding what could i do to get rid of that white line ? Thanks alot!!

 

[Slednut]

Usually you spray the base coat then spray the clear over it a little larger than the base coat, the clear will then blend with the existing clear that's on the vehicle. Sand the clear with 1000,1500,2000 then buff.

 

[Bogdan]

thanks, but i have the two ( base and clear coat ) mixed together in a single spray can. Any other suggestions ?

 

[steveo3002]

primer it and sand once dry

then base coat over the primer

then clear coat over the basecoat going beyond the edge of the basecoat

thats just an F up

 

[Slednut]

Go here and join the forum, they will help you.

https://www.autobody101.com/forums/

 

[WordMan]

You have a few issues going on. First, there is no "clear blended with color" paint. There is single stage (where the color itself is what shines), and multi-stage (usually 2-stage--base (color) coat/clear coat).

I believe what you are seeing is the primer under the color.

With base/clear (2-stage), you would rough the whole panel, spray the base, then clear the entire panel. You cannot blend the clear as the parting line will always show.

You most definitely cannot blend single stage into multi-stage paint.

Hope that helps.

 

[ZRX61]

The line is caused when the original clear coat has color (& primer in this case) over it. You can't blend paint like that, you have to do the entire panel...

 

[Bogdan]

thanks for your fast replies, what i understood so far is that there is primer over the orignal clear coat and that's what the white line is about.

And the only solution besides painting the whole panel would be to apply another layer of paint over the existing one so i can have new paint over the old clear coat without primer interfering. Or should i sand the old clear coat down to base coat and then repaint with my 2k spray paint ?

 

[DTE]

You need to use a top coat blender to blend the old and new finish. https://www.jbtools.com/transtar-6363-melt-away-edge-blender/

 

[dnschmidt]

I don't think you're getting the message. There is no such thing as basecoat and clearcoat in the same can. Basecoat is a single component meterial (normally, although it is wise to mix some clearcoat hardener in with it at the ratio of 3% activator to base to prevent lifting in the case of a sand thru) and clearcoat is always a two component urethane system consisting of a resin (the clearcoat) and an isocyanate hardener. Typically mixed either 2:1 or 4:1.

Both of these require the use of a spray gun and typically the color (basecoat) can be a blow in on the areas that need it but the clear must be applied to the entire panel. It is possible to blend clear and is some cases (quarter panels) this is unavoidable but that's a level of skill way beyond that of an amateur requiring the use of a blending clear (very low solids clear which is primarily reducer) to flatten the inevitable overspray.

 

[dnschmidt]

I don't think you're getting the message. There is no such thing as basecoat and clearcoat in the same can. Basecoat is a single component meterial (normally, although it is wise to mix some clearcoat hardener in with it at the ratio of 3% activator to base to prevent lifting in the case of a sand thru) and clearcoat is always a two component urethane system consisting of a resin (the clearcoat) and an isocyanate hardener. Typically mixed either 2:1 or 4:1.

Both of these require the use of a spray gun and typically the color (basecoat) can be a blow in on the areas that need it but the clear must be applied to the entire panel. It is possible to blend clear and is some cases (quarter panels) this is unavoidable but that's a level of skill way beyond that of an amateur requiring the use of a blending clear (very low solids clear which is primarily reducer) to flatten the inevitable overspray.

 

[DTE]

you can buy 2k clear in a spray can and blend in with a spray can blender !

 

[johninct]

How to fix what you have with the paint can you have. You can't blend the way you are doing it. Scuff the whole panel and then repaint the whole panel. Caution, The old clear coat edge or your paint may lift. Also, be careful wet sanding your paint because without a hardener, it may take a long time to cure.

 

[Bogdan]

I don't think you're getting the message. There is no such thing as basecoat and clearcoat in the same can. Basecoat is a single component meterial (normally, although it is wise to mix some clearcoat hardener in with it at the ratio of 3% activator to base to prevent lifting in the case of a sand thru) and clearcoat is always a two component urethane system consisting of a resin (the clearcoat) and an isocyanate hardener. Typically mixed either 2:1 or 4:1.

Both of these require the use of a spray gun and typically the color (basecoat) can be a blow in on the areas that need it but the clear must be applied to the entire panel. It is possible to blend clear and is some cases (quarter panels) this is unavoidable but that's a level of skill way beyond that of an amateur requiring the use of a blending clear (very low solids clear which is primarily reducer) to flatten the inevitable overspray.

hmm, okay, this is getting out of my knowledge area, what i know is that i bought a spray can ( which is the one here https://www.motipdupli.com/en/products/colormatic/filling-of-cans/ipg-1232/tm-1232.html#orderinfo ) with the right color mixed by the seller and i could also ask the seller to add a clear coat to it ( i guess ) that gives shine to the paint.
This happened on the left rear quarter panel, the right rear one turned out better, although there is still a minimal visible difference between the old and new coat.

I guess back there i didn't sand off as much to reach the primer underneath.

Thanks alot for the time given replying.

 

[Bogdan]

In addition, today i sanded all the other areas which i repainted and in some of them, where i didn't use any primer in advance, the white line still showed up. It's always where the new paint overlaps the old one and i suspect it's something relating to the old original clear coat having something to do with the chemical compound of the new spray - it's just an assumption, if it makes any sense please share your opinion about this !

I also reapplied 2 new coats of the paint spray over a larger area on the rear quarter panel and i will respond 2 days from now after i sand it with 800 to let you know if it's really the paint's or primer's fault.

 

[f575gtc]

It could be a single stage paint, single stage has clearcoat properties already mixed into the color and doesn't require a clear coat top coat, you can spray one on but it is not needed.

Did the can require you to use a small plastic nail looking thing in the bottom of the can?

You could have an incompatibility with the substrate and once the new paint hits the layer already on the panel it doesn't adhere, I typically see this when spraying certain paints over older lacquer and they aren't compatible but the results are usually alligator skin like cracking.

you can usually get around this with super light mist coats but do more to build up and add more type between coats, remove the incompatible paint or add a sealer first in light coats then color.

 

[ZRX61]

In addition, today i sanded all the other areas which i repainted and in some of them, where i didn't use any primer in advance, the white line still showed up. It's always where the new paint overlaps the old one and i suspect it's something relating to the old original clear coat having something to do with the chemical compound of the new spray - it's just an assumption, if it makes any sense please share your opinion about this !

The line is absolutely caused by the clear coat between the old & new color coats. That's why you have to spray the entire panel with color, otherwise you just end up chasing that line towards the edge of the panel. First saw this back around '76 when my boss at a Jag dealer tried to respray part of a panel & ended up with a line that looks exactly like you have (except the car was red).


To help explain it:
Imagine the clear coat is actually a layer of completely different color for a moment. When you feather out paint you end up with color then primer etc. May end up with a few different colors on an older vehicle. . That's what is happening here, you're sanding a feather edge into the finish & one of the layers is clear & the rest are blue.


Or:
Picture a pack of cards, except they're all Aces & in the middle is one King. If you fan out the pack of cards to see each one, the aces are the color & the king is the clear coat/white line. You have to move the king to the bottom of the pack by spraying color over the entire panel



It's not a chemical reaction between the different paints.

 

[Bogdan]

Hello,
coming back with the final result

I think it ended up pretty good, you can still notice in sunlight conditions the level difference between the two paints, but i managed to get rid of the white line - straight up spraying over a larger area, i think the problem was either the primer showing up or something with the clear coat.

Thanks all for helping me getting through this, all the best!