sanding Duplicolor causes metal flake variance vs unsanded

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PostPosted: Sun Apr 09, 2023 10:16 am
I cannot figure it out
If I lay down light coats of well shaken Duplicolor paint, evertime I go to smooth sand or feather in the Duplicolor, it gets a sparkly metal flake look which is quite different than the OEM paint look. If I do not sand them the color match is about perfect. So every place I repair then sand has a highly visible difference. The cans are well shaken, I tried 2 cans bought months apart. Color is for code PB7, Patriot Blue .

If I do not color sand new paint maybe then just clear it will that be the thing to do?
I have tried, 600, 800, 1500, 2500 grits, they all end up with the same issue. It is like the metal flake on the OEM paint is less pronounced or deeper into the paint layer. And the new Duplicolor is all floating closer to the top of the paint layer.

I sand the OEM blue paint; this issue does not appear at all.


picture of a sanded scratch repair which I have now painted and sanded 5 times.
https://photos.app.goo.gl/PeDV6S1mLng5mxgq5

Pic of a different but unsanded repair spot.
https://photos.app.goo.gl/Dd3TxrsW62t2FxVg6



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PostPosted: Sun Apr 09, 2023 2:07 pm
Rattle can Paint bombs are very frowned upon here at 101.

That said being said, You never Sand Base coat! Regardless if it comes in a Rattle bomb or is mixed and sprayed through a Gun Just Clear it.
Their are some exceptions but are rare ALWAYS read your Tech sheets and follow their instructions, ALWAYS!
Last edited by Doright on Mon Apr 10, 2023 1:29 pm, edited 1 time in total.
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PostPosted: Sun Apr 09, 2023 6:36 pm
:welcome: you can't sand virgin metalic base coat. what happens is you sand the color off the flake and end up with the silver showing that you have. the reson this doesn't happen with the oem paint on the rest of the car is that it has clear over it and you're sanding the clear only. i would try and blend the new aerosol that your useing. look at the sticky's at the top for blending. it will be with a spray gun, but you can do the same with a spray can to some extent. then clear it.
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PostPosted: Mon Apr 10, 2023 5:18 am
interesting that sanding color coat is bad idea? So no feathering of edges?

I got a big improvement. Mostly by spraying many more layers on. I then used a medium compound on it to smooth it some.

I plan to spray clear coat over the spot too.
https://photos.app.goo.gl/PPYkRzoqCUtWBX8K7

I bought Meguiar's Ultimate Polish, High-Gloss Pre-Wax Car Polish, 20 fl. oz.
Will use it with a buffer I have.
This is supposed to bring out a deep clear gloss look

https://www.amazon.com/gp/product/B06X4 ... =UTF8&th=1

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PostPosted: Mon Apr 10, 2023 6:32 am
sdowney717 wrote:sanding color coat is bad idea?


Very bad.

sdowney717 wrote:So no feathering of edges?


Blend edges by releasing trigger while moving gun.

sdowney717 wrote:I then used a medium compound on it to smooth it some.


Also a very bad idea. The compound will likely result in fisheyes when you spray the clear.

Basecoat is intended to be covered with clearcoat as soon as it has flashed off, so 15-30 minutes, depending on ambient temperature and thickness of the base.

At this stage the safest thing you can do is clean the panel using Prepsol then very lightly, but evenly, scuff with grey Scotchbrite. Flash for 15-30 minutes then tack the whole panel. Apply a coat or two of base, not heavy, over the repair area, blending out around the edges. Allow to flash then clear the whole panel.

Use 2K clear, which is available in spray cans. Allow that at least 24 hours to cure and harden then denib, wet sand if necessary and compound on your buff, followed by polish.

BTW, the product you linked is just polish - it won't work to do the correction necessary after painting/wet sanding. Meguires do make a couple of fairly decent compounds.
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PostPosted: Mon Apr 10, 2023 8:41 am
With the clear 2k practice on something first,You need light at just the right angle so you can see it flow out.You dont spray on off trigger like you normally do with rattle cans,nice slow pace, back and forth with lots of overlap and it lays down pretty good.

Once a can gets half to 3/8 empty dont start another coat with it,less pressure it will splatter.Buy extra cans and start ea coat with a new one if doing a door or fender etc.



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PostPosted: Mon Apr 10, 2023 10:28 am
NFT5 wrote:
sdowney717 wrote:sanding color coat is bad idea?


Very bad.

sdowney717 wrote:So no feathering of edges?


Blend edges by releasing trigger while moving gun.

sdowney717 wrote:I then used a medium compound on it to smooth it some.


Also a very bad idea. The compound will likely result in fisheyes when you spray the clear.

Basecoat is intended to be covered with clearcoat as soon as it has flashed off, so 15-30 minutes, depending on ambient temperature and thickness of the base.

At this stage the safest thing you can do is clean the panel using Prepsol then very lightly, but evenly, scuff with grey Scotchbrite. Flash for 15-30 minutes then tack the whole panel. Apply a coat or two of base, not heavy, over the repair area, blending out around the edges. Allow to flash then clear the whole panel.

Use 2K clear, which is available in spray cans. Allow that at least 24 hours to cure and harden then denib, wet sand if necessary and compound on your buff, followed by polish.

BTW, the product you linked is just polish - it won't work to do the correction necessary after painting/wet sanding. Meguires do make a couple of fairly decent compounds.

I was using a stove top polish compound, it is white and not greasy
I used the machine with a yellow foam pad and the stove top polish.

But I also have this which I had lost, but found again. Meguiars ultimate compound.
https://www.amazon.com/dp/B06W5HCZ9M?ps ... ct_details

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PostPosted: Mon Apr 10, 2023 10:50 am
You are missing the main point. You don't sand or polish base coat.

The repair you are attempting is called blending. There is a proper way to do it but using rattle cans isn't it.

In order to complete what you started, you will need to apply the base coat over the repair area and extend each coat a bit farther than the previous one. Then you need to cover the entire area (preferably the whole panel) with a clear coat as described above.
1968 Coronet R/T


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PostPosted: Mon Apr 10, 2023 11:41 am
'68 Coronet R/T wrote:You are missing the main point. You don't sand or polish base coat.

The repair you are attempting is called blending. There is a proper way to do it but using rattle cans isn't it.

In order to complete what you started, you will need to apply the base coat over the repair area and extend each coat a bit farther than the previous one. Then you need to cover the entire area (preferably the whole panel) with a clear coat as described above.


I am slowly figuring this out with the help here. I am used to sanding other kinds of paints to smooth it, which is where I had gone wrong. Actually, the Dupli-Color rattle cans do lay down pretty smoothly. I had also been thinking sanding as a way to key it for the gloss clear coat, get to adhere better.

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PostPosted: Mon Apr 10, 2023 4:39 pm
You don't need to prep base coat before clear is applied. The Technical Data sheet for your product will tell you how long before top coating.

The surrounding clear on the panel will need to be scuffed with a fine grey Scotchbright pad just to dull the surface. That will provide good adhesion for the new clear be applied.

NFT5 already covered this in his earlier post.
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