[tom_001]

Hello,

I'm hoping for some advice, I removed, repaired and sprayed my front bumper on my bm e46, half was rubbed down, primerd, base coat then metallic top coted, all good so far, I decided to lacquer the whole bumper so i rubbed down the new acrylic top coat and the original lacquer.
The whole bumper was given 3 coats of acrylic lacquer, now its fully hard and back on the car, hard to tell it was done.
However the all new paint is solid and as it should be but the other half that was preped original lacquer the new clear coat scratches off with a little force with my fingernail.

not is it only odd, but I think the only thing I can do is to remove the bumper again and completely rub down past the new and original lacquer, top coat and lacquer the entire bumper. (or pay some one to :s)

Any one got any clues to why the acrylic lacquer decided not to stick over the preped original lacquer? cheap dud lacquer? do they have dates on them?
maby not keyed well, whats the coarsest grade w&d that wont show through clear coat?

Many thanks tom.

[Duncan]

Hi Tom
There are so many different chemistries in paint that mixing old and new is always a dodgy business

Sometimes you get away with it ...

The only thing that will be certain is rub off all of the old paint and start again

[franky975]

Originally Posted by tom_001

Hello,

I'm hoping for some advice, I removed, repaired and sprayed my front bumper on my bm e46, half was rubbed down, primerd, base coat then metallic top coted, all good so far, I decided to lacquer the whole bumper so i rubbed down the new acrylic top coat and the original lacquer.
The whole bumper was given 3 coats of acrylic lacquer, now its fully hard and back on the car, hard to tell it was done.
However the all new paint is solid and as it should be but the other half that was preped original lacquer the new clear coat scratches off with a little force with my fingernail.

not is it only odd, but I think the only thing I can do is to remove the bumper again and completely rub down past the new and original lacquer, top coat and lacquer the entire bumper. (or pay some one to :s)

Any one got any clues to why the acrylic lacquer decided not to stick over the preped original lacquer? cheap dud lacquer? do they have dates on them?
maby not keyed well, whats the coarsest grade w&d that wont show through clear coat?

Many thanks tom.

Hi Tom.

I use 800wet and dry to prep the whole panel spray the base coat on it then when it is fully dried /apr.30min on room temp./ clearcoat the whole lot. Try to use something different lacquer.
Franky.

[Coley]

Hard to believe that you are spraying lacquer over enamel without it lifting like crazy.

Check with your paint supplier and see what he says to use after you strip the old finish off.

Flex additive in the color/clear coats is advisable.

[PhantomPholly]

Spraying is old-school.

Try this stuff.

[Duncan]

Originally Posted by PhantomPholly

Spraying is old-school.

Try this stuff.

Hi Phantom

That stuff looks awesome - have you tried it?

[mizlplix]

Many things cause what you describe. Mostly, not clean enough.

It should have been washed, Chemical wiped, wet sanded with 600#-1000#. applied sealer/primer, lightly sanded with 1000# shot then cleared.

Never use lacquer over enamel as was previously pointed out.....

Yes, mixing different paints is VERY chancey. That is why the sealer/primer coat between them.

Yes, resand all down to the original paint, start over clean.

Sorry, Miz

[PhantomPholly]

Originally Posted by Duncan

Hi Phantom

That stuff looks awesome - have you tried it?

Personally no, although I considered using some on my plane (to get an "American Flag" look). However, wraps are becoming more and more practical and are easier to get a professional finish with than in times past. Too, where weight is a consideration they are much more predictable.