Strange mark on paintwork

Ringmaster · 23-03-19, 05:15 PM

Hello folks,

My old uncle stopped using the bonnet bra he had for his E46. Instead he placed a couple of strips of clear masking tape over each other, horizontally across the front of his bonnet, between grille and BMW badge.

It was on there nearly a fortnight and he's had a job peeling it off. It's left behind 3 feint dark horizontal lines and I've tried polishing and using cutting compound to no avail. They are barely visible on the silver metallic paint from certain angles.

What could have caused it and is there anything I could try, short of a re-spray?

I suspect trapped moisture played a part and wonder if over time the lines will go?

Sandro · 23-03-19, 09:09 PM

probably sticker glue reacted or "eat" the clear coat. Seen it.
Try very easy rub with wet P2000 good quality sandpaper (3M) and polish it with. If that does not help it has to be painted again.

Isimmo · 23-03-19, 10:03 PM

Quote:

Originally Posted by Sandro

probably sticker glue reacted or "eat" the clear coat. Seen it.
Try very easy rub with wet P2000 good quality sandpaper (3M) and polish it with. If that does not help it has to be painted again.

100% this. It’s the solvent in the adhesive reacting with the clear coat...

Ringmaster · 24-03-19, 07:01 PM

Thanks fellas, I'll have a go when I get some of the 3M paper.

The clear coat is perfectly smooth to the touch.

It is best to apply the paper in a circular motion or along the lines?.....

Sandro · 24-03-19, 09:25 PM

Quote:

Originally Posted by Ringmaster

Thanks fellas, I'll have a go when I get some of the 3M paper.

The clear coat is perfectly smooth to the touch.

It is best to apply the paper in a circular motion or along the lines?.....

Circular only. And don't apply much pressure. Use with water. And You'll need polishing compound.

Isimmo · 24-03-19, 10:03 PM

Quote:

Originally Posted by Sandro

Circular only. And don't apply much pressure. Use with water. And You'll need polishing compound.

Once again, agree, too wet isn’t an issue. To dry = fook-up....

Davids · 25-03-19, 12:16 AM

You can dry sand with a da and 1500 or 2000, or even finer, however if you have never done colour sanding before, which I doubt given the asking please leave to to someone who has. If this is factory clear coat then the build will be minimum and you can easily go thru to the base coat.

If you are new to this process just try some G3 by hand before wet or dry sanding. Take it easy as G3 will still cut thru on edges, if fact it might pay just to try a finer cut first and see how you get on. Not sure what compound you may have tried

Ringmaster · 25-03-19, 08:20 AM

I'll be very careful. I guess I'll soon see if any benefit is happening.

I've been using G3 Paint Renovator.

I suspect a re-spray will be inevitable. There are quite a few stone chips thereabouts, hence how we find ourselves in this boat......

Thanks chaps......

Ringmaster · 28-03-19, 07:26 PM

Chaps,

Tried the 3M paper today without success, so looks like a respray.

The stain seems to have gone through the clear coat completely. Fortunately the lines are not too obvious without close inspection.... Thanks for the advice though fellas.....

Ringmaster · 13-04-19, 11:47 PM

Fellas,

Since I last posted about this, I've noticed an ever so slight improvement in the appearance of the lines... Maybe it just needs for UV exposure to resolve itself...

23-03-19, 09:09 PM	#2
Sandro Grown up member Join Date: Feb 2011 Location: Chelmsford Posts: 651	probably sticker glue reacted or "eat" the clear coat. Seen it. Try very easy rub with wet P2000 good quality sandpaper (3M) and polish it with. If that does not help it has to be painted again.

24-03-19, 07:01 PM	#4
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	Thanks fellas, I'll have a go when I get some of the 3M paper. The clear coat is perfectly smooth to the touch. It is best to apply the paper in a circular motion or along the lines?.....

25-03-19, 12:16 AM	#7
Davids 4 ring whore! Join Date: Jan 2017 Posts: 3,124	You can dry sand with a da and 1500 or 2000, or even finer, however if you have never done colour sanding before, which I doubt given the asking please leave to to someone who has. If this is factory clear coat then the build will be minimum and you can easily go thru to the base coat. If you are new to this process just try some G3 by hand before wet or dry sanding. Take it easy as G3 will still cut thru on edges, if fact it might pay just to try a finer cut first and see how you get on. Not sure what compound you may have tried

25-03-19, 08:20 AM	#8
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	I'll be very careful. I guess I'll soon see if any benefit is happening. I've been using G3 Paint Renovator. I suspect a re-spray will be inevitable. There are quite a few stone chips thereabouts, hence how we find ourselves in this boat...... Thanks chaps......

28-03-19, 07:26 PM	#9
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	Chaps, Tried the 3M paper today without success, so looks like a respray. The stain seems to have gone through the clear coat completely. Fortunately the lines are not too obvious without close inspection.... Thanks for the advice though fellas.....

13-04-19, 11:47 PM	#10
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	Fellas, Since I last posted about this, I've noticed an ever so slight improvement in the appearance of the lines... Maybe it just needs for UV exposure to resolve itself...