Originally Posted by Maestro
I have number of questions which all relate to acid bird poop.
I have a Black Sapphire car and it has become a target for high flying Geese that I have in the area. The damn things seem to be targeting the car, however I degress.
I have read a number of posting on the subject and there are a number of opinions of how to deal with the mess the bird left behind. In my case the hood got hit and the car was sitting out in the sun for a while after it happen. I cleaned it off with water and noice it left a mark. I tried a few simple things with no luck. So I got a bit agressive hit it with rubbing compond and polish and it seemed to work, but a few days later the marks showed up again. Recently, I had the car in for servicing and asked the dealer to take a wack at it and they tried with no luck. They said the clear coat is etched.
The interesting thing is I have other cars which are not black but have clear coat and they have been hit and I did not clear off right away and never see this problem on them, and one is a dark red and it shows everything.
So my question is the only thing left to do is wet color sand with 1500 or 2000 grit and buff it all out. Or is there something else I can do, I really do not want to wet sand the car, I am not afraid to do this, since I use to restore cars and spend hundred of hours color sanding cars.
I have some other questions, I read it was a good ideal to waste the poop off with a mix of water and alcohol or vinegar, what exaclt does this do, and should I keep a bottle of this in car since the cars keeps getting hit.
Next thing is the clay block I have read about, again what exactly does this do for the finish and how does it remove the marks in the paint.
Sorry for the slow reply, I'm not sure how I missed your post. As far as the bird droppings, the way I treat them is the following. I remove the actual bird droppings with a mixture of Isopropyl Alcohol and Water... then I try to neutralize the mark with a mix of baking soda and water. You're goal is to neutralize the acid in the droppings which usually occurs from what the birds ate that day, berries, worms, etc. I've seen some bird droppings sit on paint for months with no etching (thank that birds diet) and some that etch within minutes of bombing, it really is just the luck of the draw, or splat.
After that, then you have to deal with the etching. Chances are if the compound made it go away then it came back, the compound used had some sort of fillers in it and you'll need to resort to something more aggressive. When using the compound (if you use it again) wipe it off with the ISA / Water to reveal the true clear coat without and fillers so you can more accurately decide how well the compounding did for you.
If polishing fails, the final step before a repaint would be to wet sand as you stated.
A clay bar will properly prep the surface and remove stubborn contamination that is not removed with a normal wash and dry. Here is a guide I've written about understanding clay bars
and how-to use a clay bar properly
Let me know how you make out and if you'd like me to go in more depth with anything.
Originally Posted by sapperelite
Just wanted to let you know I got the items you sent in near record time. Thanks for the quick service. A second question for anyone with experience, I put three small scratches, about 1-2mm long on my front spoiler. I can't get the whole thing repainted but cannot stand to see her with a scratch. I bought the BMW dealer touch-up kit and would like some advice on application. Thanks,
AJ, thanks for your positive feedback and your support! I'm excited to hear about your results using the products.
This is how I handle touch ups in a quick and dirty guide:
Apply the touch up paint liberally, you want to get that ugly blob effect. Let it cure for a few days. Come back to it and wet sand the blob down starting with around 1500 grit and working your way up to 2000, 2500, 3000 (whatever the highest you can get a hold of). After wet sanding you'll want to follow up with polishing stages to remove the wet sanding marks (this is why I recommend going as high as you can so it is easier to remove the wet sanding marks). When you are done polishing be sure to protect the paint.
- Right in the middle has a more in depth writeup on repairing paint scratches, which I initially learned from actually. It does a good job going over each step.
If you have any questions after reading that, let me know I'd be happy to clarify anything for you.