this is really why bird dropings are harmful

[friendly_jacek]

Corrosive properties in bird droppings are not to blame for damage to your car’s paint job, according to UK car care product manufacturer Autoglym.
Autoglym researchers studied the process and determined exactly how the damage is caused.
In direct sunlight and in warm conditions, paint lacquer heats up, softens and expands. At the same time, heat bakes the droppings onto the surface, making them hard and crusted.
When the paint lacquer later cools and contracts, it molds to the uneven under-surface of the hardened deposit.
The result is an imperfect, textured paint surface that appears dulled compared with the unaffected paint.
from: Bird poo paint damage explained - how to protect your car |#CarAdvice (http://www.caradvice.com.au/117729/bird-poo-paint-damage-explained-how-to-protect-your-car/)

The explanation totally makes sense as uric acid is very weak and unlikely to be harmful chemically. But, I don't see how any type of wax/coating can protect from dried droppings and temp cycling of paint. They can make it easier to clean though when fresh.

[SYMAWD]

After just 4 hours on my car, look what happened. No etching, but right through the sealant.
http://i1014.photobucket.com/albums/af270/SYMAWD/IMAG1673_zpsba1d5dc8.jpg (http://s1014.photobucket.com/user/SYMAWD/media/IMAG1673_zpsba1d5dc8.jpg.html)

[BillE]

Yips! What was that bird eating?!?

I've noticed at different times of the year, the damage from bird poop is more corrosive than others. Wonder if it's from what they eat, more or less water in their diet, ETC.?

Bill

[vet]

I don't know for a fact, but I've heard that the acid from berries that birds eat have a lot to do with it.

[Rayner]

I've heard this before and makes perfect sense to me as a decorator as I've seen paint expand and contract many times so the bird poop would act as a clamp I guess.

I suppose the lsp could stop it from clamping down so much possibly?

[FUNX650]

Quote:
Corrosive properties in bird droppings are not to blame for damage to your car’s paint job, according to UK car care product manufacturer Autoglym.
Autoglym researchers studied the process and determined exactly how the damage is caused.
In direct sunlight and in warm conditions, paint lacquer heats up, softens and expands. At the same time, heat bakes the droppings onto the surface, making them hard and crusted.
When the paint lacquer later cools and contracts, it molds to the uneven under-surface of the hardened deposit.
The result is an imperfect, textured paint surface that appears dulled compared with the unaffected paint.
I ask:
-Is a modern-day BC/CC paint system: "lacquer paint"?
-Will modern-day BC/CC paint systems heat-up and expand to the same extent as, say:
A lacquer paint system allegedly does?



The explanation totally makes sense as uric acid is very weak and unlikely to be harmful chemically.

Surely you're not contending that "weak acids" are not going to be chemically harmful
to auto-paint from just this AutoGlym newsflash. Are you?



But, I don't see how any type of wax/coating can protect from dried droppings and temp cycling of paint.
They can make it easier to clean though when fresh.
Yes!...There are certain LSP's that are "known" to provide a little longer of a time-frame
to remove bird-poo...But whether it's acidic, or not, it's gotta come off ASAP!

"Acrylic LSP's", such as AutoGlym's, is one of the better known: "delayers-in-bird poo-removal"...in some parts of the World.
Then there's Klasse, Duragloss #105, Jeff Werkstatt, Zaino, etc. that are better known "acrylics" in other parts of the World.

:)

Bob

[PiPUK]

This is definitely an interesting topic. I certainly would not be able to definitively state what the mechanism is for the damage caused. A couple of thoughts if this process were accurate:

1) This would not apply simply to bird excrement. Think about metallic fallout, if the surrounding paint were to 'soften' then the metallic fallout would likewise be 'etched' into the paint.

2) What difference do coatings really make? I suspect that they are going to be sacrificial here. Certainly acrylic or siloxane coatings will be etched, the difference will be that the coating can be removed and leave the good paint. But what of the more permanent (non stripped by chemical means) coatings? I don't want a marketing man to answer this, if you haven't got real world data, we will know you are making it up! The coatings are hard but no one takes about thermal properties. Yes, they might stay stable, but they will be thermoplastic to some extent so will likely suffer the same potential issue highlighted in this thread.

Interesting.