Bird excrement surface etching
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Bird Excrement Consists of [: Uric acid, C5H4N4O3 [a diprotic acid, thus in strong alkali at high pH it forms the dually charged full urate ion, but at biological pH or in the presence of carbonic acid or carbonate ions it forms the singly charged hydrogen or acid urate ion as its pKa2 is greater than the pKa1 of carbonic acid] [1]
Water solubility
of uric acid and its alkali metal and alkaline earth salts is rather low
[:
the property of a solid, liquid, or gaseous chemical substance called solute to
dissolve in a solid, liquid, or gaseous solvent to form a homogeneous solution
of the solute in the solvent]
Cause -
the different types of food ingested by birds affect the composition and
quantity of droppings. Chemical aggression on the paint surface is caused by
strong organic acids acting for an extended period and exposed to high
temperatures and moisture (reactivity).
One of the most serious threats to a paint surface; it's not
only disgusting - it's a toxic hazard. Bird excrement contains unpleasant
fungi, including Histoplasma capsulatum and Cryptococcus neoformans as well as
bacteria, including Chlamydophila psittaci. Migratory birds, especially
seagulls are known to spread hard-to-treat infections as they can carry
antibiotic-resistant bacteria.
These are known to cause pneumonias as well as systemic
infections. Various forms of encephalitis are also associated with bird
droppings, so avoid direct skin contact.
Unlike mammals, birds don't urinate; their kidneys extract
nitrogenous wastes from the bloodstream, but instead of excreting it as urea
dissolved in urine, they excrete it in the form of uric acid. Uric acid, being
nearly water insoluble, exits a bird's body in the form of crystals that look
like a white paste. That's what those streaks of white paint-like substances
are that you so often see on the sides of buildings and splattered on vehicle
surfaces, which if left on the surface
and is then subjected to reactivity it will result in an indentation in the
surface (etching) around the periphery
Bird excrement is one of the most damaging environmental
pollutants as they relate to automobile paint as it comprises; Ammonia and
urine as white crystals of uric acid (pH 3.0 - 4.5) a small organic compound,
which is produced by the breakdown of protein during digestion, and is excreted
by reptiles and birds. Uric acid is also the end product of nitrogen catabolism
in birds Ammonia is a mixture of nitrogen gas and hydrogen gas; with moisture
as a catalyst it becomes Ammonium Hydroxide, which is caustic.
Reactivity
[: acceleration of a chemical reaction by a catalyst]
Be cognizant that an acid is inert until
it comes into contact with moisture; any chemical attacking a surface, temperature will dictate
reactivity (acceleration of a chemical reaction by a catalyst [moisture and heat]. The more heat and
moisture that is present (in the form of high humidity, dew and etc) the more
aggressive the acid becomes.
Then you have; an acid + water +oxygen + ozone all of which
forms an acidic oxygen molecule that causes a concave indentation (acid
etching) to the paint surface it should be noted that until this acid is
neutralised subsequent moisture and heat will reactivate the acid and allow
further damage, as acid requires an alkaline to neutralize it
This will cause surface etching (an indentation
of the clear coat) so they should be removed without delay. In this case, paint
care not only serves aesthetics, but also helps preserve the vehicles. At lower temperatures (> 40.oF
or less) there’s no reactivity and therefore little or no etching.
As urethane clear coat paint is heated by ultra violet
radiation, it both softens and expands that same heat dries and solidifies the
bird excrement on the paint surface. Once the paint protection product
fractures (reaches its melting point) it is no longer able to withstand the
acids, which allows them to quickly penetrate the paint matrix.
This will cause surface etching, so they should be removed
without delay. In this case, paint care not only serves aesthetics, but also
helps preserve the vehicles. The longer the excrement remains on the paint
surface, and the higher the temperatures, the harder the dried deposit will be,
and the greater the propensity for paint surface damage
At lower temperatures (> 40.oF or less) there’s no reactivity
and therefore little or no surface etching
Catalyzed
hydrolytic degradation
Definition [:
the damage can range from paint discoloration to the film dissolving
completely. Bubbling, swelling and etching are typical phenomena]
Be cognizant that there are no polymers or waxes that are
acid-proof; they all only offer short-term resistance. The most pertinent
factor is to have a layer of (sacrificial) protection between the acid and your
paint surface. The second is to ensure that is removed and any residue is
neutralized as soon as possible. For added protection apply an organic wax over
the polymer sealant, as this acts as a sacrificial barrier and by washing the
vehicles paint surface plus the reapplication of the sacrificial barrier on a
regular basis.
Paint protection
Most natural contaminants are hydrophilic in nature including
bird poop. Automotive clear coats are generally based on urethanes, acrylics,
melamine’s, silanes, etc. which are hydrophobic and repel water and other
contaminants initially. However as the paint surface gets oxidized
environmental contaminants will bond to the surface. Polishing the paint
surface removes the oxidized layer and makes the paint surface hydrophobic
again for a short period of time.
Waxes (Carnauba and synthetic) as well as polymer sealants might
not offer much protection against bird droppings, they will make the surface
hydrophobic and minimize bonding of the contaminants to paint. This can help
reduce the damage from bird poop and make removal of the contaminants much
easier. Besides being very acidic, bird
droppings contain enzymes which can break down C-C linkages in automotive paint
(See
also this article “.Nanotechnology and other Coatings”)
Note:
some of the newer coating products rely on a configuration
Si-C (SiO2) bond, which are far more
resistant to enzymes than the C-C (copolymer) configuration used
in polymer sealants. Due to the applied coating thickness they are more resistant to the acids found in excrement than a
polymer sealant. Notwithstanding, these acids should be removed as soon as
possible. However,
if there is any staining left behind, do not polish it, as this will remove the
coating, since the stains are not a sign of etching and usually they are on top
of Opti-Coat and can break down/disappear after a few days.
Food
Sources
Their main food source in summer is mostly insects and seeds, in
the winter/ spring it’s berries, which are very acidic, and if left for any
length of time the will cause the porous clear coat to occlude (a
non-transparent ‘clouded’ area) or may cause etching (a depression in the paint
or glass surfaces)
Birds use gravel to help digest their food, predatory birds
(owls, hawks, etc hunt and kill mice and small animals, so ground light weight
bone fragments, sand and grit are some of the major components, which can cause
scratching.
Excrement
removal
Avoid using a quick detailer (QD) spray or a sealant to flush
residue, as they usually contain either carnauba wax or polymers, which will
seal in the acid and not allow it to dissipate.
Take your time and be careful with its removal, these acids
should be removed as quickly as possible. If the affected paintwork is not
neutralized any remaining acid residue will be reactivated by moisture and
heat.
•
Limonene (citrus-based) cleaner (P21S Total Auto Wash)
will both emulsify and neutralize the acid or use an alkaline rinse of baking
soda and water as soon as is practical is highly recommended.
•
1:1 solution Isopropyl alcohol (IPA) and distilled water. The
alcohol content acts as a drying agent, which will extract the acid, then
thoroughly flush with water to rinse away any grit or sand, etc or use
detailers clay to encapsulate it, re-spray the area let it react for 2-3
minutes and wipe dry.
•
Glass cleaner (do not use one that contains ammonia; as it acts
as an acid accelerant
•
Gel alcohol hand cleaner (Purell
®) Place a small amount on to a first aid gauze pad
and apply to effected area this will help it stay in place during the necessary
react time. The alcohol content acts as a drying agent, which will extract the
acid, then thoroughly flush with water to rinse away any grit or sand, etc or
use detailers clay to encapsulate it, re-spray the area let it react for 2-3
minutes and wipe dry.
An automobile paint system is porous; when you add moisture and
heat to an acidic substance it will erode the paint system very quickly; as the
heat opens microscopic fissures in the clear coat allowing ingress, the water
provides a carrier system for the acid, and heat acts as a catalyst
(reactivity) each time water is reintroduced the acid will be reactivated and
erode the paint matrix
Type
of Surface Damage
Identify the type of damage (Type I Surface staining
or Type II Surface etching (a concave
indentation) Ultra violet (UV) radiation (heat) causes the urethane clear coat
to expand allowing contaminates to permeate; the same heat greatly accelerates
the corrosive abilities (reactivity) of the acid, for these reasons any acid or
alkali should be neutralized (See
Acid / Alkali Neutralization)
Verification of the type of surface condition can be diagnosed
through the use of a 30X magnifier. Any acid should be removed from the paint
surface ASAP; proceed by using the least abrasive products first
Type I
[is an off-white non-transparent
‘clouded’ stain] that if left for any length of
time that will cause the porous clear coat to occlude (become non-transparent)
this is usually inherent with a light surface stain.
The paint will usually become stained as soon as the excrement
has dried. Providing it is removed quickly and hasn't been subjected to
reactivity (moisture and heat) this can usually be removed easily, especially
if there is a sacrificial coat of wax on the paint
1. Use a chemical
paint surface cleaner (Z-PC Fusion Dual Action Paint Cleaner) to remove surface
stains
2.
Use ValuGuard Acid Neutraliser (Step I) - diluted 1:8
neutralizes acids deposited on the paint surface and in the pores of the paint
3.
Try to dissolve the surface/etched deposits trying one or more
of the following;
a)
Use a 2:1 or stronger solution of distilled water/distilled
white vinegar (Acetic acid)
b)
Try a 2:1 solution of distilled water/Isopropyl Alcohol (adjust
ratio as required)
c)
Or equal parts distilled water/distilled white vinegar/Isopropyl
alcohol.
4. Clean the effected
surface with Klasse All-In-One or Zaino Z-PC Fusion Dual Action Paint Cleaner
Type II [is a mark with surface etching (a concave indentation) around its
perimeter] this is usually the result of a
stain that has been on the surface for a while and has been subjected to
reactivity (the addition of moisture and heat), which produces an acid that
etches the paint surface. After the excrement has dried the acid will begin to
corrode the paint surface, this corrosion accelerates once moisture and heat
(reactivity) is added, it may take minutes or up to an hour for it to etch the
paint surface
1. Use a chemical
paint surface cleaner (Z-PC Fusion Dual Action Paint Cleaner) to remove surface
stains
2.
Use ValuGuard Acid Neutraliser (Step I) - diluted 1:8
neutralizes acids deposited on the paint surface and in the pores of the paint
3.
Use detailing clay to remove any `hard' surface granules
4.
Use a machine polish (Optimum Polish or Optimum Compound) and a
cutting (LC White, Orange or Yellow) foam pad (speed # 4- 5.0) to level the
surface
5.
For PPG CeramiClear™ Clear Coat or other hard clear coats
substitute Menzerna for machine polish; PO 203 S - Power Finish
6.
Use the least aggressive polish/foam pad first, if this doesn’t
remove the problem step-up to a more aggressive polish / foam pad set-up
7.
Wet-sand with 2000, 2500 or 3000 grit finishing paper and polish
with a finishing polish
8. Apply a paint
protection
Do not scrub hardened/dried excrement residue, birds use gravel
to help digest their food so grit and sand are some of the major components,
which can cause scratching as it is very abrasive and will scratch the paint
surface. Once it softened (re-liquefied) it enables their removal with less
likelihood of damage to the paint surface Do not use on a hot paint surface
(soon after driving) as this will cause streaking
Use a solution of Optimum no-rinse (ONR) diluted 1:20 /
distilled water in a fine mist spray bottle) and allow to react time as this
will soften debris and allow it to be removed with a mesh covered bug sponge
Protection
Klasse, Jeff Werkstatt or Duragloss #105 Total Performance Polish are all acid-based, acrylic polymer or
polyethylene-acrylic o they are more resistant to acidic pollutants (acid rain,
bird excrement, and etc) there is no product wax, polymer or nano coating,
including CeramiClear that is acid-proof. For added protection apply an organic
wax over the polymer sealant as this sacrificial barrier and by washing the
vehicles paint surface on a regular basis.
Optimum
Opti-Coat™ is based on a resin pre-polymer
that uses
a configuration of (Si 14) (SiO2 -silica)
bond,
which are far more resistant to enzymes than the C-C configuration used in polymer
sealants. As a consequent it is more resistant to the acids found in bird excrement.
It forms ceramic bonds at very high temperatures and
will not be damaged by extreme heat and therefore resists oxidation.
Opti-Coat has better resistance
to chemicals (acid), scratches and release properties than other automotive
coating currently in use. This coating
has a 2-4 µ (microns) applied thickness and a hardness of 9H (Pencil
Hardness) when fully cross-linked and provides a semi-permanent coating like a
regular clear coat lasts indefinitely unless it is removed by polishing,
sanding, or paint
Far beyond washing, cleaning and detailing your automobile
inside and out, the best preservative action you can take is to cover the car
with a car cover. It provides the best protection against industrial fallout
(IFO) dust, dirt; ultra violet (UV) and infrared (IR) radiation; bird excrement
and windblown debris (See also Car Cover Section)
Aves
bomb First Aid Kit- use a 1:20 Optimum
No-Rinse (ONR) / distilled water solution in a fine
mist spray bottle. The surfactants it contains encapsulate and trap bird and
insect excrement, dry surface dust, or light dirt particles making them
virtually non-abrasive and it can be used without causing scratches (check
contents periodically as heat will evaporate the contents if stored in the
car’s trunk)..
Apply with a long nap micro fibre towel using very little
surface pressure, dusting with long strokes in one direction only. For stubborn
stains, soak the micro fibre towel and allow it to remain in n place for a few
minutes and then wipe away the debris.
Caution - Dispose of any
towels or wipes used to remove bird droppings immediately and thoroughly wash
your hands, as bird lime can harbour diseases
Avoid using a QD spray to flush residue, as they contain either
carnauba wax or polymer sealants, which will seal the acid and not allow it to
dissipate. Using an alkaline rinse of baking soda and water (to neutralize the
acid) as soon as is practical is highly recommended, if the affected paintwork
is not neutralized any remaining acid residue will be reactivated (heat and
moisture). If the paint or glass surface has been etched the surface can be
levelled with a suitable polish (Zaino
PC Fusion Dual Action Paint Cleanser) and then
apply a paint protection.
Excrement
Removal
Be cognizant that the longer the deposit remains on the bodywork
and the higher the ambient temperatures, the harder the dried deposit will be,
and the greater the propensity for paint damage. This type of damage can only
be prevented by motorists remaining vigilant and removing the deposit as this
pollutant can have a serious negative impact on your paint finish if not
removed safely and expediently. Also be aware there are no polymers, nanotechnology
coatings or waxes that are acid-proof; they all only offer short-term
resistance although they will make them easier to remove
Use the least
abrasive product first-
1. Use a paint surface
cleaner (Z-PC Fusion Dual Action Paint Cleaner)
2.
Try to dissolve the alkaline-based, surface/etched mineral water
deposits try one or more of the following;
a)
Use a 2:1 or stronger solution of distilled water/distilled
white vinegar (Acetic acid)
b)
Try a 2:1 solution of distilled water/Isopropyl Alcohol (adjust
ratio as required)
c)
Or equal parts distilled water/distilled white vinegar/Isopropyl
alcohol.
3.
Clean the effected surface with Klasse All-In-One or Zaino
Z-PC Fusion Dual Action Paint Cleaner
4.
Use detailing clay to remove any 'hard' surface granules
5.
Use a machine polish (Optimum
Polish or Compound) and a cutting (LC White, Orange or Yellow) foam pad
(speed # 4- 5.0) to level the surface
6.
For CeramiClear or other hard clear coats substitute Menzerna
for machine polish; Super Intensive Polish / Nano Polish (105FF) or Final
Finish Polish (106FA)
7.
Use the least aggressive polish/foam pad first, if this doesn’t
remove the problem step-up to a more aggressive polish / foam pad set-up
8. Wet-sand with 2000,
2500 or 3000 grit finishing paper
Bibliography
1.
Alma Heritage Science – Uric acid
from bird droppings
2.
Effects of Environmental Conditions
on Degradation of Automotive Coatings, a paper by Mohsen Mohseni, Bahram
Ramezanzadeh and Hossain Yari
3.
Bond Disassociation Energies in
Organosilicon Compounds, a paper by Robin Walsh
4.
Polymer Basics DoITPoMS - University
of Cambridge
Relevant
Articles
1.
“Acid
/ Alkali Neutralization” - http://www.autopia.org/forum/autopia-detailing-wiki/140032-acid-base-alkali-neutralization.html#post1489787
2.
“Detailer’s
Clay” - http://www.autopia.org/forum/autopia-detailing-wiki/137637-detailers-clay.html#post1459468
3.
“Environmental Damage” - http://www.autopia.org/forum/car-detailing/136393-environmental-damage.html#
4.
“Nanoskin
Surface Prep Towel” - http://www.autopia.org/forum/autopia-detailing-wiki/141207-nanoskin-surface-prep-towel.html
5. “ValuGard
Paint Decontamination System” - http://www.autopia.org/forum/autopia-detailing-wiki/141242-valugard-paint-decontamination-system.html
6.
“What
will decontamination remove that washing / clay will not? “ - http://www.autopia.org/forum/guide-detailing/136545-what-will-decontamination-remove-washing-will-not.html
7.
“Why
use a wax on top of a polymer sealant?” - http://www.autopia.org/forum/autopia-detailing-wiki/136406-why-use-wax-top-polymer-sealant.html
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