Bird Excrement (Safe removal )

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Bird Excrement:

(Or insect excrement like Gypsy moth, June bug, Honeybees, etc) contain highly acidic concentrates (uric acid (pH 3.0-4.5) which 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) Heat (vehicle paint temperature of 90oF+) creates a very aggressive reactivity of the acids that are present, which causes surface etching, so they should be removed without delay, at lower temperatures (40oF or less) there s no reactivity and therefore little or no etching.

No wax or polymer sealant can provide a permanent shield against acidic bird excrement (Collinite 845 Insulator Wax is probably the most durable Carnauba wax product) but this may only provide enough of a barrier to enable it to be removed quickly before causing too much damage to the paint film surface

Birds use gravel to help digest their food so grit and sand are some of the major components, which can cause scratching. Insect honeydew (sometimes mistaken for tree resin) excreted by aphids or scale insects that infest the leaves and branches is also acidic. Residue should be removed (see below) as soon as possible as it could compromise the clear coat.

Take your time and be careful with its removal, these acids should be removed and/or neutralized as quickly as possible. Using an IPA (isopropyl alcohol) no ammonia based (ammonia acts as an acid accelerant) glass cleaner or a 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 dwell 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 dwell for 2-3 minutes and wipe dry.

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 .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).

Do not scrub hardened/dried excrement residue as it is very abrasive and will scratch the paint surface, once they are softened (re-liquefied) it enables their removal with less likelihood of damage to the paint surface

• If the paint can be rectified by chemical means (e.g. acid, concrete, water spotting, etc.) then this is the answer; not abrasive cleaning. Using the correct chemical cleaners will dissolve the contaminants rather than abrading the paint.

• The paint system is porous; when you add water and heat to an acidic substance it will erode the paint system very quickly (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 each time water is reintroduced the acid will be reactivated).

The paint surface should be periodically neutralized / decontaminated (See also Reactivity)

Product specific - Automotive International - A, B C Decontamination / Neutralization wash system

Information source

• "Automotive Detailing Inside & Out, A Knowledge Base for the Perfectionist" – by Jon Miller