Collision Repair - Reducing Air Emissions 12-1 (a) Air Emissions from Autobody Repair Activities n Two basic kinds of air emmissions –Volatile Organic Compounds (VOCs) –Particulate (solids) n Volatile Organic Compounds (VOCs) –Volatile means the compounds “evaporate rapidly at a low air temperature”. –VOCs are chemicals, such as paint thinner, that evaporate rapidly

Collision Repair - Reducing Air Emissions 12-1 (a) Air Emissions from Autobody Repair Activities –VOCs contribute to the formation of smog in the lower atmosphere. –Material Safety Data Sheet will indicate a product’s VOC content. n Particulate –Solid part of paint –Contains the binder, pigments, and other additives.

Collision Repair - Reducing Air Emissions 12-1 (a) Air Emissions from Autobody Repair Activities –Some paint particulates are easy to see in the air, while others are not. –Nonetheless, all particulates decrease the air quality of our environment.

Collision Repair - Reducing Air Emissions 12-2 (a) Factors Affecting Air Emissions n Paint Booths –Paint booths control particulates »If equipped with paint arrestors (exhaust filters) »If used with a ventilation system n Can filter incoming air and remove dust that can ruin a finish. n Transfer Efficiency –Improved transfer efficiency »Less paint waste

Collision Repair - Reducing Air Emissions 12-2 (b) Factors Affecting Air Emissions »Less overspray »Lower air emissions. n Improve spraying techniques n Using equipment that is capable of a higher transfer efficiency. n Closed Solvent Storage Containers –Reduce evaporation –Keep used solvent-soaked rags in closed fire- proof waste container.

Collision Repair - Reducing Air Emissions 12-2 (c) Factors Affecting Air Emissions n Sanding/Blasting –Dust is potentially hazardous because it is contaminated with paint. –Use portable sandblasters with a vacuum attachment. »Keeps the air in the shop cleaner. »Worker exposure to dust reduced »Less dust reaches the outdoor air where it can cause pollution problems.

Collision Repair - Reducing Air Emissions 12-2 (d) Factors Affecting Air Emissions n Choice of Coating Materials –Choose low VOC, high solids surface coating materials. » VOC content is normally listed on Material Safety Data Sheets (MSDSs).

Collision Repair - Reducing Air Emissions 12-3 (a) Reducing Air Emissions From Autobody Repair Activities n Prep Coats –Use versatile products such as epoxy primers or self-etching primers. »May alleviate the need for additional surface coating operations –If these products are not acceptable -- use a wash-primer or metal conditioner conversion coating system.

Collision Repair - Reducing Air Emissions 12-3 (b) Reducing Air Emissions From Autobody Repair Activities n Primer-Surfacer –Minimize the number of coats applied. –Ensure that all major body imperfections are removed prior to priming operations (i.e. do not use a primer as a body filler.) –Use a primer gun with correct fluid tip/air cap combinations for each type of primer-surfacer. –If curing time of waterborne products is too long, consider using versatile urethane primers.

Collision Repair - Reducing Air Emissions 12-3 (c) Reducing Air Emissions From Autobody Repair Activities –When using a clear sealer, make sure the primer-surfacer is a color can be covered with the desired topcoat. »With transparent topcoats, the color of the undercoat may affect the color match of the topcoat. n Primer-Sealers –Use low VOC urethane primer-sealers as an alternative when possible.

Collision Repair - Reducing Air Emissions 12-3 (d) Reducing Air Emissions From Autobody Repair Activities –Choose primer-sealer in a color that is easily covered with the desired topcoat, or choose a tintable primer-sealer and tint it to an easily- covered color shade. n Sealers –Choose a sealer appropriate for each specific job. –If filling capabilities are required, use a primer- sealer in place of a sealer.

Collision Repair - Reducing Air Emissions 12-3 (e) Reducing Air Emissions From Autobody Repair Activities –Choose a primer-sealer of a color that can be easily covered with the coating to be sprayed, or choose a tintable primer-sealer. n Topcoats –Mix color coats in-house, making certain the formula for the proper shade of the specific color code is used. »Will help avoid the need for blending the finish to achieve a satisfactory color match.

Collision Repair - Reducing Air Emissions 12-3 (f) Reducing Air Emissions From Autobody Repair Activities –Keep good records of paint match information, including spray-out cards and detailed notes. –Use record keeping to help determine how much material should be mixed for the job. –Avoid the use of lacquer-based topcoats. –Choose low VOC topcoats that require fewer than three coats to achieve adequate coverage (polyurethane or urethane).

Collision Repair - Reducing Air Emissions 12-3 (g) Reducing Air Emissions From Autobody Repair Activities –Apply only the number of coats needed to achieve a quality finish. –Use high solids/low VOC clears to topcoat color coats. –Keep the addition of paint additives to a minimum.