WELCOME

1. SURFACE COATINGS - METAL CUSTOMIZED ENVIRONMENTAL TRAINING WELCOME

2. INSTRUCTOR Insert Instructor Name Here

3. OBJECTIVES • Discuss Hazardous Materials Used in Metal Coating and Coating Removal. • Define VOC and Explain How to Calculate VOC Content. • Discuss the Types of Metal Coatings. • Discuss Transfer Efficiency. • Give an Overview of Application Technology. • Give an Overview of Coating Removal Technology. • Discuss Logs and Recordkeeping. • Recommend Inspection Items. • Discuss Use of Contractors.

4. GOALS • Understand the Hazardous Materials Used in Metal Coating and Coating Removal. • Understand VOC and Understand How to Calculate VOC Content. • Be Familiar With the Types of Metal Coatings. • Understand How to Improve Transfer Efficiency. • Understand Some of the New Available Application Technologies. • Understand Some of the New Available Coating Removal Technologies. • Be Familiar With Required Logs and Records.

5. BACKGROUND • In 1998, 61,234 industries reported a total of 7.3 billion pounds of hazardous chemicals released to the air, land and water in the United States. • Fugitive Air Emissions, Water Emissions from Poorly Treated Rinsewater, and Solid Waste Generated from Coating and Coating Removal Operations can have a Detrimental Impact on Human Health and the Environment.

6. LEARNERS • Supervisors • Facility Engineers • Maintenance Personnel • Department Managers • Building Occupants • Process Specialists • Environmental and Safety Committees

7. OVERVIEW The goal of this course is to provide supervisors with the tools needed to help reduce hazardous waste from metal surface coating operations. It recommends practical, actions that can be carried out by facility management, maintenance personnel and building occupants. It also gives an overview of new technology in coating application and removal. The course will help you to integrate good surface coating management activities into your existing organization and identify which of your staff have the necessary skills to carry out those activities.

8. WHAT THIS COURSE DOES NOT DO The course is not intended to provide specific equipment recommendations for reducing pollution at your facility. These specialties required training beyond the intended scope of this course. Where this expertise is needed, outside assistance should be solicited.

9. Clean Water Act addresses wastewater effluent requirements. RCRA addresses hazardous waste used in metal finishing, including minimization Clean Air Act Amendments address harmful air emissions in coatings EPA’s Toxic Release Inventory (TRI) requires businesses to disclose toxic materials at facilities FEDERAL LAWS

10. Pertinent Regulations: 40 CFR Part E413 –The Effluent Guidelines and Standards for Electroplating 40 CFR Part 59 – National Volatile Organic Compound Emission Standards for Consumer and Commercial Products FEDERAL REGULATIONS

11. Without metal finishing, products made from metals would last only a fraction of their present life-span. Metal finishing alters the surface of metal products. Industries that use metal finishing in their manufacturing processes include: Automotive Electronics Aerospace Telecommunications Hardware Jewelry Heavy Equipment Appliances WHY FINISH METALS?

12. Of particular importance are those processes that use highly toxic or carcinogenic ingredients that are difficult to destroy or stabilize and dispose of in an environmentally sound manner. Some of these processes are: - Cadmium plating. - Cyanide-based plating, especially zinc, copper, brass, bronze and silver plating. - Chromium plating and conversion coatings based on hexavalent chromium compounds. - Lead and lead-in plating. - Numerous other processes. THE POLLUTION PROBLEM

13. The metals finishing industry is concerned with pollution and wastes generated by all processes but especially those generated by the use of four specific materials in finishing processes: the use of cadmium as a plating material, the use of chromium as a plating material, the use of cyanide-based electroplating solutions, the use of copper/formaldehyde-based electroless copper solutions. HAZARDOUS MATERIALS AND PROCESSES

14. Cadmium is a common plating material that has properties superior to other metal coatings in some applications. It displays excellent corrosion resistance and is valued for its natural lubricity or smoothness. It exhibits good corrosion resistance, and meets the salt-spray test requirements of the automotive industry. It can be soldered readily and is toxic to fungus and mold growth. In the past, numerous military specifications have specified the use of cadmium. The major cadmium complex used in electroplating baths is cadmium cyanide, or Cd(CN-24). CADMIUM

15. Sodium and potassium cyanide are used in electroplating bath formulations for the deposition of copper, zinc, cadmium, silver, gold, and alloys such as brass, bronze, and alballoy (copper-tin-zinc). Electroplating baths may also utilize cyanide compounds of the metal being plated, such as copper cyanide, potassium gold cyanide, or silver cyanide. In a well-designed wastewater treatment system, most cyanides can be destroyed through oxidation. Cyanides used in stripping solutions, especially those for stripping nickel, are similarly resistant to oxidation and typically must be disposed of in bulk at a high cost. CYANIDE SOLUTIONS

16. Electroless copper deposits are frequently used to apply a conductive base to non-conductive substrates such as plastics. A thin copper deposit provides a base for an additional decorative or functional coating of copper, nickel, etc. One important application is in the coating of printed circuit boards. Formaldehyde, a water pollutant and a suspected carcinogen, is used as the reducing agent in electroless copper baths. Caustic mists resulting from hydrogen evolution and air sparging in the baths present an additional hazard. COPPER/FORMALDEHYDE SOLUTIONS

17. Decorative chromium plating is almost always applied over a bright nickel plated deposit, which in turn can be easily deposited on steel, aluminum, plastic, copper alloys, and zinc die castings. Functional chromium plating is normally not applied over bright nickel plating, although in some cases, nickel or other deposits are applied first to enhance corrosion resistance. The main ingredient in all hexavalent chromium plating solutions is chromium trioxide (CrO3). Hexavalent chromium has been linked to cancer in humans following prolonged inhalation, and is toxic to aquatic life at relatively low concentrations. CHROMIUM

18. The Effluent Guidelines and Standards for Metal Finishing (40 CFR Part 433) are applicable to wastewater generated by any of these operations: Electroplating Electroless Plating Anodizing Coating Chemical Etching and Milling Printed Circuit Board Manufacturing. Discharges from 40 additional processes, including: painting, cleaning, polishing, shearing, hot dip coating, solvent degreasing etc. WASTEWATER GUIDELINES

19. Chemicals to be monitored include: Cadmium Chromium Copper Silver Zinc Cyanide Total Toxic Organics (TTOs) Oil and Grease TSS pH WASTEWATER GUIDELINES

20. Physical processes such as abrasive blasting, grinding, buffing, and polishing do not contribute as much to hazardous waste generation as chemical and electrochemical processes. The most common hazardous waste sources are rinse water effluent and spent process baths. These systems in turn generate solid and liquid wastes that are regulated under the provisions of RCRA. WASTE HANDLING

21. The air emissions from many metal finishing processes must be controlled using scrubbing or filtering equipment. These can generate further wastes that must also be treated, disposed, or recycled. Some of the processing solutions used in metal finishing have a finite life, especially conversion coating solutions, acid dips, cleaners and electroless plating baths. AIR EMISSIONS

22. Organic solvents, known as Volatile Organic Compounds (VOCs) are used in coatings such as paint, strippers/cleaners, etc. In the presence of sunlight, VOCs react in a complex reaction that produces ozone. Ozone is the major ingredient in photochemical smog. By reducing the amount of VOC in coatings, in combination with other efforts to reduce VOC emissions, you can help reduce ozone. Most air districts restrict the amount of VOC emissions allowed. VOLATILE ORGANIC COMPOUNDS (VOCs)

23. Coatings consist of solids (resin, pigments, extenders, additives) and solvents. Solvents lower the viscosity (reduce or thin), and act as the carrier for the solids. Solvents also are used to dissolve the solid resin. Solvents evaporate from the coating before, during and after application. Solvents include VOCs, water, and exempt solvents. VOC content means pounds of VOCs per gallon of coating (lb/gal) or grams of VOCs per liter of coating (G/L), minus water and exempt solvents (exempt solvents do not contain volatile organic compounds). VOC CONTENT

24. The VOC concentration does not change if you increase the volume of mixed paint used, however, the VOC concentration does increase when adding VOC solvents such as thinners or reducers. Manufacturers are currently being required by federal regulations to formulate paint to certain VOC specifications, that when used, according to the manufacturer’s recommendations, will meet VOC content limits. The VOC content is generally stated on the label or on the manufacturer’s paint specification sheet. VOC CONTENT

25. Information is from a Material Safety Data Sheet for this coating: If the coating weighs 10.4 pounds/gallon, and it contains the following VOCs: Xylene 2% x 10.4 lb/gal = .21 lb/gal Toulene 2% x 10.4 lb/gal = .21 lb/gal MEK 6% x 10.4 lb/gal = .63 lb/gal Mixed Aliphatics 10% x 10.4 lb/gal = 1.04 lb/gal TOTAL 20% x 10.4 lb/gal = 2.09 lb/gal 2.09 lb/gal x 119.8 (g/L) (gal/lb) = 250 grams/Liter CALCULATING VOC CONTENT

26. Water Borne - Water is the major solvent and includes water reducible and emulsions. These coatings usually include VOCs as co-solvents. UV Curable Coating - Liquid resin and pigment which uses UV light to cure the coating. High Solids - Coatings that contain greater than normal resin and pigment (70 - 80% by volume). Powder - Dry finely ground coating which is usually sprayed dry on an electrically charged surface and is later heated to its melting point so that the powder can flow together (3% VOCs by volume). TYPES OF COATINGS

27. Exempt Solvent based - Coatings that contain exempt solvents, primarily 1,1,1 TCA. These coatings usually include VOC as stabilizers and co-solvents. Electrodeposition - Dip coating process where water borne coatings are electrically "plated-out". Autodeposition - Dipcoat plating process without electrical charge. Catalyzed Coatings - Two or three component coatings which are mixed together prior to application. TYPES OF COATINGS

28. A photochemcially reactive is any solvent with an aggregate of more than 20% of its total volume composed of chemical compounds classified below: A combination of hydrocarbons, alcohols, aldehydes, esters, ethers, or ketones having an olefinic or cycle- olefinic type of unsaturation: 5%. b. A combination of aromatic compounds with eight or more carbon atoms to the molecule except ethylbenzene: 8%. c. A combination of ethylbenzene, ketones having branched hydrocarbon structures, trichloroethylene or toluene: 20%. PHOTOCHEMICALLY REACTIVE

29. Coatings and agents containing high VOC concentrations can be applied using the following high transfer efficiency methods: High-Volume, Low-Pressure coating system Electrostatic application Flow coat application Dip coat application Brush coat application Pre-packaged aerosol can application Roll coat application TRANSFER METHODS

30. Spray booth filters prevent paint overspray from traveling up the exhaust vent. Filters help increase the life span of the exhaust fans, reduce fire hazard, and provide protection from the deposition of paint particles outside the building. It is important to maintain your booth to ensure that your operation does not cause a public nuisance and violate air regulations. Paint overspray can travel through ineffective filters and damage the finish of automobiles and structures near your operation. Always make sure that the filters are installed properly and cover all openings. Remember that the filter media you use must be designed for your type of spray operations. SPRAY BOOTH FILTERS

31. A pressure drop gauge may be used to determine the pressure drop across the spray booth filters. As the filter pores become clogged, the pressure drop increases. Filters should be replaced according to manufacturer’s recommendations. Check your pressure gauge frequently for accuracy. SPRAY BOOTH FILTER PRESSURE

32. Waterwash booths should provide a continuous sheet of water down the face of the rear booth panel. The water sheeting collects the overspray from the painting operation and the particulates can be skimmed from the surface of the water for disposal. If the booth does not provide a continuous sheet of water, i.e. if dry spots appear, the water spray lines should be checked for clogged openings. Remove the booth from service and repair the water lines immediately. Never discharge your wastewater to the ground or storm drain system. KEEP YOUR CURTAIN WET

33. Transfer efficiency is the percentage of paint solids deposited on the surface of your product. The cost savings in paint consumption when using high transfer efficiency guns is significant. If you achieve 30% transfer efficiency, then 30% of the paint solids sprayed have adhered to the product, and 70% of the paint solids are on your floor, booth walls, and exhaust filters. You can get more paint to stay on the product if you use application methods with transfer efficiencies in excess of 65%, and you buy less paint. TRANSFER EFFICIENCY

34. High transfer efficiency saves paint and decreases emissions, thus lowering your costs. High transfer efficiency decreases your booth filter purchases, decreases your booth cleaning expenses, and may decrease your waste disposal costs. Train your painters to maximize their efficiency. Consider racking parts to make overspray land on a part. Make sure automatic spray lines spray the parts and not empty hooks. Spray corners of parts first so overspray hits uncoated areas of the part. WASTING PAINT

35. Use properly designed equipment Eliminate cross drafts Reduce air pressure in gun Allow dipped parts to drain Only spray the part For electrostatic painting - turn on power to electrostatic - keep a good clean ground - hook up the grounding strap OPERATING EQUIPMENT PROPERLY

36. Tightly seal all containers of coatings and solvents. Cans and drums should be equipped with tight fitting lids and should remain closed between uses to prevent evaporation. Large drums should have screw caps to cover the bung holes and should be opened only to empty or fill the drum. Use a pump or funnel when filling and make sure to close the drum completely when you are finished. Use new funnels that screw into the bung of drums and have a lid that clamps down on top of the funnel for a tight seal. STORING

37. Preparing a surface may entail using a solvent degreaser. Alternatives to solvent degreasing include using abrasives, water with surfactants, exempt solvents, alkaline washes, or acid etches. Switching from solvent cleaners to other surface preparation methods can save money and reduce disposal costs. SURFACE PREPARATION

38. Mixing Directions Coating manufacturers will supply you with instructions when the coating contains more than one component. Often the coatings must be mixed with a thinner and a catalyst. Always mix according to the instructions. FOLLOW MIXING DIRECTIONS

39. VOCs from your facility can be reduced significantly by cleaning your spray guns and other equipment properly. Never clean your lines by spraying solvents into the air or into the filters. Always direct the clean-up solvents, using minimal pressure, into containers to prevent evaporation. Remove atomization tips, soak and/or use a brush to clean the tip, then flush solvent through the gun (without the tip) into a container which is immediately sealed. Soak spray guns in closed containers and avoid the use of VOCs for clean-up whenever possible. CLEANING UP

40. Keep detailed records of the coatings applied at your facility. Monthly logs should detail the products purchased, including the name and number of the product, and the amount of product purchased, with the appropriate unit indicated (i.e., gallon, quart, pint). Remember that inspectors look for accurate records. One proven method of record keeping involves the use of ‘job tickets’ and a summary log. Many facilities instruct the operator to record coating information for each job on a production ticket at the booth. The job tickets are then summarized nightly by the supervisor. LOGS

41. Non-Cyanide Copper Plating Non-cyanide copper plating is an electrolytic process similar to its cyanide-based counterpart. Operating costs for the bath itself are higher for the non-cyanide process than the cyanide process. Non-cyanide copper plating benefits: Greatly reduces safety risks to workers. Greatly reduces the costs and complexity of treating spent plating solutions. Smaller risk to hydrogen cyanide exposure. Plating solution does not have to be treated for carbonates. APPLICATION TECHNOLOGY

42. Zinc-Alloy Electroplating Both zinc and zinc-alloy electroplating processes are very common and have a long history in the electroplating industry. Recently these processes have been considered as possible replacements for cadmium coatings. Benefits of zinc and zinc-alloy Eliminates workplace exposure to cadmium and cyanide. Corrosion resistance as good as cadmium. Better wear resistance than cadmium. Zinc-cobalt deposits show good resistance to atmospheres containing SO2. APPLICATION TECHNOLOGY

43. The Blackhole Technology Uses an aqueous carbon black dispersion at room temperature for preparing through-holes in printed wire boards for subsequent copper in the through-holes. Benefits of Blackhole Technology Process Simplification - requires fewer process steps as well as associated chemicals and rinses. Contamination Reduction - does not use formaldehyde. Ease of Implementation - uses existing equipment in an electroless copper process line. Acceptable Product Quality - accepted under MIL-P-5511OD. Lower Operating Costs APPLICATION TECHNOLOGY

44. Ion Vapor Deposition of Aluminum (IVD) In IVD, the coating metal is evaporated and partially ionized before being deposited on the substrate. A typical IVD system consists of a steel vacuum chamber, a pumping system, a parts holder, an evaporation source, and a high-voltage power supply. Benefits of this technology Health and safety risks can be greatly reduced when IVD is used in place of cadmium electroplating. The greatest advantage of aluminum IVD is that the process significantly reduces the generation of hazardous wastes, and potentially eliminates the need for special pollution control systems. APPLICATION TECHNOLOGY

45. Physical Vapor Deposition (PVD) A thoroughly cleaned workpiece is placed in a vacuum chamber, and a very high vacuum is drawn. The chamber is heated to between 400o and 900o F. A plasma is created from an inert gas such as argon. The workpiece is first plasma-etched to further clean the surface. The coating metal is then forced into the gas phase by either evaporation, sputtering or ion plating. Benefits of PVD PVD results in a thin, uniform coating that is much less likely to require machining after application. PVD titanium nitride coatings have already gained wide acceptance in the cutting tool industry. APPLICATION TECHNOLOGY

46. Chromium-free Surface Treatments for Aluminum and Zinc   Chromium-free surface treatments for aluminum and zinc are relatively new. One of the few commercially proven, non-chromate surface treatments for aluminum is an inorganic conversion coating based on zirconium oxide. A recent chrome-free post-rinse process has been developed for use on phosphated steel, zinc, and aluminum surfaces prior to painting. The new rinse, known as Gardolene VP 4683, contains neither hexavalent or trivalent chrome. It contains only inorganic metallic compounds as the active ingredient. APPLICATION TECHNOLOGY

47. Metal Spray Coating   Molten Metal -The metal is heated by some suitable means (either resistance heating or a burner) and then supplied to the atomizing source in molten form. Fuel/Oxidant - Oxygen/acetylene flames are typically used. The metal melts as it is continuously fed to the flame in the form of a wire or powder. Electric arc - In this method an electric arc is maintained between two wires that are continuously fed as they melt at the arc. These technologies for thermal spraying of metals are well developed, but they tend to have their own market niche and are not typically thought of as a replacement for electroplating. APPLICATION TECHNOLOGY

48. Non-Cyanide Metal Stripping Many non-cyanide stripping solutions are typically proprietary formulations, the detailed chemistry of coating removal is not known for most solutions. Non-cyanide metal strippers have the following benefits: Significant potential for reducing waste treatment costs. Often easier to recover metals from spent solutions. Bath life is longer because higher metal concentrations can be tolerated. COATING REMOVAL TECHNOLOGY

49. Plastic Media Blasting (PMB) PMB uses low-pressure air or centrifugal wheels to project plastic media at a surface. The blast particles have sufficient impact energy, coupled with hardness and geometry to chip away or erode the coating. Some of the major beneficial aspects of PMB include: High stripping rate Eliminates water use Can selectively remove individual coating layers Often done with recyclable thermoplastic media Fully automated robotic systems available Fully developed systems available No size limitations on parts to be stripped. COATING REMOVAL TECHNOLOGY

50. Wheat Starch Blasting Wheat starch blasting uses low-pressure air to propel particles at the painted surface. The coating is stripped away by a combination of impact and abrasion. Similar equipment and techniques to PMB. Some of the major benefits include: Moderate stripping rates can be achieved while maintaining a gentle stripping action. Safe on soft clad aluminum and composites Eliminates water use Can selectively remove individual coating layers Uses inexpensive stripping media Media are nontoxic and biodegradable COATING REMOVAL TECHNOLOGY