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Why and how to use a custom coater for electrocoating
Why and How to Use a &t&m Electrocoating
Coater for
by Ron Jacob Finishing
Heir, LLC. Neshkoro,
Wis.
0th OEMs and other custom manufacturing operations can use a custom coater in several ways. Since they specialize in electrocoating (E-coat) (sometimes along with plating, powder coating, or liquid painting), they have solved many of the finishing problems that a manufacturer or end-user may not have even considered. They typically are accustomed to short lead times and excellent customer service. Tooling, quality (including rework), and packaging are daily considerations that custom coaters deal with and are sources for cost reduction with on-going customers.
B
WHAT A CUSTOM
COATER OFFERS
E-coating is a finishing system that usually produces a significant square footage of metal parts in one color in a very efficient manner. Most systems can coat thousands (up to one million or more) square feet of surface area in one day with zero application labor cost. While multicolor systems are available, most custom coaters only offer one or two colors with limited resin systems. Other efficiency factors to consider are that virtually 100% of the part is coated with a very uniform film thickness at 95+ % transfer efficiency. E-coat systems are one of the most expensive equipment investments for finishing and include pretreatment (with quality water), E-coating, adequate curing, and waste treatment. The custom coater has already made the investment and is used to dealing with environmental concerns (including VOC reporting and dealing with wastewater). They also have tooling (hooks, hangers, racks, etc.) for a wide variety of part sizes and configuration. Probably their greatest assets are customer service and efficiency (pieces per hour) with available manpower. Since coating is their only job, they must do it well and at a competitive price. Quality and packaging options are two other features that custom coaters regularly deal with. They are familiar with IS0 and QS quality systems and have the testing equipment to monitor all aspects of coating from film thickness to corrosion resistance. Since coating quality starts with a clean part, custom coaters must having a cleaning system that can December 2001
handle any incoming soil condition. Packaging options can significantly effect the part cost and custom coaters again have seen methods from returnable to bulk packaging. They can help design various packaging that is efficient for the fabricator, themselves, and the end-user. COATINGS
AVAILABLE
Since the equipment cost is so significant and throughput is so great for an E-coat system, most systems are limited to a couple of resin systems and limited colors. This is especially true of custom coaters as they usually have a set of major customers based on a color and resin system such as automotive primer or agricultural/lawn and garden topcoat. The E-coat manufacturers have a wide variety of colors, glosses, and resin systems including “wet look” and two-coat (primer and topcoat). Almost all E-coats are free of heavy metal, yet provide excellent corrosion resistance. They all have zero-to-low VOC content and extremely high transfer efficiency; however, due to the large throughput of an E-coat system, custom coaters seldom install multiple colors or more than one resin system, unless they have a guaranteed long-term commitment from a customer or end user. While end users may specify a liquid or powder coating, E-Coat can provide equal or better quality but may require some negotiating on film thickness, orange peel, or other specified items. For instance, parts that are specified to be powder coated semigloss black and are not exposed to direct sunlight can be E-coated. A cathodic epoxy coating with lower average dry film thickness but 100% coverage (without the Faraday cage problems of powder) will provide better corrosion protection. WHAT INFORMATION NEED?
DOES THE CUSTOM
COATER
Part substrate, size, quantity, and quality requirements (including packaging) are needed for a custom coater to adequately quote a coating price. Virtually all metal parts can be E-coated. Special considerations may be needed for castings, powder metal, and aluminum parts with high aesthetic requirements. A mixture of substrates can usually be han31
dled by the proper chemical pretreatment and should be discussed between the custom coater and their chemical and coating suppliers. Substrates should not have any type of sealer or chemical conversion as these coatings will interfere with the pretreatment system. Castings and powder metal parts need special consideration to deal with the porosity of the part. Part size is not as important as configuration since “air pockets” and “puddles” can be more of a challenge for E-coat since it is an immersion process. Air pockets cause bare (or thinly coated) areas on the part if air gets trapped as the part is immersed in the coating. Some E-coaters have developed special tooling to “burp” the part, but this can be costly and should be handled with part design or the addition or relocation of holes to allow the air to escape. A similar problem exists if the part design traps coating during the immersion (a “puddle”) and drags coating out into the postrinse system. Again, tooling can help this situation but holes can also help. Quantity requirements are important to a custom coater from a scheduling standpoint. Very small or very large quantities do not effect them as much as drastic changes in the schedule with little warning. They can even maintain some raw or finished goods inventory, if they are given the flexibility of a longterm view of requirements. Since they are accustomed to running multiple customers with the same coating, small quantities do not effect an E-coat custom coater like other coatings. Packaging can also effect quantity runs. Packaging probably has more effect on the cost of a part than any other factor and is, therefore, critical at the time of quoting. Incoming packaging can effect labor in storing and handling the part, and the
outgoing packaging effects the labor and material cost. Packaging can also be critical to the quality of the part as it is shipped and received at the enduser. While packaging cost is important, quality problems caused by inadequate packaging can be long-term. A joint understanding (or meeting) with the fabricator, coater, and end-user can usually help explain quality levels and packaging needs. With their experience, a custom coater can quite often help with packaging design. HOW DO YOU FIND A OUALIFIED E-COAT YOUR PARTS?
CUSTOM
COATER TO
The Electrocoat Association (www.electrocoat.org) is an excellent source of custom coaters and E-Coat and equipment suppliers. Local or state trade associations, such as Chemical Coaters International and the Internet, are also good sources. Even if you plan to install an E-Coat system of your own, the use of a custom coater as a starting point can be beneficial as long as the custom coater knows your longterm plans. You may find that they are your longterm solution without needing to make the capital investment for equipment or environmental considerations. If you think you have a unique application or are trying to make an in-houseloutsource decision, a consultant can quite often help review the options. If you are in a location with several custom coaters, getting opinions from other fabricators, a purchasing agents association, or paint and chemical suppliers can help select the best source. Since transportation will also effect part cost, if a custom coater provides pickup and delivery service, that can reduce cost. Custom coaters are always dealing with transportation situations and may be able to help find economical sources. MF
RELIABLE pH/ORPCONTROL * modular pH or ORP design 0 2 -0~ 4 point controller available 0 indicator can be upgraded to a recorder 0 panel or NEMA mount
* supplied with controller, indicator, pump,
.
& . ..probes.
repairs and more! -
I-
probe and bulfen + unidirectional proportional control * adjustablebellows pump for acid/alkaliservice
www.analyticalmeasurements.com 621 Ramsev AL
Circle 006 on reader card or go to www.thru.to/webconnect December
2001
33
Coater for
by Ron Jacob Finishing
Heir, LLC. Neshkoro,
Wis.
0th OEMs and other custom manufacturing operations can use a custom coater in several ways. Since they specialize in electrocoating (E-coat) (sometimes along with plating, powder coating, or liquid painting), they have solved many of the finishing problems that a manufacturer or end-user may not have even considered. They typically are accustomed to short lead times and excellent customer service. Tooling, quality (including rework), and packaging are daily considerations that custom coaters deal with and are sources for cost reduction with on-going customers.
B
WHAT A CUSTOM
COATER OFFERS
E-coating is a finishing system that usually produces a significant square footage of metal parts in one color in a very efficient manner. Most systems can coat thousands (up to one million or more) square feet of surface area in one day with zero application labor cost. While multicolor systems are available, most custom coaters only offer one or two colors with limited resin systems. Other efficiency factors to consider are that virtually 100% of the part is coated with a very uniform film thickness at 95+ % transfer efficiency. E-coat systems are one of the most expensive equipment investments for finishing and include pretreatment (with quality water), E-coating, adequate curing, and waste treatment. The custom coater has already made the investment and is used to dealing with environmental concerns (including VOC reporting and dealing with wastewater). They also have tooling (hooks, hangers, racks, etc.) for a wide variety of part sizes and configuration. Probably their greatest assets are customer service and efficiency (pieces per hour) with available manpower. Since coating is their only job, they must do it well and at a competitive price. Quality and packaging options are two other features that custom coaters regularly deal with. They are familiar with IS0 and QS quality systems and have the testing equipment to monitor all aspects of coating from film thickness to corrosion resistance. Since coating quality starts with a clean part, custom coaters must having a cleaning system that can December 2001
handle any incoming soil condition. Packaging options can significantly effect the part cost and custom coaters again have seen methods from returnable to bulk packaging. They can help design various packaging that is efficient for the fabricator, themselves, and the end-user. COATINGS
AVAILABLE
Since the equipment cost is so significant and throughput is so great for an E-coat system, most systems are limited to a couple of resin systems and limited colors. This is especially true of custom coaters as they usually have a set of major customers based on a color and resin system such as automotive primer or agricultural/lawn and garden topcoat. The E-coat manufacturers have a wide variety of colors, glosses, and resin systems including “wet look” and two-coat (primer and topcoat). Almost all E-coats are free of heavy metal, yet provide excellent corrosion resistance. They all have zero-to-low VOC content and extremely high transfer efficiency; however, due to the large throughput of an E-coat system, custom coaters seldom install multiple colors or more than one resin system, unless they have a guaranteed long-term commitment from a customer or end user. While end users may specify a liquid or powder coating, E-Coat can provide equal or better quality but may require some negotiating on film thickness, orange peel, or other specified items. For instance, parts that are specified to be powder coated semigloss black and are not exposed to direct sunlight can be E-coated. A cathodic epoxy coating with lower average dry film thickness but 100% coverage (without the Faraday cage problems of powder) will provide better corrosion protection. WHAT INFORMATION NEED?
DOES THE CUSTOM
COATER
Part substrate, size, quantity, and quality requirements (including packaging) are needed for a custom coater to adequately quote a coating price. Virtually all metal parts can be E-coated. Special considerations may be needed for castings, powder metal, and aluminum parts with high aesthetic requirements. A mixture of substrates can usually be han31
dled by the proper chemical pretreatment and should be discussed between the custom coater and their chemical and coating suppliers. Substrates should not have any type of sealer or chemical conversion as these coatings will interfere with the pretreatment system. Castings and powder metal parts need special consideration to deal with the porosity of the part. Part size is not as important as configuration since “air pockets” and “puddles” can be more of a challenge for E-coat since it is an immersion process. Air pockets cause bare (or thinly coated) areas on the part if air gets trapped as the part is immersed in the coating. Some E-coaters have developed special tooling to “burp” the part, but this can be costly and should be handled with part design or the addition or relocation of holes to allow the air to escape. A similar problem exists if the part design traps coating during the immersion (a “puddle”) and drags coating out into the postrinse system. Again, tooling can help this situation but holes can also help. Quantity requirements are important to a custom coater from a scheduling standpoint. Very small or very large quantities do not effect them as much as drastic changes in the schedule with little warning. They can even maintain some raw or finished goods inventory, if they are given the flexibility of a longterm view of requirements. Since they are accustomed to running multiple customers with the same coating, small quantities do not effect an E-coat custom coater like other coatings. Packaging can also effect quantity runs. Packaging probably has more effect on the cost of a part than any other factor and is, therefore, critical at the time of quoting. Incoming packaging can effect labor in storing and handling the part, and the
outgoing packaging effects the labor and material cost. Packaging can also be critical to the quality of the part as it is shipped and received at the enduser. While packaging cost is important, quality problems caused by inadequate packaging can be long-term. A joint understanding (or meeting) with the fabricator, coater, and end-user can usually help explain quality levels and packaging needs. With their experience, a custom coater can quite often help with packaging design. HOW DO YOU FIND A OUALIFIED E-COAT YOUR PARTS?
CUSTOM
COATER TO
The Electrocoat Association (www.electrocoat.org) is an excellent source of custom coaters and E-Coat and equipment suppliers. Local or state trade associations, such as Chemical Coaters International and the Internet, are also good sources. Even if you plan to install an E-Coat system of your own, the use of a custom coater as a starting point can be beneficial as long as the custom coater knows your longterm plans. You may find that they are your longterm solution without needing to make the capital investment for equipment or environmental considerations. If you think you have a unique application or are trying to make an in-houseloutsource decision, a consultant can quite often help review the options. If you are in a location with several custom coaters, getting opinions from other fabricators, a purchasing agents association, or paint and chemical suppliers can help select the best source. Since transportation will also effect part cost, if a custom coater provides pickup and delivery service, that can reduce cost. Custom coaters are always dealing with transportation situations and may be able to help find economical sources. MF
RELIABLE pH/ORPCONTROL * modular pH or ORP design 0 2 -0~ 4 point controller available 0 indicator can be upgraded to a recorder 0 panel or NEMA mount
* supplied with controller, indicator, pump,
.
& . ..probes.
repairs and more! -
I-
probe and bulfen + unidirectional proportional control * adjustablebellows pump for acid/alkaliservice
www.analyticalmeasurements.com 621 Ramsev AL
Circle 006 on reader card or go to www.thru.to/webconnect December
2001
33