Industry Forum

About a year ago, our Product Design Engineering group came to me looking for a new marine paint coating that could be applied to a new outboard engine. For practical and budgetary purposes, a low-cost paint-application process was also needed.

This project quickly transitioned from prototype to preproduction status, and corporate was anxious for the visual “paint finish” presentation.

Our group needed to find coatings that would meet performance requirements and EPA regulations.

We investigated different paint coating systems and vendors, and decided on a paint system developed by Northern Coatings and Chemical Co. (Menominee, MI), which specializes in special-purpose coatings. Northern Coatings and Chemical Co. has previously supported our company’s special-coating needs with a great deal of success.

After testing and reviewing the performance of the product against freshwater marine specifications and making sure it met all of the environmental-related rules, we found that a dual system—primer and topcoat—would be the choice.

I would like to share the four-point procedure we used to achieve success in developing a new coating and application process.

1. We organized a team that included the manufacturing production operational manager, quality control manager, process engineer, cost analyst and finishing engineer. These individuals were chosen to expedite the decision-making and keep the project on schedule.

2. We reviewed all the paint application systems being used at B&S satellite plants to determine if any one of them would work for this product. Marine coatings were acquired from six of our suppliers. We applied them with the various coating systems to make observations and decisions on both equipment and coating material.

3. The B&S internal laboratory and an independent certified laboratory conducted performance evaluations.

4. The project was to be completed in five phases: paint 50 units with the new chosen application equipment and new paint; review of the equipment and paint performance by the finishing team; paint 300 units; review by finishing team and test market with a controlled release of all units; and perform a full day of paint production.

The primer is a high-solids, two-component epoxy primer. This is a flat, smooth finish with excellent electrostatic properties and over 500 hours corrosion resistance per ASTM B117.

The topcoat is a nonisocyanate, two-component high-performance acrylic. The topcoat is a low-gloss black or camouflage base color with a smooth finish. The camouflage base is capable of being coated with various camouflage patterns.

The application process combines automation and manual technology. The process is capable of being fully automated when undergoing full production levels. Electrostatic rotary atomizers (bells) provide the primary application. Areas that need additional reinforcement are coated with automatic or hand-held HVLP spray guns. These unique types of coatings spray out excellently with both types of spray equipment because the mixed paint product exhibits very moderate viscosity. This system yields about 75 to 80% paint efficiency on these types of parts. The unit is coated as one complete assembled part. The coatings are very operator-friendly, and cleanup of the equipment is as easy as any single-component coating, allowing for quick and smooth color change. The pot life of both primer and topcoat is between eight and 24 hours, depending on paint room environmental conditions.

Briggs & Stratton is producing a high-quality marine-engine package for freshwater performance. Now we have a five-hp, four-cycle, EPA/CARB-compliant OHV engine with an easy-to-start Magnetron Electronic Ignition with a very visually stimulating finish for the customer.

From a finishing engineer’s perspective, I realize demands were put on us that stretched the limits of coating technology. But the demands provided an opportunity for us to develop an innovative, high-tech, environmentally friendly special-purpose coating, and the challenge was stimulating.