Choosing the Right Vacuum Impregnation Program

In-sourcing vacuum impregnation is a choice that many OEMs consider, to reduce manufacturing costs for critical components. A North American motorcycle manufacturer made that choice more than a decade ago, considering multiple sealant formulae and different equipment and technologies.

The OEM was sold on equipment that claimed to eliminate wastewater discharge, seal castings at a better rate, and would require minimal adjustments, maintenance, and repair. The equipment they selected used a recycling sealant.

A new challenge. Over time, the motorcycle manufacturer discovered that what it had been sold was different from the reality of what it had acquired. It found that the recyclable sealant’s chemistry changed over time, and so did the recovery results. The nature of recyclable sealant required it to be mixed with water in the impregnation process. While the sealant was pure at first, it lost its properties once in contact with water, and never returned to its original formulation.

Also, a wash-water conditioner was needed to maintain the sealant effectiveness. But, for the sealant to work effectively this conditioner had to be added daily, and at an exact ratio. If the ratio was not correct, then the sealant became unstable. The OEM found that excess chemicals carried into the wash and cure modules increased part contamination and damaged the system.

The system proved to be remarkably expensive, too. The manufacturer booked costs totaling more than $1 million due to scrap parts, repairs, maintenance, labor, sealant consumables, and sealant support chemistry. The cost of managing the system exceeded the cost to outsource the impregnation process.

The realization set in that its vacuum impregnation strategy needed to change, and the manufacturer had an opportunity to make that change at the start of a new crankcase program. It designed a new, lighter crankcase that required 100% of the parts to be sealed. Based on prior experience and data, the manufacturer determined it had to overcome three main challenges when selecting a new impregnation system.

Maintenance cost. The initial impregnation system had a remarkable rate for component replacement. The manufacturer needed its new system to be easier system to operate with less maintenance.

Sealant management. The recyclable sealant required excessive testing and maintenance. The manufacturer needed a sealant that maintained its original formulation, and that does not require daily maintenance by multiple departments.

Poor recovery.  The system had a fall-out rate of approximately 14% of the castings. Any parts that were not recovered were scrapped, and the cost of the scrapped castings totaled approximately $967,000. The manufacturer needed to recover more castings.

The right solution. Godfrey & Wing recommended its Continuous Flow Impregnation (CFi) system Dry Vacuum & Pressure (DVP) process and 95-1000AA recoverable sealant. The CFi uses Godfrey & Wing’s Dry Vacuum and Pressure (DVP) impregnation process, which incorporates a fast, deep vacuum to evacuate the air from the porosity. After moving sealant into the chamber, high-pressure forces the sealant deep into the casting. 

The 95-1000AA recoverable sealant remains pure throughout the entire process. The CFI’s impregnation module is designed to recover the sealant in its original formulation. Once the part is impregnated, the part moves to a centrifuge to recover any unused sealant. The unused sealant is returned to the sealant reservoir for future cycles. By retaining the pure sealant, the customer can maximize recovery with no additives, or excessive maintenance.

After impregnation, the part moves to the CFi’s wash and cure stations. Because there is no excess sealant, the wash-water remains clean. This makes it possible for the part to be properly washed and part contamination is eliminated.

The CFi was designed with maintenance and service at top-of-mind. The internal components are positioned to enable ease of maintenance without interrupting production. The maintenance team can service principal components through the rear access panels. Quick disconnect fittings are used so that they can be maintained by hand without the need for specialty tools. Each module has a line-rated disconnect so that maintenance does not need to power down the entire system for service.

While the system and sealant seemed to be the right solution, the manufacturer wanted to learn more about the technology and sealant more directly – in real time. Godfrey & Wing linked the manufacturer in contact with a service center that operates a CFi and uses a recoverable sealant.

The manufacturers’ technicians toured the service center to learn about the technology, which proved that the process and recoverable sealant remain reliable and do not require constant maintenance or user intervention. They were impressed with the CFi’s throughput, efficiency, and simplicity, and based on this experience, and data presented, the manufacturer purchased a CFi.

Better results. The CFi was installed, operators and maintenance teams were trained, and the system processed parts immediately. Since then, the CFI has been addressing the manufacturer’s three challenges:

Reduced maintenance cost. The plant is expected to save approximately $35,000 in maintenance and spare parts annually.

Efficient, easy sealant management. The motorcycle manufacturer no longer needs to purchase wash-water conditioner, and sealant maintenance and oversight is significantly reduced. The manufacturer will save approximately $20,000 per year in sealant costs.

Improved casting recovery. The CFi’s First Time Through (FTT) rate is 99% – a 14-point increase over the previous recovery rate that will save approximately $630,000 per year in recovered castings.

In total, the cost savings and improved recovery is expected to save the manufacturer approximately $685,000 per year, enabling the capital expense recovery to be less than 24 months. The CFi’s productivity and ease of maintenance has changed the motorcycle manufacturer’s impression of vacuum impregnation.

Choosing the right impregnation process and sealant is a critical aspect of purchasing in-house vacuum impregnation equipment. Once the decision is made, it cannot be reversed.

By analyzing system data through due diligence, this manufacturer selected the right equipment and the sealant that suits its needs. The CFi with recoverable sealant transformed the manufacturer’s impregnation process by reducing costs, increasing quality and improving efficiency.

Andy Marin is the marketing coordinator for Godfrey & Wing, a developer of vacuum impregnation technology. Contact him at [email protected]