Smaller sealer dispensing tank cuts waste, improves controls

Features - Sealing

Graco’s 55 gallon tank replaces a 300 gallon system for an American automotive manufacturer.


When a major American automotive manufacturer faced changing production demands, excessive waste, and difficult controls in their paint shop sealant dispense system, they looked to supply systems from Graco Inc. for a solution. Consulting with the manufacturer’s engineering team, Graco replaced another manufacturer’s 300 gal dispense system with a 55 gal tandem system that reduces material waste and improves ease of use for the customer.

The sealer deck supply system plays a critical role in automotive paint shop operations – covering body seams formed when pieces of metal are spot welded together in the body-in-white process – sealing the body from water on the road. Therefore, this process can have significant impact on production efficiency and cost. When a sealant dispense system in one major American automotive manufacturing facility’s sealer deck was out of date and poorly matched to its current production demands, it caused a great deal of unnecessary material and time waste.

The system in place was a 300 gal, single drum assembly installed 30 years ago when the facility was manufacturing large van bodies. A change to manufacturing smaller-bodied vehicles required significantly less sealant, with material usage decreasing 30%. Additionally, the existing system had a complex control panel that led to a large number of mistakes, particularly in material release and pump purging. Training and maintenance on this system were inadequate, and the system’s depressurization procedure was complex. Finally, without an option for depressurizing the pumps before performing material purges, as much as 10 gal of material was wasted during each purge, occurring as frequently as 3x per week.

Upon the recommendation of a vendor, the manufacturer reached out to Graco for a sealer deck pump solution that could meet production demands; reduce waste; improve ease of use; and deliver adequate power, system pressure, and flow rate.

System transition

Graco collaborated with the manufacturer, material supplier, and American Industrial, Graco’s distributor, to size a new pumping system to replace the current 300 gal system. The new system has tandem 55 gal drums and a Graco air motor, featuring intuitive controls.

“The controls for the previous system were complex – even though everything was labeled, it was difficult to recognize the functions of different controls, and that led to a lot of mistakes,” says Darin Bushong, Midwest account manager for Graco’s Advanced Fluid Dispense division who oversaw the project. “In the new Graco system, the controls are very simple. There are three gauges and a pneumatic tree with a three-way valve, making it easy for operators to understand the controls at first glance.”

He adds, “Changing from the 300 gal drum to the 55 gal drums also enabled us to place the controls at eye level, eliminating the risk and hassle of operators needing to adjust the controls and perform bleeding and purges from a stepladder.”

Additionally, the transition from a larger to a smaller system enabled the manufacturer to reduce waste.

“With the enormous drum on the prior system, material would sit in the drum for several weeks at a time and eventually become unusable,” Bushong says. “The new drums are changed more frequently, thereby ensuring that all of the material in them will be used before it must be discarded.”

Waste reduction

The supply system also cuts waste through a depressurization kit, which allows the manufacturer to depressurize the pumps and drive excess material back under the platen and recirculate it within the drum. Compared to the previous system, which required that the pump be purged from the filter, frequently wasting as much as 10 gal of sealant material per purge, the depressurization feature of the new system significantly cuts down on waste. The supply system’s design has also improved pressure and flow rate.

“You have to understand the number of drops that are in the system, the types of materials being used, and really do your due diligence in sizing the system before installation in order to ensure that the power, flow rate, and head pressure are adequate,” Bushong says. “Especially in automotive settings, our team’s experi- ence is invaluable to designing systems with superior performance.”

Special features

Graco engineers worked with counterparts at American Industrial to deliver a specialized feature requested by the customer. Given that the system was being downsized from a 300 gal drum to tandem 55 gal drums, drums would need to be changed approximately 3x more frequently. The manufacturer wanted to be sure that they would be able to remotely communicate with the system and receive alerts when drum changes are necessary. American Industrial and Graco Supply Systems teamed up to equip the new system with a programmable logic controller (PLC), allowing operators to communicate with the sealant dispense system from the control room.

“Making a change like this, from the large single drum system to the smaller tandem drum system, is rare, since it is difficult to assure adequate pressure and flow rates – other supply pumps companies simply don’t have the pump size and air motor power that we can deliver with our 55 gal drum system,” Bushong says. “Our expert team was not only able to make this system viable for the customer, we were able to do so while implementing simpler controls, drastically cutting material waste, and actually improving power, pressure, and flow rate.”

Graco Inc.