MetalCraft Marine of Kingston, Ontario manufactures high-speed aluminum boats that are used by fire crews, rescue patrols, and military personnel. The diesel engines that power these watercraft support top speeds but can be loud. To reduce noise from the engine bay, the boat builder installs custom-fabricated acoustic insulation that’s made of different rubber materials.

Compared to fabricated metal, industrial rubber products like this may seem inconsequential in terms of cost. Plus, some manufacturers and machine shops just assume they can fabricate rubber for less than they can buy finished gaskets. Yet companies like this aren’t accounting for shop waste. They’re not just ignoring scrap. They’re adding unnecessary labor costs and wasting the time and talents of workers.

MetalCraft Marine provides a counterpoint to incorrect assumptions about costs and waste. The Kingston, Ontario company is expert at fitting and welding, but understands that the in-house fabrication of rubber products is time-consuming and can be inefficient. By learning from this boat builder’s example, metal fabricators and manufacturers alike can save time and money.    

Before MetalCraft Marine began buying outsourced acoustic insulation, the Kingston company asked its fitters to fabricate and install these industrial rubber products. The results could be inconsistent. “Some fitters were better at it than others,” says Project Manager Chris Toller. Welders also had to work with the fitters and show them where to add tabs. “There were a lot of little pieces to weld in place,” he says.   

Welders weren’t the only higher-paid employees worrying about rubber insulation instead of metal parts. Project managers also needed to ensure that acoustic insulation was cut cleanly and installed easily. At a a busy company, there’s an opportunity cost whenever employees can’t perform the tasks for which they’ve been trained. That’s especially true with welders, who are in high demand in today’s job market.     

Fitters are also a source of talent – and are good at solving problems. At MetalCraft Marine, they used a cardboard template to measure and trace the acoustic insulation. “They had to be very creative,” Toller says. With repeated use, however, the edges of a cardboard template become jagged. If the resulting cuts share these inconsistent contours, insulation may not mate cleanly with other parts such as panels.

Of course, employees can also use jigs and fixtures with band saws and jig saws instead. Yet a simple mis-cut can result in the waste of an entire rubber sheet. Insulation can be nested during cutting to maximize material yield, but not every machine shop or manufacturer has the right equipment. MetalCraft Marine outsourced some cutting, but parts made of softer materials would arrive with scratches.

How to Reduce Shop Waste

To reduce shop waste, increase operational efficiency, and secure defect-free rubber parts, MetalCraft Marine chose a complete solution. The boat builder asked Elasto Proxy, a rubber fabricator, to supply custom acoustic insulation. These rubber parts are cut with computer-controlled water jet equipment, packaged securely in carboard boxes, and arrive in kits that are ready-to-use.

Before MetalCraft Marine outsourced its rubber fabrication, “the hardest part was the removable panel with bolt holes,” Toller says. With Elasto Proxy’s water jet cutting, however, openings for fasteners and even chamfered cuts are readily achievable. This cutting technique also creates smooth lines for acoustic insulation that mates snugly with panels and is free from gaps that can admit unwanted engine sounds.

In addition to reducing shop waste, water jet cutting supports the use of multi-layer composites for acoustic insulation. In these sandwich-like structures, each rubber material provides particular properties. Machine shops and manufacturers who aren’t familiar with rubber’s sound dampening, blocking, or absorbing qualities can choose an off-the-shelf material instead, but it won’t optimize noise control.

To avoid material waste that’s caused by excessive ordering, MetalCraft Marine receives custom-packaged kits that contain all of the insulation that’s needed for a boat build. “When we order a kit from Elasto Proxy, it contains every part that we need – nothing more,” says Toller. The quoted time is three weeks, but some shipments arrive in two. “We’ve even gotten some rush orders,” Toller adds.

MetalCraft Marine also reduces waste by using insulation that attaches with an adhesive. “When the kit from Elasto Proxy arrives, we can complete our installation in a few hours instead of a couple of days,” Toller says. The labor savings is significant, but the Project Manager also likes kitting’s repeatability and dependability. “We can repeat the kit over and again with a really nice design,” he explains.

By choosing outsourced insulation instead of in-house fabrication, MetalCraft Marine is reducing shop waste while realizing other important business benefits. Welders can weld, fitters can fit, and the custom acoustic insulation the boat builder installs underscores the quality of its products. “We looked for a solution for a long time,” Toller says. They finally found one.

To learn how you can reduce shop waste, contact Elasto Proxy.

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