Evans Evco contracted with a metalizing company with the highest volume in the U.S., a firm that provides plasma spray services for refurbishing metal parts for commercial and governmental aerospace accounts. This metalizing company processes four primary turbine engine parts — compressor blades, fan blades, variable veins and inlet guide veins (IGVs).

The advantages of plasma spraying are numerous, with significant cost savings for aerospace applications. Applying a new metal surface eliminates labor-intensive re-working, while restoring worn areas, gaps and corrosion without sacrificing the safe function of the part. Plasma spraying results in a scrap rate of less than 1%, but in most cases, this company has the ability to restore all the parts in an order.

In an ideal application, a metal part would require a uniform coating of plasma spray. In reality, plasma spraying is needed only in targeted zones of the part. Because if other areas get hit by overspray, the added metal coating would alter the appearance, fit and function of the part. Even a small amount of unwanted coating can knock the tolerance out of range.

Common solutions to mask off or remove the overspray creates another set of headaches for the metalizing company.

• Manual removal with machining raises the risk of damage to the metal. Damaged areas can sometimes be reworked and re-coated, while adding time and expense to the project. When there’s extreme damage from manual removal, however, the part ends up being scrapped.
• Liquid masking is designed to stand up to the very high temperatures of plasma spray, effectively blocking critical areas from getting hit. The downside: Liquid masks require a lengthy curing time followed by the need for skilled labor to remove the used masking material, both of which elevate the costs of metaling services, while extending production time.

The metalizing company contracted with Evans Evco to manufacture a quicker, almost foolproof solution against overspray: high-temperature adhesive tape that’s cut in the exact configurations to protect specific areas from being hit.

The metalizing company provided CAD drawings along with a sample of the part that required reworking, so Evans Evco could design a tape solution, and create a metal die to the exact dimensions of the area that needed masking. They also provided Evans Evco their performance requirements of the masking material, so it would stand up to the extreme conditions, while being easy to remove.

The specialists at Evans Evco drew on their technical resources and expertise to identify the best thermal tape for masking against plasma spraying. Because of Evan Evco’s Preferred Converter Partnerships with top brands like 3M and Saint-Gobain, they had direct access to the up-to-date products and technical information direct from the manufacturer. These partnerships provide accurate information, great pricing and priority delivery, so the metalizing company knew they were getting a high-quality product.

They selected Saint-Gobain 2925-11R, Greenbelt 170- 10S, 3M 470L and 4712 for plasma spray masking because these had the conformability, heat resistance, clean removability and lower profiles due to less layering.

The custom-cut thermal tape selected and manufactured by Evans Evco helped the metalizing company meet their targets to make plasma spray operations more accurate and more efficient.