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Old 12-16-2009
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There is a lot to this than you seem to have gleaned but to start from the beginning the most typical form of chrome electro- plating is triple plating which uses copper alloy as the base coat, a variety of alloys, but usually nickle based, for the second plated coat, and a finish plated coat of Chrome. It does not matter whether you are doing an engineered chrome finish (AKA Industrial or hard coat) or decorative on bronze, bare metal chrome plating needs to be a triple plated process in that chrome does not adhere well directly to the bronze or most other metals. Looking at the wear pattern on my Lewmars they were clearly triple plated originally.

The difference between engineered chrome plating and decorative chrome plating (besides minor differences in the alloys) is that engineered chrome plating is a much thicker coating layer than decorative (thousands of an inch vs millions of an inch and occasionally decorative plating only has a nickel base plate layer). The engineered chrome has enough thickness to stand up to pressure applied to its surface. Since nickel and copper are softer metals, the sheer thinness of the decorative coat makes it seem softer and to fail more easily. A carefully prepared and plated Industrial Chrome plating should last a decade or more in use on a winch if it is usually cleaned of salt after it is used.

As noted, Lewmars have a very fine non-skid pattern, and the prep and plating fill these in a bit so there is less grip. This can be problematic on bigger boats or on a winch that has many replatings or on a boat that has been in need of rechroming for so long that the non-skid pattern has worn through. The interesting thing is that on properly loaded winches, the chrome generally does not fail on the non-skid gripping surfaces of the winch but on the smooth top of bottom flat which of course means that there should be pletty of non-skid left during the first rechroming.

Jeff
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