by Bluey » Tue Aug 14, 2007 9:22 pm
SeaMonkey,
There is very little limitation on the types of surface that can be Nickeled with proper cleansing. With steel we usually applied it to a ground surface that was electrolytically cleaned, changing the polarities every couple of minutes to remove any oily substances.
There is no prior copper coating. I checked with Google and today they have availabe further additives to increase hardness to around 70Rc and to further inprove lubricity.
In our application, hard chrome was used in reclaiming many components PROVIDED they were reciprocating and not just spinning. Chrome has very low lubricity and very low coefficient of friction, therefore it does not want to hold a lubricant and will usually seize if there is no axial movement to distribute the oil.
With the nickel being fairly lubrous we found that we could reduce the diametrical clearance by a half micron or so on what Steel to Steel would tolerate and not have seizures but on some engines we got improved starting. After spending about $25,000 on precision machinery etc. some idiot introduced CNC machinery and also decided to produce the new items in low cost countries and their prices halved.
I DO NOT KNOW IF NICKEL WILL IMPROVE COSTS OR PERFORMANCE IN ANY WAY SO BE CAUTIOUS. But if you do want to try a nickel coating you can certainly get this stuff VERY HARD, and it applies much more evenly than with electrolysis and will apply a uniform layer in every nook and cranny where-so-ever the fluid can get. It is really only suitable for comparativly thin coatings, at the rate of one thou per hour.
Regards Blue