Protecting the surface of hydraulic cylinder rods is particularly important in corrosive environments, such as marine or offshore applications. And even more so if the cylinder rod is finished with conventional, hard chrome plating, which due to its micro porosity, has relatively poor corrosion resistance. The BEST way to keep the surface of the cylinder rod protected, is of course to park the machine with all of the cylinders fully retracted. But this is not always possible. And even if it is, if the cylinders are gravity loaded when fully retracted, it’s possible they will extend over time, exposing the rod.
One solution that’s extremely effective is to wrap the exposed part of the rod in Denso tape. Denso tape is a petrolatum (petroleum jelly) impregnated tape which is readily available from most industrial supplies merchants. The BIG caveat with wrapping a cylinder rod with Denso tape is if the cylinder is retracted without first removing the tape, it’s likely the rod wiper seal will be damaged. Also, when Denso tape is removed, it typically leaves a sticky residue. In the case of a cylinder rod, it’s advisable to remove this residue using a shop towel soaked in a petroleum based solvent before the rod is retracted. This will ensure the wiper seal is not compromised and that this potential source of contamination does not enter the hydraulic system.
An alternative to Denso tape, which doesn’t present the same potential risk to the rod wiper seal, is a product like CRC Soft Seal. This is a spray-on, petroleum based product that forms a dry, amber film which is resistant to humidity and salt spray. Once again, it’s advisable to remove the coating using a shop towel soaked in a petroleum based solvent, prior to putting the cylinder back into service.
Another practical use of Denso tape in corrosive environments is on hydraulic hose ends. Stainless steel hose ends are many times the cost of their nickel plated counterparts. But in marine or offshore environments, nickel plating only offers short term resistance to corrosion. As a result, when it comes time to replace the hose, the female swivel is usually seized solid. And this makes it frustratingly difficult to remove the hose. Wrapping nickel plated hose ends in Denso tape eliminates this problem, at a fraction of the cost of stainless steel hose ends. There is some labor involved in applying the tape, but it only has to be done once–and thereafter only when a new hose is installed.
Bottom line: failing to protect electro-plated surfaces such as cylinder rods and hose ends in corrosive environments can turn out to be a costly mistake. And to discover six other costly mistakes you want to be sure to avoid with your hydraulic equipment, get “Six Costly Mistakes Most Hydraulics Users Make… And How You Can Avoid Them!” available for FREE download here.