Spinlock's RP25 Coating is a chemical with a low viscosity that penetrates the outer cover coating all the fibers as it goes on into the core bonding the two together. This action not only assists in preventing cover-to-core slip by 10% (critical on Spectra, Dyneema and Vectran cored ropes) but also improves resistance to both internal and external abrasion by 40%.
The greatest gains are in preventing cover-to-core slip in the clutched area of a line, which is often misinterpreted as stretching of the line. A number of Vendee Globe entries are racing with RP25 on the critical areas of their lines and strops where abrasion risks and cover-to-core slippage are highest, e.g. - at mast sheaves, foot blocks, clutches, genoa cars, mast exits, lazy jacks, steering cables and furling lines and report great results.
To prevent slip, RP25 needs to be applied where the clutch mechanism contacts the line. Applying beyond the clutched area of the line does nothing to reduce slip. A two foot long application is more than enough (just make sure you know your measurements so you can locate your clutch in the middle).