SWE said..
Gave the rails a polish and a very good wipe down with acetone.
NEVER, EVER, USE ACETONE ON EPOXY !!!
It can actually soften the epoxy (you will notice it as it "clouds" clear epoxy), and will create invisible micro-cracks in the epoxy, (epoxies have additives such as anti-UV ones that can be dissolved by acetone, thus leading acetone inside the material), weakening the rails that can then ding more easily or leak water. Use less agressive solvents: I use "Solvent F" to clean greases/oils, then alcohol to clean the rest.