Advice on overcoating coppercoat please.

[Hydrozoan]

This sounds like a desperate measure to get something to stick to an epoxy that would not anomaly do so.

Applying ANY product over Epoxy that has not fully cured and been then abraded is madness and may even contaminate the lay-up. ...

When we applied two preventative coats of Blakes (later Hempel) Gelprotect SFE200 about 10 years ago, minimum and maximum overcoating times were given, with abrasion required only if the maximum times were exceeded. The datasheet here http://www.boatpaint.co.uk/datasheets/Blakes/GelProtect.pdf
gives the min/max recoating times for two temperatures. We have had no adhesion problems.

BTW, and please excuse the drift, has Hempel now discontinued the product or does it go under another name/number? One still sees web advertisements for Hempel Gelprotect SFE200 but I could not see it on their current product list.

 

[macd]

almost nothing will stick to Epoxy, a bit like silicon.

Sorry oldsaltz, but that's just plain wrong. Painted finishes stick perfectly well to epoxy, proving the surface is properly prepared and primed (so much like any other type of surface). There may be a problem, alluded to elsewhere, if a solvent-based epoxy is overcoated before the solvents have totally evaporated; there may also be a problem if the epoxy has developed an amine blush (usually through being applied in over-humid conditions), in which case it will indeed behave something like silicon (which I hate as much as you, if memory serves).

Just a couple of sources re over-painting epoxies:
http://www.westsystem.com/ss/finish-coatings/
http://www.glen-l.com/supplies/pxman-finishing.html