Use IG Cleaner (of course!)
When using our cleaners, you have to take the precaurtion not to get the cleaner "behind" a decal (inactivate with water).Of course the corollary is that yo can do this deliverately and it will not damage gelcoat.Put any of our cleaners around the ouside of the decal. Come back after a while (can even leave overnight, peel the edges forward and add som more cleaner. Eventuall all the adhesive becomes like goop. To make the surrounding gelcoat the same color as under the decal, use appropriate cleanser/conditioenr (SEA GLOW for white, blue red etc, CLEAR for beige, cream, brown etc.Have done this of pieces of hobie cat I used to take to Boat Shows. and once customer removed dried on adhesive that would not budge by other means. Unlike acetone does not damage gelcoat.How does this compare with WS40? I have found that WD40 (which has some light petroleium products) works better than IG on grey duct tape residue but that IG is better on decal adhesive residue. How does it work? THe original solvent in the adhesive of the decals is closely related to a compenent in the IG cleaners.ThanksJim Willis