I use a rag soaked with isopropyl alcohol to get the majority of it off. Then I'll use a scrub pad soaked in alcohol to get the rest. It is hard on the hands, but it will get most of the Sikaflex off. I also use the white Sikaflex since it more closely matches my skin tone and I know that I won't be able to get it off my hands completely. :? You might try a clear silicone-based adhesive in the future. I've been using Marine Goop lately and I'm very happy with the results. It isn't perfect for every application, but it adheres well to polyehylene (if the surface is roughed-up), has good mechanical strength and cleans up easily.
Oh dear, I had a similar problem when I put the flush mounts in Squidette's yak, I ended up with black sikaflex spots on my hands for a week. I never found a good way to get it off, but resolved to wear disposable gloves when working with sikaflex from now on :wink:
I know here ya coming from PeterJ, there's guys like us who are just trying to put forward helpful suggestions...and then there's the others....guys like Occy...who hop along as they please like mindless bunny rabbits.... and then go about deliberately trying to change the whole tone of the thread. Off with the rabbits!