buy the good rare earth magnets from Lee Valey, the use an acrylic epoxy potting mix from industreal plastics and paints.

Steve

OK I like the encasing in epoxy/putty idea, it will also make it simpler because I can add the filter clip holder (the U-shaped part that attaches the filter pipe to the suction cup) into the epoxy at the same time.

Was thinking this through a little more, you'll have to do this in 2 stages, lay a bed of epoxy on some wax paper, give it a little scuff once dry to ensure adhesion. Lay the magnet on, cover it over with epoxy.

If you bypass the scuffing part - those tiny dixie cups they hand pills out in (about 1/2" diameter) would be a perfect mold for this project.

Andy