In a never ending attempt to make the installation of air chambers (canoe) as painless as possible I tried masking tape around the circumfrence of the chamber while fairing it into place. The result was about 2 days of hand sanding trying to remove it from under the hardened epoxy. I now use a painters knife to apply and finish off the thickened epoxy. I like a really small fillet around the chamber and everything I tried up until I tried the painters knife made a wide ugly fillet, the tape being the worse attempt however. Doug