Do you have access to both sides of the hole you want to drill? As in, is the T47 shell solid or does it have cut outs between the threaded sections?
Get some West Systems G-Flex epoxy. Most marine shops sell it, so does Amazon. If you have internal access, smear a very thin layer in the location of the hole before drilling. This will help prevent fraying as the drill bit exits the back side. Let the drill bit do the work. To much force will cause the drill bit to break through the backside rather than drilling through it and you'll end up with a lot of fraying. Once the hole is drilled, smear the epoxy around the edges of the hole to seal up the edges to prevent the possibility of water getting absorbed between the fibers. It doesn't take much, just enough to fill in the porous areas.
