Quite an Unusual one

[Neale]

A good way to seal the leaks around a dam before you pour your epoxy is to make up a very small amount of the epoxy and using a small brush or similar just go round the inside of the dam brushing the epoxy into place. it will run into the holes or bridge the smaller holes but because there is not a large quantity behind it, will not run right through and leak out the bottom. You only need to leave it long enough to stop flowing easily before you pour the main epoxy batch - you do not need to leave it for days to fully harden. I made my dam from gaffer tape, stuck to the sides of the rails so that the edge of the tape was above the rails. Biggest problem was peeling it away from the epoxy when the epoxy had hardened. Next time I shall try pulling it away before the epoxy has fully hardened!

I had to strip my first load of epoxy off the rails and start again, but I had already drilled the rails. I put small pieces of Sellotape over the holes and poured the epoxy over the top. I could see where the holes were and then just drilled through the epoxy after it had set. Worked for me!