All was going according to plan. I carved, and I enjoyed it.
When I was finished I sat the letters on top of my bookcase for a while to enjoy them.
Then I made some latex moulds of the letters. I painted on twenty coats, which took two weeks allowing for drying time inbetweentimes, and really ponged.
Possibly the mistake came in slathering a load of plaster over the top of the whole lot to make a 'mother' to support the latex while casting, because here's what happened when I tried to get the whole lot apart:
I had to pull so hard on the latex to dislodge it from the mother and the original letter that it distorted unusably.
...and I destroyed my letters too. Waaah!