Thanks Dennis, What a good idea, to reinforce the die for multiple uses.

Thanks Nick, yes, the sand (which I don't currently have) would be a last resort as I really wanted a hollow form - if I can get it right I'd make a few - casting would be simpler of course, but I'd like to persevere with the hollow form.

I think I'm stuck now anyway for a few weeks, as it's the hols now and I have limited equipment/tools at home.

Sue
Sue