I started my last trial with gel coat. As always Kemal Abi didn’t do what I wanted. He suggested to wrap a ball with tape and cover it with gel coat. I begged him not to waste time with it, he didn’t listen and of course it failed.
Then I got minimum help from Kemal Abi, learnt how to use plaster and gel coat did it own my own.
After the gel coat dried I had to be quick to empty the plaster inside it.
This is what it looked like after 1 hour.
And after 2 hours I managed to cave this path.
After 5 hours it was done.