How to dish a tank - 1

SO I was having this old tank...full of resin, since the guy from who I've bought it for some reasons made it full of resin. Perhaps a leakage? anyway I've decided to test myself doing it dished..
first step I've sand it to raw

Then I've made a template for the shape to cut

and finally I've cut it and tacked ..

I will post some other pictures when I finished welding...