Today I made a start on fitting a fin to bulb. The best tool to form the rebate in the lead bulb would be a very expensive milling machine. Alas I made do with a pillar drill, fein multi tool and a glass of wine!
I found the CoG of the bulb by balancing it on a kebab skewer. This mark would be where I'd drill the bulb for the bulb fitting bolt. On one of my existing fin/bulbs the fin leading edge is further aft and closer to the bulbs CoG, I'm currently of the opinion that this puts additional twisting pressure on the fin so I'm experimenting with a more balanced partnership.
All waxed up
West Resin and micro ballons