hey guys have a spare boot on the way and am going to flush it.

what would you say the best way of welding it would be? have been told a way of tacking it on then doing inch long welds, or just doing it all the way round in 1 hit?

am going to drill 2 holes and put a small amount of expanding foam in each of them (mate advised me to do this) is this a good idea?

also if any of you have done a boot flush yourselves how did you do it and what do i need to watch out for? any advice would be appreciated