I haven't done it personally or anything, but I worked at a machine shop local here where Blocks etc. were welded by the local welder. It was usually torn down & hot tanked prior to any welding to ensure clean surfaces & no fire. Block is heated using an oven if possible, then welded with a nickel rod. You need an experienced welder, Ask around, the local welder here is about 80 & I am sure he has forgotten more than I will ever know about welding. Brian
