So I am am going to be welding up an exhaust manifold (cast iron) and was going to order either Tech-Rod 99 or 55 or something similar and was wondering which would be the best to use for welding a bolt handle. I have a classic AC/DC Red Tomb Stone shaped Lincoln Arc Welder. It is too easy to add a pound of another item to the order to save on shipping latter on. I would instinctively go with Tech-Rod 99 since it is 99% Nickle and cleans up much easier and is much more machinable. That level of nickle though would be an issue if you tried to blue it. I was wondering if even 55% Ni would be problematic as well?!?!?!I am assuming it too would be an issue. Oh I also have OA or O/A gear so I could go that route too. I do not have TIG or I would surely use TIG. Either way I am not sure what alloy I should look for in the filler to make sure I have the option of blueing later on should I want to blue it or another owner down the line? Thanks guys! The more I ask this the more I think I should go the other direction and go for a general rod and look for silicone content to make it friendly with dissimilar metals and such! I feel like a dog chasing my own tail! LOL Thanks guys!