i have a job of tig welding 1 1/4" round s.s. ornamental tubing on top of 1 1/4" s.s. square tubing for the top of a handrail. we shaped the square to fit the round tightly.the horizontal welds are no problem but when we weld the underside of the round tubing it pulls it down on both sides,looks like **** cause it will be up & down the entire length. i don't necessarily have to weld the underside but i do have to seal it.any welding tips or liquid metal? i refuse to use cilicone.