So I'm about to start on a piece for a friend, going to practice a bit first on some scrap of the same size/material, but there are two welds I'm just not sure about.

This is for a cooling fitting, lower radiator hose goes on each end. I need to run a bead around, to replicate the flare on the original. Not a big deal, surface, no through penetration needed, just keeps the hose on, but it does need to be the same distance all the way around.

I thought about making a fixture for the torch and then rotating the piece on it's own fixture, but it seemed like a PITA for two welds. Started thinking about the best way to mark it so I could follow it visually, but was concerned about introducing anything into the weld area. What should I use to mark it, a nice scratch, soapstone, sharpie... something else? Or do you think it's not overkill to fixture it and rotate the piece and manipulate the filler under a fixed torch?