yup tinning will work with shifter bosses by all means. Although these bigger braze ons with butane may take a while to get to temp, and your arm holding it in place may get a bit tired. What i want to stress mostly about tinning is that fact one is certain that both frame and boss have complete surface adhesion of the filler. That said, there is one Achilles heel to it, and that is after the melting temp has been reached, and one is letting it setup, any movement can be catastrophic to the bonding strength, and often without knowing. get comfortable when heating it up, and hold steady for atleast 4 or 5 seconds after removal of heat.