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...to do it right, you'll have to pull the stem, seatpost, and bottom bracket. NOt a ton of work, but yes, it makes more sense to do it when the bike is stripped . I use this stuff, and spray it in with a red plastic nozzle straw, so I can usually get the fork legs and the seat stays through the tiny hole left for expansion during brazing. They sell it at Home Depot here in the paint aisle.