black flux, more silver, cotton gloves, one temp. crayon shipping tomorrow from Airgas Reading. the black flux is what i'm really waiting on.
i tried another couple brazes today with a technique recommended by Chris at Circle A Cycles in Providence. i found out about them from a messenger buddy at work; i'm planning to visit when i go up to tour RISD.
he told me to split a tube lengthwise and wrap it around a length of same-size tube, and braze it like a split lug. this worked pretty well, except that there was a part where i think the gap got too big and silver didn't flow. my furniture teacher (who's one of a couple good brazers at school, both otherwise wood people) helped, directing a propane-air torch up through the tube, giving some nice even heat while i provided more focused heating with a pretty big, wide oxy-acetylene tip. i had the fan blowing from the same direction as the propane torch for ventilation, which made the tube into a little blast-furnace typea thing.
i tried to do the same furnace thing later on, but i had the lights on and the torch adjusted poorly so it overheated quickly and the flux burned off quickly.
bending the other day was not successful. the plywood split along the plys with the 90° v-groove cut into it, so i reinforced with 1/4-20 bolts just under the groove. that took a while, and even then i wasn't able to get the bends i wanted. i got one blade curved nicely, but in doing so i kinked it with the solid round cheater bar. that one i bent first on the 8" radius bender, then on the 6"; i tried to start the second blade on the 6", but then it kept popping out of the hold-down bit when i tried to switch to the 8". the second time that happened i called it a day, figuring things were getting a little unsafe.
i'm working on getting new blades and outsourcing their bending. Bringheli's Deda ZeroTres will likely be the winners, but they may be a bit short for the brake reach of the Dia-Compe centerpulls (70 mm). so maybe the pads will sit in the top of the slots, or i'll dig up some shorter centerpulls.
more on the school front as well: i'm planning to take a tour next week of the shop at CVCC, a comm. college in SW Virginia offering an Associate's in Machine Technology. i found out about it through this list of schools offering CNC instruction. i'd been looking for a list like that for a while--it's given me some hope that there are schools out there (actually, nearby) that have programs i'm interested in.