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I want some braze-ons added to a 531 frame - probably just to the seatstays so i can fit a rack.
Is this possible with a disposable canister style blowtorch? looking at the gosystem site they advertise silver rods mentioning steel, and "hottest commercially available gas" etc - but is it ever going to work on a frame, or do i need to find someone with an oxy/acetylene set up to do it for me?
(tbh this is probably a good idea anyway, but i would practice first..)
anyone had any experience?
i have 'migged' a brake braze on to a 4130 cromo frame before, then just painted over it with hammerite, it was fine for a decade after that.
not sure i would be so cocky with 531 though, afaik its a fair bit thinner than a basic trek frame.
i suppose it depends on how heavily you're gonna load the rack up.
it could be worth giving the likes of argos a ring, iirc they didnt charge that much to do a braze on/spray job.
i suppose my question is whether it will get hot enough at all rather than whether it will damage the frame, which i think is unlikely - i know that's why silver is used for standard braze ons anyway..
with 531 id be more worried about getting it too hot, it affects the strength of the tubing by effectively undoing the heat treatment of the tubing.
BUT, im not an expert, hence it may be better to speak to one.
Bottle bosses silver soldered to 853 with propane blow torch. You need to get in and out as quick as possible.
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You'll struggle to braze, but silver soldering should be do-able. For eyelets on the seat stays that'll be fine.
I was going to give this a go, but found these racks and bought one.
[url= http://http://www.oldmanmountain.com/ ]Old Man Mountain Racks[/url]
that sounds promising. Can i confirm that silver soldering is similar to using lugs, as opposed to fillet brazing, or is there another difference there too? (once again, i'm going to do plenty of testing before i touch the actual frame!)
I've seen those racks before -they look pretty nice! but tbh the physical process appeals to me.
Silver brazing uses silver brazing rods - with the high silver content they melt at a lower temperature than brass. You usually use a different flux too.
Either can be used for lugs or fillet brazing, though since the silver rods are pretty pricey it's not normal to fillet with them.
you can silver solder those on no problem with a plumbers type butane blow torch, we do this regularly at work because the fire brigade/H&S wont allow us oxy acetelene bottles in the workshop!
silver solder rods and a good flux, do NOT forget the flux!
I use 55% silver and SIF flux. Melts around 650 deg and the flux is a pain to clean off but pretty easy to do.
nice one, thanks all!
We used that gas with brass rods to repair the rear triangle on a friend's Moulton - but you do have to get the steel to cherry red heat to melt the brass so for non-structural lugs on 531 I'd use silver.
Just in case you haven't looked the ceeway website is worth a visit with lots of lugs and brazing supplies