yonekura

Well today my housing got snagged on a handrail, and the end result was this housing guide broke. it was never strong to begin with since when I got the frame this particular guide was partially crushed.

I have looked online and the braze-ons, and they are not too expensive. However, I don't have an acetylene torch. Can I use propane or mapp gass to braze a new guide onto the frame. I suspect I can't use brass brazing rod with a propane or mapp torch. I just want to fix it without spending too much money. I can get a powder coat for 90 dollars.

Andrew R Stewart 

For this small material mass job a torch that's inadequate for BB shells and crowns can be fine, like MAP. I would strongly consider a lower temp filler, like 56% silver brazing rod.


I would consider removing the other not yet broken casing guides and attaching split casing stops. Andy.

yonekura

I actually was curious about what's better guides or stops.

Andrew R Stewart 

I'm a wrench so the design that allows for easy maintenance is the better choice IMO. Andy.

unterhausen

I would use a clip unless you were really set on ruining the paint

FBinNY 

Since a housing guide is non structural and has minimal load, I'd consider carefully filing the old one off to not quite flush with the tube. If you're good with a file, you can get as close to flush as you dare, but want to be careful about filing or cutting into the tube. Then shape the back of a replacement to a good fit, and glue it in place with high strength adhesive.

There's no sense in burning the paint with a silver solder repair at this point.

BTW - If you want more strength than you think glue can offer, start the same way, and drill a small hole into the tube. Then drill the back of the replacement, and set a pin, silver soldering it, which is easy enough with MAPP gas on a part this small. Then clean everything up well, and set the replacement using glue.

yonekura

Well filling off the busted guide means steel is exposed, plus there are a few other rough patches so I am not sure that would be the best course of action.

unterhausen

nuking it with a torch means a whole lot of steel is exposed.

But I have no idea why you would do anything other than use a clip

FBinNY 

You asked about brazing a replacement. How do you propose to do that without first removing the broken one? And how do you expect to braze anything without burning paint and exposing steel?

Either way, you have to get down to a clean tube, ie. debraze, then cool, and clean up with a file in preparation to brazing the replacement. hat's two heating cycles. All I'm suggesting is that you remove the old one with a file instead of heat, then once you're down to the tube (which you are not filing) you can either braze or glue the replacement. Your call.

Off course you might carefully clean up the existing braze on, filing the broken bit to the base. Then buy a new braze on, carefully cut it in half to match what's left of yours and then silver solder the new top to the old base.

That's possible, but it's delicate jewelry maker's work, and there may not be enough strength. But it's a viable option if you have the skill for that kind of delicate work.

All in all, I suspect that my clean up and glue approach is far less intrusive than any brazing solution, but it's not my bike.

FBinNY 

Ours is not to reason why......

fietsbob

for substituting guides consider zip tie anchor guides,
they really have nothing to break off but the replaceable plastic zip tie.





you could file off the sharp bits and just get self adhesive zip-tie attachment patches or just tape down the housing..






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