Framebuilders - Braze on removal questions - Fixed bike prep.

Hi Guys,

I won an old steel frame on ebay last week and I want to build it into a fixed gear bike.

My intention is to clean the frame up first and then powdercoat it.

I tried last night to remove some of the braze-ons on the frame and was successful in removing the TT cable guides only. I want to remove the DT shifter bosses also.

I only have a brazing gun - made really for jewellery. I'm thinking my brazing gun cannot get the metal hot enough to release the join. One of my best mates has an oxy torch - would we be better trying that out?

What do you recommend I do next?

Or would the powdercoaters usually be able to do it for me?

Thx in advance

Some people file off braze-ons. I use an oxy-acc torch.

What kind of frame is it?

What kind of frame is it?

probably a 1959 Cinelli previously worth $15000

If your frame is a no-name in lousy shape that cost you fifty bucks, your best bet may be to remove the braze-ons with a grinder and files. There is a school of thought which holds that it actually takes more heat to remove a brass-brazed braze-on than it did to braze it on in the first place, which is not very good for the tubes.

If your frame isn't a no-name in lousy shape then you've offended the cycling gods and will be struck down.

HTH!

pretty sure it always takes higher temps to undo a brazed or soldered joint than it did to join it in the first place. Undoing a brass joint thus would take you into a potentially dangerous temperature range. Silver is no problem. An older European/UK frame is almost surely put together using only brass.

Just to be sure i'm not offending the cycling gods...it's an old lugged 4130 steel Apollo and it cost me less than $50usd.

It is actually in great shape with no visible surface rust at all. We'll see though with we beadblast it.

From the advice from you guys, i'll be grinding them off tonight then using filling if we go too far.

Thanks!

please don't go too far. Stop early and get out the 80 grit emery cloth. Hate to see the cycling gods competing with Darwin to punish someone.

Ha!

Well, have fun, but yes, it's worth being careful. You can actually forgo the grinder entirely. A 12" bastrad (yes, I know how it's spelled, but the forum software thinks it's a dirty word) file will take off braze-ons shockingly quickly, and with significantly less chance of ugly holes in the tubes...

All done. Took it very slowly and we ended up doing a pretty good job i think. Took off all of the join and we'll just fill in anything that needs it.

I'll take some pics now and during the build.

Here's a pic of one of the shifter bosses after being ground. The paint is black around it from the efforts with the brazing torch which were unsuccessful

Here's some more pics...

So I ground off the down tube shifter bosses and the rear derailler cable guide. The brake cable loops on the top of the TT were heated up and removed with my braze torch

Some people file off braze-ons. I use an oxy-acc torch.
Other people just leave them alone if they're not in the way of anything.

Sorry to bring back an old thread, but I used this procedure and it worked wonders on my '62 Colnago fixie conversion. Thanks guys.

Sorry to bring back an old thread, but I used this procedure and it worked wonders on my '62 Colnago fixie conversion. Thanks guys.

Same here on my Confente and Spectrum.

-Kurt

Same here on my Confente and Spectrum.
Cool! I'm off to convert my René Herse randonneur right now!

Cool! I'm off to convert my René Herse randonneur right now!

Oh, that reminds me, I have a chrome Singer waiting in the basement. Thanks, John!

-Kurt

What's a '62 Colnago frame worth, $5000? Of course they didn't have any braze ons, so a restoration would involve removing any.

In a related note, could one of you please send me your old-braze ons? I just found this cool GT Pulse track bike that I want to convert into a roadbike and want to attach fittings to it.

jim

Try the nova online catalog, probably easier and cheaper at the end of the day.

I'm not convinced about the heat thing for the usual reasons:

1) you can weld most of the tubes out there so heats into white do not harm these tubes, under the right conditions. Abviously we are way below that level here, so in most cases there shouldn't be a problem.

2) if it is the kind of part like a cable guide where you can heat it up and let it conduct the heat to the braze in between the guide and the tube, then you should be able to get the heat in there without getting the tube too hot. However, if you do that, you might as well cut the BO and sand/file the lumps anyway. It pays to have a really hot heat source for this kind of thing since the heat can rise really quickly in the joint before it spreads far and wide. The colder the heat source the worse the heat contamination, but then if you consider 1) above it probably doesn't mater.

In a related note, could one of you please send me your old-braze ons? I just found this cool GT Pulse track bike that I want to convert into a roadbike and want to attach fittings to it.

I've got a pair of never-used braze-on downtube fittings, and can get you braze-on FD hangers.

-Kurt