Re: [CR] Removing braze-ons

(Example: Production Builders:Pogliaghi)

Date: Thu, 15 Oct 2009 20:21:53 -0700
From: "verktyg" <verktyg@aol.com>
To: Ken Foster <kenf3@me.com>, <Classicrendezvous@bikelist.org>
References: <9C5C523A-5DE2-48B3-A905-75CF6CA0F823@me.com>
In-Reply-To: <9C5C523A-5DE2-48B3-A905-75CF6CA0F823@me.com>
Subject: Re: [CR] Removing braze-ons


The problem that you can run into trying to remove braze-ons with a torch is that the remelting temperature of the brazing material is usually much higher than it's original melting temperature.

The melting temperature for most copper/zinc brazing materials is between 870°C to 980°C or 1600°F to 1800°F. The Critical Temperature of Steel is around 724°C or 1335°F. So it's easy to overheat thin wall steel tubing trying to remove braze-ons.

I've watched frame builders do it but they have a lot of experience working with thin walled tubing.

You could grind away most of the braze-on and then quickly remove the rest with a torch.

I remember playing around trying to remove some braze-ons from some old wrecked gas pipe frames to reuse them. It was a bear to get them off as the remelting point of the braze material was so high.

Chas. Colerich Oakland, CA USA

Ken Foster wrote:
> A couple of weeks ago (BFC) I recall someone asking the best way to
> remove later braze ons (dare I say, including a derrailleur hanger). I
> have a similar dilemma and was surprised there were no replies on the
> group and wondered what the consensus was grind them or burn 'em or will
> it cause irreparable weakening
> btw when finished it will have one brake. as in the original 1952
> catalogue...
>

> Thanks

>

> Ken Foster

> Eastbourne

> England