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Saturday, 8 February 2014

Internal Cable Routings - Technique Sorted!!!

One of the many things on the list for today was to finish Taylor's internal cable routing's. I had already formed the internal tubes (using my new "mini" bender) so all I needed to do was to braze them in place, fettle them back and then braze on the strengthening surrounds.

I learnt quite a bit about brazing internal routings whilst on my honeymoon a couple of weeks ago - the major lesson being to use silver solder to fit them in place and not regular brass brazing rod like I had in the past.

The reason for using silver is that its melting point is considerably low compared to brass (630-660 deg C compared to 870-809 for Sif 101 brass).

Perhaps unsurprisingly in hindsight, when I did the internal routings on my first frame I had a complete nightmare - the brass internal tube kept melting away! The reason for this is that I was using brass filler rod which melted at the same temperature as the brass internal guide tubing - fail!!

Using silver filler rod was like cheating - it made what had previously been quite a daunting process into one which I now can;t wait to do on a future frame!!

So, to summarise, I used Sif solder number 43 and the Cycle Design Stainless Light Flux paste - don't forget this flux simply dissolves in hot water.

Clean
I will be leaving the internal routings on my next bike like this - super clean.

And here is the brazed on strengthening surround piece - nice!

The last lesson I learnt today was to make sure the oxygen valve is open on your oxygen tank before you start to braze - I had just enough oxygen in the lines to get going and then this happened - messy!!




On the cards for tomorrow is finishing off the brazing of Taylors front triangle and then I need to get on and shape the seat and chainstays for both bikes.

2 comments:

  1. 'I learnt quite a bit about brazing internal routings whilst on my honeymoon.......' You must have been a bundle of larfs for Mrs DMO ;-)

    ReplyDelete