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While in Oz, I got myself 5 sets of lugs to build myself some frames for my daft experiments.
I fancy trying bonding one with epoxy or similar.
If I remember right there's a few experts on epoxies and chemical bonding on here.
Will it work, or won't it?
So fire away... 🙂
Can't see why not.
I quite fancied having a go with carbon tubes. Buy some oversize off cuts and pre-preg ribbon to make the lugs and get some tubes made.
Raleigh used to use Permabond single part epoxy for their Dyna-tech frames.
Getting suitable lugs, bottom bracket shells etc would be your biggest problem.
It worked for the original Dynatechs and you still see them around 30 year later.
My one concern is the total area for bonding.
The Raleigh lugs had far more surface area than the lugs used traditionally for brazing.
Was that just playing safe or necessity?
(It will be steel on steel, so not dissimilar metals)
Didn't the lugs also have reinforcing on the outside, maybe to reduce flex if the glue joint.
In principle there's no reason why not, there will be a glue that works.
You might need to etch prime before bonding, some of the glues can do this if not it's another process.
I think the main issue you'll have is that lugs are designed around standard tube sizes, with a minimal gap to create the capillary action that draws the silver solder through the joint.
Most of the glues will want a 0.2mm (some larger) all-around gap to maximise their strength - an eccentric glue joint could have a significant effect on the bond strength.
Some of the glues will also want to be post cured.
Say for example that you had some lugs similar to these.
(Haden, Made in Birmingham .)
You would be wasting you time trying to glue a frame together with those lugs.
But you could use them to make a frame by brazing / silver soldering with those lugs. That is if you wanted a frame that is based around: a one inch fork steerer tube (1 1/4" headtube), one inch top tube, 1 1/8" seat tube and down tube. Plus you will need to braze / silver solder the seatstays and chainstays, dropouts, brake bridge, cable guides, stops etc.
You can get tubes from Reynolds
The, Reynolds META-BRAZE Fillet braze wire - AG 40% , silver solder from Reynolds works well with the META flux.
Or Columbus tubes from Ceeway.
https://www.youtube.com/watch?v=u94WsKf6JRo
https://www.youtube.com/watch?v=JHAuqvR26qk
https://www.youtube.com/watch?v=fJHBYGo_F-c
https://www.youtube.com/watch?v=XMWz0PmtWCM
Various frame building courses exist. The advantage of going on one of these courses is that you should end up with a useable frame at the end.
https://www.ellisbriggscycles.co.uk/framebuilding-course/bicycle-frame-building-courses-pricelist/
https://thebicycleacademy.org/
https://www.bicycles-by-design.co.uk/frame-building-courses/
http://www.geoffrobertsframes.co.uk/frame-building-course
https://www.reillycycleworks.com/pages/frame-school
Thanks for the info paton, but not looking to do a course. Just need to get my hand back in and it's cheaper to bugger up a few attempts than travel all the way down south, pay for accom plus a course.
The question of sufficient area is a factor in my thinking, but I think mogg makes the most pertinent point, ie bonding usually requires a larger gap than lugs designed for brazing.