Ti chainstay coming out of lug dropout repair.

[mattr]

The plug is an impressively long, but very smooth forging, and the bonding surface to the aluminium appears to have failed, rather than a deterioration of the adhesive itself.

this is not actually uncommon for a joint like this. Degradation of the base material. Lots of work/research been done to find ways to protect the metal under the adhesive and prevent corrosion/attack by the actual adhesive.

 

[CTK]

Really happy with that! & thankyou for taking the time to photograph it.

 

[danson67]

The plug is an impressively long, but very smooth forging, and the bonding surface to the aluminium appears to have failed, rather than a deterioration of the adhesive itself.

this is not actually uncommon for a joint like this. Degradation of the base material. Lots of work/research been done to find ways to protect the metal under the adhesive and prevent corrosion/attack by the actual adhesive.

It does seem to be predominantly the aluminium plug side that fails, rather than the Ti tube surface, in these cases.
Weird, given the relative differences in hardness, surface finish and reactivity, which would all seem to favour a better bond with aluminium that Ti.

Maybe thermal expansion/contraction differences? Same material designs (such as the Vitus 979) seem less susceptible. Also the tubes there are anodised, while the lugs are bare... :?
Presumably more to do with relative galvanic corrosion scale (where Ti and aluminium are polar opposites),

rather than straight material reactivity (where Ti and Al are pretty close).


All the best,

 

[drcarlos]

I've seen a lot of 80s/90s aluminium caravan walls corrode due to the adhesives used. They corroded from the inside out resulting in holed outer panels that looked a bit swiss cheesed. Obviously in this situation a permanent repair is almost impossible as it would involve replacement of a whole wall.

As for metals in the red section I've seen lithium fizz and dance around on the surface of a tank of water and Cesium reacts so violently it was dropped with the dropper at a distance and blew the tank to pieces.

A nice save though. Frame looks quite funky too.

Carl.

 

[Tad]

Re: Re:

Lovely work and a v. Satisfying read.

This. Always an education.