The reasons this is not recommended are well know however in as much as these are VERY expensive pats I'm wondering whoever has attempted this successfully and if so what was repaired and how?

 

Seen many threads on J-L about the theory and possible technique of repair, I recall none regarding outcome. The advisability of repair clearly depends on the unstated reason it is needed , perhaps the repaired frames got the repairer to the scene of the crash.

 

The front engine cradles on the E-type are made of a special Reynolds square-section tube made of their steel alloy called 531. Normal welding is not possible with this alloy, so all frames made by Jaguar were bronze welded, (note - NOT brazed). Reynolds 531 tubing is no longer made and new steel-based alloys are now used. New frames made by Jaguar specialists like Martin Robey use a different alloy, with the same square section and are bronze welded like the old frames.
The big problem with repairing these frames is that like all steel items, they rust and the rust is always on the inside, so unseen. Over time, this rust can seriously affect the strength of the frame, and this rusting on the original frames will have had 50 years to do its worst.

https://www.ebay.co.uk/itm/144804451...saAu0wEALw_wcB

https://www.martinrobey.com/jaguar/e...ne-side-frames

https://rexarc.com/blog/difference-b...based%20alloys.

 

Good articles especially the explanation on brazing.