Hi !
I'm a seasoned bike mechanic but I know nothing about frame building.

There a TIG welding co-op that popped up near where I lived, they teach courses and you can use the shop if you're a member.

I would really love to build my own frame, but I think I should probably start a less ambitious first project.

Basically, I'm wondering if it's possible to TIG weld some tubes on my old bianchi CX frame to reinforce it ?
If I have a rear rack load, the bike becomes pretty unstable and a bit scary to be honest.
The reasons for this is that the frame is quite tall (long tubes) and that it only has a slightly OS downtube.

I've seen double top tubes in Mexico... would that help ?
Or a tube that connects the DT and the ST ?
What about the rear triangle ?

Thanks for any ideas !