Welding
Mart,
I think the problems with weld stress cracking is related to thick weldments (1/2 inch or thicker).
For thin sheet, the metal simply yields until all weld stresses are superceded by the normal service loads. Thin welded structures are used for the most highly stressed parts. Look at the center fuselage pylon on the Enstrom for instance, welded thin tubing.
The alternative is bonding..... joint strength maybe 3000-6000psi.
And a welded 4130 joint is ........ 70,000 to 90,000 psi.
I like to weld..... dont trust my skills at bonding.