In the latest experimental (15702-gaac586e) the integrated toolset no longer appears to be a valid welding tool when constructing vehicles.
It still works fine in normal crafting.
I did a little more testing, and can confirm the problem exists in Windows tiles version: 0.C-5104, 0.C-5103 and 0.C-5102. The integrated toolset can be used to weld vehicles fine in version 0.C-5101.
I tested by starting a new game as a bionic prepper, and finding a car to check the menu. In 5101 it requires a “powered welder”, which shows up green with the toolset. Whereas in 5102+ it requires “welder (50 charges) OR makeshift welder (75 charges)…”. Might be related to whatever made those changes.
you guys are confusing ‘problem’ with ‘feature’
Doesn’t sound intentional to me. Toolset is allowed everywhere welder is.