Welding a nut onto a snapped bolt

whats the best technique to mig weld a bolt onto a snapped bolt. As per my other thread I snapped a bolt off in the thermostat housing on my 200tdi defender 90.

Sounds like a stupid question but I had a practice on some old bolts but the weld doesn't seem that strong. It only contacts the top of the bolt. Someone on another thread said to drill into the top of the stub to increase the surface area.

Would an over sized nut work best? Means you could get weld around the stub as well as on top. Found the best result with max power and slow wire feed

Do you think the stud is stuck in housing, or in the thread, if it's the former you will need to consider destroying the housing, does help if you can weld close to a stuck thread, so heat can penetrate thread and ease movement, make sure weld is cold, and then rock spanner to create movement,( tighten/ loosen, tighten/ loosen)

if you have little thread or bolt protruding weld a repair washer on first then a nut

jamesmartin said:

if you have little thread or bolt protruding weld a repair washer on first then a nut

Click to expand...

What's a repair washer James?

payydg said:

What's a repair washer James?

Click to expand...

I always understood them to be the same as a penny washer, ie big uns with little holes.