What do you think of this method of bolt hole repair?

[Xist]

He drills out the stripped bolt hole, taps it for one size larger, degreases them, uses a center punch to ding up the threads on a grade 2 bolt, creating a burr and a lock thread between the threads on the top half of the part that will go into the hole, use Lock Tight, install the bolt, cut it flush, carefully grind off the excess, punch the center, and tap it for the correct bolt:

https://www.youtube.com/watch?v=Ykk0bP4DChE

[freebeard]

Sounds like a home-brew Helicoil

guidemanualjean99.z19.web.core.windows.net/helicoil-design-guide.html

[Xist]

Indeed, but a grade 2 bolt and a cheap tap kit are cheaper.

[freebeard]

taps it for one size larger, ... punch the center

That's a pretty small margin of error.