The great recycling LIE

[Cliffh]

Nothing you said there is doable.

None of it?  What's the difference between melting a welding rod to fill a hole and melting a narrow piece of steel to fill a hole?

If the flame is hot enough to melt the base metal, it'd be hot enough to melt the filler material - which would be the same material as the base metal.  I've filled more than one hole in various materials using both a standard arc welder and oxy/acetylene.

[Declaration Day]

I'm a steel fabricator.  I'm well aware that the finish after a welded hole is milled will not match the rest of the part perfectly, but a 2" Scotch Brite disc in a 90 degree die grinder can convincingly cover up a lot of sins.

[Declaration Day]

This. Before the enviros and before disposable society, this was SOP. I'm sure many here have anecdotes about parents or grandparents saving and reusing all kinds of stuff.

My maternal grandmother wasted virtually nothing. She survived the Great Depression and the rationing during WW2.  I remember as a kid, she grew all her own vegetables and fruits. She taught me canning.  She wasn't a smoker, but there was an ashtray on the front porch. She used ashes to scrub pots and pans. Dishwater was collected in a sink tub to pour around the roots of her fruit trees, because it would deter pests. Anything that was not edible for humans but was still food went to her dogs, like bones. I remember her throwing in the trash no more than one standard plastic grocery bag full of waste per WEEK!

[zxcvbob]

None of it?  What's the difference between melting a welding rod to fill a hole and melting a narrow piece of steel to fill a hole?

If the flame is hot enough to melt the base metal, it'd be hot enough to melt the filler material - which would be the same material as the base metal.  I've filled more than one hole in various materials using both a standard arc welder and oxy/acetylene.

It's been several decades since I studied this stuff, but I assume because the weld won't be shielded like it would from the coating on a welding rod or the gas in MIG welding.  If you do use oxy-welding, set the torch for a slightly reducing flame and you'll get some protection.

Are you going to heat treat this when you are all done?  If not (you probably know this) whatever welding you do to fill the hole will ruin the temper of the blade.  Maybe that doesn't matter right in the middle.

[Cliffh]

I'm a steel fabricator.  I'm well aware that the finish after a welded hole is milled will not match the rest of the part perfectly, but a 2" Scotch Brite disc in a 90 degree die grinder can convincingly cover up a lot of sins.

In a previous life I was a weld inspector* at a naval shipyard.  Not so good on the welding part, (my welds hold what they need to), but I still remember what a good weld looks like, inside and out.

*Mag particle, dye penetrant & radiography mostly.

Who knows, maybe the filled in mounting "star" would look good enough to be a trademark.   

I figured a heat treat would be necessary.  Heating the center to welding temps is going to change things.  Proper heat treating would be part of the learning curve.