Weld filler rod suggestions

[11Bravo]

Hello All,
Here is the project, a side lock with a sear that lost its nose, about 1/8" broke off. I know I could make a new sear but being a long time Tig welder I thought to build up the end with weld material and see if it works. I can't decide which filler metal I should try, 70S which is steel or 309 Stainless or what I was leaning towards Silicon Bronze (no heat treating). Any thoughts
Wayne

 

[BJHabermehl]

Hello All,
Here is the project, a side lock with a sear that lost its nose, about 1/8" broke off. I know I could make a new sear but being a long time Tig welder I thought to build up the end with weld material and see if it works. I can't decide which filler metal I should try, 70S which is steel or 309 Stainless or what I was leaning towards Silicon Bronze (no heat treating). Any thoughts
Wayne

Your best bet would be steel, after shaping the welded tip case hardening would be necessary

 

[PhDBrewer]

I have struggled with the same situation.
I know I can add hardenable metal to the sear nose or other parts with a TIG. However, nothing for filler is available but mild steel. Therefore, case hardening the part afterwards is the current solution.
I played around with the idea of making filler rod from 1075 or similar metal. Still might try that route at some point. Many antique parts are in need of a little filler to build up a worn area.
Please let me know what you discover.
William

 

[Kansas Kid]

4130 rod or hastalloy W.

 

[PhDBrewer]

What is 4130 rod? I have 4130 metal but no filler rod as such.
Or hastalloy?
For filler rod I found this blurb....
<Quote>
ER80S-2 is actually the closest match for tensile strength and required ductility for welding 4130. ER70S-2 is most commonly used and totally acceptable. Some weld procedures require 4130 filler, however, Using 4130 filler REQUIRES annealing post weld.
< end >
... and I have not an expert but willing to learn.

Thanks.