Cracked trunnion

[javithewrench]

I've read a few threads about cracked front trunnions over at the akfiles but I'm a bit chicken to post over there so I figured it post over here.
This is my very first build and I'm not sure if I cracked the trunnion or if it came that way, either way it's cracked. I headspaced the barrel and cut the new hole. That's when I noticed the crack, before I even pressed in the pin. Not sure if maybe the way I held it in the vise cracked it? Anyway I drilled the crack to stop it from spreading and I think it will be fine to use, what do you builders think? I can tig weld it but I think it's strong enough as is. I want your honest opinion and I'd like to save the trunnion since it's my first build and a matching numbers kit. Thanks!

[buellster]

What size did you drill the barrel pin hole?

[javithewrench]

Cracked trunnion

Used 1/4 end mill the reamed it to 7mm. Very slow, plenty of cutting oil and slight pressure

[buellster]

If it were a customer's I would recommend replacement. If it were mine I would assemble and tig a bead of weld over the crack and run it.

[Twystd1]

I would V groove the crack, then TIG, then run it like I stole it.

-T

[javithewrench]

For cast do I use stainless rod? I've welded cast before but never tig'ed cast

[Galt]

I don't know too much about tig but the trunion is cast steel, not stainless. I would think you would want to use a carbon steel filler rod to match the trunion.

[Bralowe]

As you've probably noted from reading about this issue, there are two opinions on this. One side says yes, one says no.

Personally, I'm not comfortable with welding the front trunnion in this area. I would opt for replacement.

[jericho89]

For cast do I use stainless rod? I've welded cast before but never tig'ed cast

cast is a pita to weld if you do not know what you are doing. Do a little study on what works best. Most preheat the cast metal first prior to even starting to weld it.

[NotEnoughGuns]

Cast iron and cast steel are two totally different animals. I would doubt a trunnion would be cast iron. Cast steel will Tig easily with steel filler rod. A little preheat would be best.

[Bralowe]

During the last discussion we had on AK Files, member allessenogwat, offered his researched opinion on the appropriate filler rod to use.

[javithewrench]

Cracked trunnion

During the last discussion we had on AK Files, member allessenogwat, offered his researched opinion on the appropriate filler rod to use.

Awesome on my way there now. Can't find it do you have a link?

[javithewrench]

Grooved it and threw a bead over it. Good enough.

[hellayella]

Grooved it and threw a bead over it. Good enough.

Haha, your welding expertise is put to good use!!

[Alex$]

pretty