Welding a cast trigger guard

[RU shooter]

I got my parts in from MBS yesterday for my next rifle but I'm going to eventually shorten the grip rail on the cast steel trigger guard as it's just a bit to long for my hand and the look I'm wanting when completed . Question is can these cast guards be welded with a mig welder ? I'm decent at welding regular steel and thin sheet but never done cast anything . Looks like a good casting not the real porous sand cast .

Tim

[elk hunter]

With MIG wire being copper coated you will have a color difference when you try to brown or blue the trigger guard. If it were me I'd first try to TIG it and if there were too many impurities for that I'd go to oxygen/acetylene. Depending on the composition of the cast and the filler rod you may still have a color contrast that would be hard to hide. You will want to make a fixture to hold the parts together and in position while welding.

Just my $0.02 worth.

[Soundguy]

I got my parts in from MBS yesterday for my next rifle but I'm going to eventually shorten the grip rail on the cast steel trigger guard as it's just a bit to long for my hand and the look I'm wanting when completed . Question is can these cast guards be welded with a mig welder ? I'm decent at welding regular steel and thin sheet but never done cast anything . Looks like a good casting not the real porous sand cast .

Tim

Cast iron is finicky to weld.. but cast steel welds just fine. I repair and rebuild antique tractors.. it's common for front axle leaves to be cast steel.. I've seen more welded than not welded.. never seen one welded twice. cast steel should weld fine.

I bet the weld union will artifact on bluing.. even if it is polished out so that it is not visible to the eye... the alloy difference will blue differently.

[rbuck351]

You say it is cast steel, so if it is cast steel and not cast iron I would use oxy/acetylene. I'm not sure how you would weld cast iron so it could be blued without looking like it was welded.

[waksupi]

I would recommend TIG.

[M-Tecs]

Matching the filler rod to the base material will give you the best bluing/browning results. Chances are if you use a uncoated mild steel filler rod you won't have any bluing/browning mismatch. Tig would be my first choice, oxygen/acetylene would be second with MIG last. Brownells sell a 3 1/2 nickel rod. The nickel makes me nervous about bluing but they say it's not an issue. https://www.brownells.com/gunsmith-tools-supplies/general-gunsmith-tools/welding/3-1-2-nickel-steel-welding-rod-prod594.aspx

Give MBS a call or and email to see if you can find out steel they are using for their cast steel. They also have iron ones but those will be wrought iron not cast iron. Wrought iron is very weldable.

https://www.muzzleloaderbuilderssupply.com/mbs3cart/agora.cgi?cart_id=8418929.11332&next=25&product=Triggerguards&user4=Investment+Cast

[Soundguy]

Nickel rod would worry me unless I was working cast iron.

[LAGS]

I gas weld all my trigger guards that are damaged ,either cast Brass or cast steel.
I have done bunches so far since I buy damaged guns and fix them up.
I don't want to spend a lot of cash fixing up some of the marginal or cheaper guns.
But I have also modified some guards to fit rifles that I built from scratch.
When polished and blued or browned , you can hardly see the repair.
Same with using Brass Brazing rod to fix the Brass Guards

[megasupermagnum]

If this an oversized cast part, meant to be ground and polished to final shape, I would consider TIG welding WITHOUT any filler, and simply fuse welding.

[RU shooter]

Thanks all with the advice . Not really too concerned with the blue, browning as I'm gonna scrub most of the brown back off anyways shooting for an aged worn look on the steel parts .