What filler rod to use?
Moderator: Harold_V
What filler rod to use?
I'm going to have to weld a cast iron piece and some 1018 steel together. What filler rod should be used and are there any special procedures that need to be followed? I'm set up for TIG.
Thanks,
HJ
Thanks,
HJ
Re: What filler rod to use?
Informed response requires intended mechanicals and thermal gradients.
What purpose does the weldment serve?
What purpose does the weldment serve?
Re: What filler rod to use?
The cast iron piece is bored to accept a "lightly" pressed shouldered cylinder. The blueprints call for 4 stitch welds to lock the pieces together. I believe the welds are there to prevent the cylinder from being "unpressed".
HJ
HJ
Re: What filler rod to use?
Without further comprehension on my part, stitch welds on cast iron are very poor practice.
The reason, rapid chilling guarantees cracks.
Yes, there are procedures to avoid that
But alternate methods may be preferable...anaerobic lockers, mechanical (pins, dutch keys etc.)
If the part is not greatly stressed in withdrawl you could "weld" it with silicon bronze and TIG.
Hard solders would also work...no stress risers.
But then you couldn't have a press fit unless you provided a "key" (like an annular groove)
The reason, rapid chilling guarantees cracks.
Yes, there are procedures to avoid that
But alternate methods may be preferable...anaerobic lockers, mechanical (pins, dutch keys etc.)
If the part is not greatly stressed in withdrawl you could "weld" it with silicon bronze and TIG.
Hard solders would also work...no stress risers.
But then you couldn't have a press fit unless you provided a "key" (like an annular groove)
- warmstrong1955
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Re: What filler rod to use?
Especially true with TIG, as the heat is more concentrated than with MIG, or especially stick. .Carm wrote:Without further comprehension on my part, stitch welds on cast iron are very poor practice.
The reason, rapid chilling guarantees cracks.
Yes, there are procedures to avoid that
But alternate methods may be preferable...anaerobic lockers, mechanical (pins, dutch keys etc.)
If the part is not greatly stressed in withdrawl you could "weld" it with silicon bronze and TIG.
Hard solders would also work...no stress risers.
But then you couldn't have a press fit unless you provided a "key" (like an annular groove)
If you do weld....
Get some nickel filler rod. Best chance at not cracking along the cast iron as it cools.
Preheat the parts after assembly. About 400-500 degrees should do it.
You will need to preheat it evenly! I've often used an oven for small parts.
Weld, and immediately stress relieve after each bead.
Stress relieve all the beads again after welding. Peining with a dull slag pick will work, but a needle scaler will work a lot better. Small beads, you can remove some of the needles so you don't beat other things to death. An air regulator helps too, for delicate work.
Cool slowly, and pein occasionally as it cools. You can do that in the oven, or, preheat a bucket of floor dry, and stuff it into that. Or....both.
Bill
Today's solutions are tomorrow's problems.
Re: What filler rod to use?
What about silver soldering? Is that what is meant by "hard solders"?
HJ
HJ
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Re: What filler rod to use?
I don't have any posts here so I probably have zero credibility but I do have 40 years experience as a welder so here goes. I would weld it with the TIG process using silicon bronze as filler rod, this would work best for dissimilar metals, which I do a fair amount of. If you don't have TIG capabilities I would stick weld it with 316L or 308L stainless steel electrode at 3/32" diameter at about 90 amps using reverse polarity. Just my opinion based on what has worked for me over the years. Pre and post heat and stress relieving would also be beneficial.
Good Luck,
Jeff
Good Luck,
Jeff
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Re: What filler rod to use?
i would consider both the silica bronze with tig or the stainless rods. either would call for preheat and a slow cooling. like ashes in the woodstove or the preheated floor dry in a hot oven. unless you want to buy your bride a new over consider snaging a used unit from behind western auto. use it and return it when done.
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Re: What filler rod to use?
Have you done this project yet? Just wondering the outcome.
Re: What filler rod to use?
I have to run to Norco to see if they have any Silicon bronze rod. This is a small town, I wonder what the chances are they will have it?
HJ
HJ
Re: What filler rod to use?
If they don't try Airgas, the store in Caldwell, Id. had it.
Jack.
Jack.
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Re: What filler rod to use?
I've TIG welded cast iron with nickel 59 and 99, as well silicon bronze many times. These fillers always leave a noticeable color difference from the original iron, as they don't rust (really only important on restorations). For the last several repairs, I have been using old piston rings from small block Chevy engines. The welded areas rust orange and finish nicely. My favorite part is that old rings don't cost $50.00/lb...