xtremek
Well-known member
So I need to weld some cast iron. I have a mig and oxy-actylene torches. If I put 308L in my mig and run Argon-CO2, will the welds hold? Or would bronze rod and the oxy-act work better?
Welding Cast Iron
- Thread starter xtremek
- Start date
BillK
Well-known member
Not enough details. What exactly are you welding ?
Depending on the broken part;
Grind a bevel on each piece, clamp in place. Build a charcoal fire in your "Happy Cooker". Put part on coals, let heat up to maximum heat, weld, put lid on and let fire die out and cool off.
The concentrated heat is your enemy. This method heats and cools the entire part gradually.
Use nickel rod.
Regards, ju539
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Grind a bevel on each piece, clamp in place. Build a charcoal fire in your "Happy Cooker". Put part on coals, let heat up to maximum heat, weld, put lid on and let fire die out and cool off.
The concentrated heat is your enemy. This method heats and cools the entire part gradually.
Use nickel rod.
Regards, ju539
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Punchwood
Well-known member
308L is stainless. Poor choice. Google is your friend.
Tim The Tool Man
Well-known member
I have successfully welded cast iron on a couple occasions with my cheap horrible freight welder. One was a part to a band saw bearing guide and another was a cracked head from my compressor. Both parts have held up for several years now. I Googled how to weld cast iron and used whatever rods they recommended. I ground grooves where I wanted the weld to lay. I cranked my wood burner up as high as I could get it and heated the part up then I used my blow torch to heat it up further. I then made my welds and threw the parts back in the stove for the night.
Worked fine and I am definitely not a professional welder!
Worked fine and I am definitely not a professional welder!
Higgins
Well-known member
We've had to weld several antique fireplace surounds back together! They were sand castings, and we had to pay attention to not putting too much heat on the pieces.
We placed the large piece on a table covered in sand to absorb some of the heat, and also keep the piece warm, and slowly allow it to cool.
While welding, had another helper using OA torch to keep the piece and sand warm. This helped the metal from running additional stress cracks as it cools.
As for welding, one piece we used TIG, the other OA and we braised it! In both cases we tacked the pieces in place, and then went back and filled in!
If you get it too hot, and then it cools, you will hear a crack develop and it sounds like glass braking........ Not fun, as now you have to stitch it back together!! Secret is uniform heat, don't over do it, and have you assistant keep heat on the sand and slowly cool it down!
AL
We placed the large piece on a table covered in sand to absorb some of the heat, and also keep the piece warm, and slowly allow it to cool.
While welding, had another helper using OA torch to keep the piece and sand warm. This helped the metal from running additional stress cracks as it cools.
As for welding, one piece we used TIG, the other OA and we braised it! In both cases we tacked the pieces in place, and then went back and filled in!
If you get it too hot, and then it cools, you will hear a crack develop and it sounds like glass braking........ Not fun, as now you have to stitch it back together!! Secret is uniform heat, don't over do it, and have you assistant keep heat on the sand and slowly cool it down!
AL
Punchwood
Well-known member
Er70s2 is for mild steel, not cast iron. Welding cast iron successfully is an art unto itself. Going by your questions I would suggest you just take whatever it is that you have to the local weld shop and let them do it.
By the time you get a proper machine, electrodes, etc. you'll be further ahead letting someone who's properly equipped do the job.
By the time you get a proper machine, electrodes, etc. you'll be further ahead letting someone who's properly equipped do the job.
theoldwizard1
Well-known member
rsanter
Well-known member
I have done it several times with no failures. I have even welded heads with no failures.
I heat the part in the BBQ and get it nice and hot.
Open the top and put a torch on the area to be welded. You want to see some color in the metal to know it is up to temp.
Pull the torch away and use the MIG welder.
Put the torch back on the area welded for about 10 min.
Pull the torch and close the BBQ and let it sit there for half an hour to an hour running.
Turn off the BBQ and just leave the part till cool
Bob
I heat the part in the BBQ and get it nice and hot.
Open the top and put a torch on the area to be welded. You want to see some color in the metal to know it is up to temp.
Pull the torch away and use the MIG welder.
Put the torch back on the area welded for about 10 min.
Pull the torch and close the BBQ and let it sit there for half an hour to an hour running.
Turn off the BBQ and just leave the part till cool
Bob
309L is the stainless rod if you tig not really sure about mig. or those ni rods expensive.
I had some success in preheat the parts first then just use regular flux core mig over pieces. Those are none structure items so far (small part on the jaw of a vice, and feet of a band saw stand) just keep heat over a wide areas of the parts with a propane torch during and after finish mig and bury over dry sand to allow it to cool slowly, Then some times some just crack on other pieces I tried. maintain heat over a wide area is important, if any area that cools too fast than others it might create stress crack is whats explained to me over other forums.
oops:
didn't realize
Higgins and rsanter already said it.
I had some success in preheat the parts first then just use regular flux core mig over pieces. Those are none structure items so far (small part on the jaw of a vice, and feet of a band saw stand) just keep heat over a wide areas of the parts with a propane torch during and after finish mig and bury over dry sand to allow it to cool slowly, Then some times some just crack on other pieces I tried. maintain heat over a wide area is important, if any area that cools too fast than others it might create stress crack is whats explained to me over other forums.
oops:
didn't realize
Higgins and rsanter already said it.
Last edited: