welding and cast iron

[jem]

I have an old and cheap vice, which I decided to use as a vice on a stick a la Roger, I presume that it was cast iron.

So yesterday I ran a bead of mig welding wire on a bit of it to see how it would go, and that seemed to take very well.

Today I made the vice stick up. I was using stick welding for another job, so I tried to weld up the vice to the stick with stick welding, and this did not work at all. then I used mig and it seems to have worked perfectly. I do know that cast iron is considered a problem to weld. so was surprised when mig welding seems to work so well.

I would be most grateful for any comment on this and especially from welders.

best wishes

Jem

[Jo]

You need a special type of welding rod for Cast Iron. Once you have one, wind the current up so it is a good hot weld and it should work.

Jo

[pault]

It could be the mig weld is just sitting on top of the iron, so it looks better than it is. Also if it is a good weld it can be quite brittle (locally chilled) so might not do well with shocks.

[goldstar31]

I'd be interested in learning what actually resulted in 'a bloody good clout' with a decent hammer.

The funny thing is my son's discussions this morning on gluing Lotus chassis being stronger than welding- and crashes.

Apologies but my mind wandered from 'Hot short' in cast iron

Regards

Norman

[ettingtonliam]

Mmm. My limited knowledge of having cast iron repairs done is that the item needs to be heated to nearly red before welding, using, as has been said, special rods for cast iron , and then covering the job with insulating blankets and allowing to cool very slowly.
Like Norman, I'd be interested to know the result of a hammer test on the weld Jem has done on his vice.

Richard

[jem]

Thank you very much for your replies, very interesting. I am not going to clout the vice on a stick, but I will do another mig weld on the bit I sawed off, and give that a clout. I know and agree that cast iron normally needs special rods, and is difficult at the best of times, but we will see, the weld certainly looks very good!!!

Jem

[ettingtonliam]

Yes. the results would be interesting to hear.

[jem]

I stick welded a bit of steel to the cast iron scrap that I had already put a bead of mig on, and that seemed to be quite good, but in a day or two, I will be doing more mig welding so should be able to do a proper job. But it does seem to me that you can get away with mig welding cast iron, as long as you are not working on space rockets!!

best wishes

Jem

[jackrae]

Could it be that the CO2 shielding gas used in MIG welding has a material effect on results.

[jem]

I did another check today, welding a long bar to the cast iron, using Mig, when I bent the bar, the weld gave way on the cast iron interface! So my conclusion is that yes you can mig weld cast iron to steel, but it is quite a week weld, so for my vice on a stick, it will do providing I dont be to rough with the vice!!

Yes thanks Jackrae I think that the shielding gas does make a difference, as stick welding was quite impossible.

I wonder if tig welding would do any better??

best wishes

Jem

[goldstar31]

Shouldn't it be possible with bronze wire and Argon?

Norman

[jackrae]

You might want to have a look at this guys example on tig 'welding' cast iron www.youtube.com/watch?v=xQN_yz-4Hhg
He does loads of free videos on various welding techniques with a new one at least every month

[jem]

I haven't got tig, so it was just a thought, but thanks for your inputs. I watch all his videos Jackrae, and find them very interesting, but he does use very expensive equipment, and has all the materials, which I have not got, still very interesting.

best wishes

Jem