MIG welding cast iron

[DavidR8]

Impressive stuff here!

 

[YotaBota]

Are you going to try it on the broken bracket?

BTW - is tomorrow night still the night for pickup?

 

[DavidR8]

Are you going to try it on the broken bracket?

BTW - is tomorrow night still the night for pickup?

Yes, I'm thinking about it MIG or TIG brazing it. I have silicon bronze TIG rods already so no cost to try it. There are two big pieces which complete the bearing holder and a couple of small bits that form the ridge that the bearing seats against.
Yup tomorrow is the night

 

[Proxule]

"doesn't have to look good to be strong " lol tell that to the inspector.
Make sure you clean the snot out of it if you plan to TIG braze it, I suppose the MIG is more forgiving in that aspect.

gluck!

 

[DavidR8]

"doesn't have to look good to be strong " lol tell that to the inspector.
Make sure you clean the snot out of it if you plan to TIG braze it, I suppose the MIG is more forgiving in that aspect.

gluck!

I might spring for a roll of SIB wire, could be handy to have.

 

[Bandit]

Big problem I had with mig welding cast iron cranks was porosity, never did find a real answer. Just lived with it and ground those areas out and welded again. Even tried a 1200 degree F. burnout held for about 6 hrs at the 1200 degrees and cooled overnite.
This was using Ni-Rod 55 wire, the boundry layer was a bear, tough and hard, the carbide bits suffered.
We had a couple of test cranks done with tig, but it was very slow and we didn't have tig gear, but had mig, so that was the way we went.
Grinding would be the way to go, but can leave behind unknowns that can complicate rewelding if needed.
Once brazed, may only be able to be brazed after. Brazing can propably be machined after if let to cool slowly.
It also been 30 years since, so maybe some different materials about now.

 

[Former Member]

I have MIG'd sone cast, eh...results. I have TIG some cast way better results.

I get a better feel for the puddle with TIG. My limited understanding is use SS filler and ideally for best results penning or heat control in cool down to avoid stress fractures. Brazing also works, but have yet to try it even though I have rods for it.

Again no expert here, so do your research.

 

[Proxule]

This was using Ni-Rod 55 wire, the boundry layer was a bear, tough and hard, the carbide bits suffered.

I have had the same experience, I now tend to lean towards nickel 99 and peening the area quickly.
With nickel 99 the weld easily yields during cooling / room temps. Especially with peening. I limit my length of weld to 2 inches or so if its a critical part, Otherwise I full temp that sucker with PRE heat and weld away.
Nickel 99 is highly machinable, but lacks the ductility of nickel 55.

Brazing has proven the least eventful in my experience.

 

[Proxule]

penning or heat control in cool down to avoid stress fractures. Brazing also works, but have yet to try it even though I have rods for it.

 

[DavidR8]

I’ve been watching Keith Rucker and a bunch of other folks MiG and TIG brazing cast to get a sense of what what’s involved.
All are using silicon bronze wire/rods.

I have a junk import cast iron drill press base that I might cut up to try my luck at TIG brazing it together.

 

[Dodgeboy426]

Nickel 99 is what I typically use either stick or tig. Always had good results. Just keep welds short and peen lots

 

[Dan Dubeau]

I have mig brazed with good success. Tig brazed also. Preheat is crucial with silbr mig braze though, once I got that right it went down like butter. Never hurt to have too many options. It's more designed for sheet metal fixing bodywork etc, to keep heat down and distortion to a minimum, so it's working against you on a cast repair.

I did pickup some cast iron stick rods, but haven't had a chance to use them yet. The few times I tried to mig weld cast it was a waste of time and energy.