TIG or MMA for cast iron

[GUI]

Hi all

I have a new job to make,and want to make it good,so i need advices .

I need to weld a turbo exhaust flang to a exhaust manifold ,is 2 pices of cast iron.

I have a AC/DC 200 weld so i can weld tig or MMA....dont now the best to use for this job.I have see many people weld cast iron whit MMA cast iron rod ,setting machin in 90/110A and pre hit the cast iron to 650/700cº,the weld must be by step´s and cold slowly .

I have make a search ,see some people using stailess stell for repair cast iron ....

cast iron is C+SI+MN+FE and stailess stell is CR+NI+MN+C a repair is not the weld that i´m going to make,so i need to now the best process ....

I also have TIG and some rod´s of 304ss and 308ss dont have nickel rod at the moment...

Any idea??


Best regards to all

 

[TechnicAl]

In my opinion the best results are achieved with stick rod specifically designed for the purpose. So a Nickel or a Nickel/Iron rod (dependent on the grade of CI). They have graphite coatings designed to run on low amps and will probably put less heat into the CI and as such minimise the shock.

 

[GUI]

Tanks for the advice

It have a diameter of 6/7mm each flang pre heating to 650º i think is to much .... i´ll try a low heat and see ....maybe 100º will be nice,is not a big peace ...


SS is out of question for this

 

[GUI]

Abaut sparks...cast steel and cast iron are diferent right??

 

[TechnicAl]

dont preheat...keep the runs short and peen the weld

 

[GUI]

I have see this topic

Is a garrett exhaust also.....

http://www.mig-welding.co.uk/forum/showthread.php?t=17762&page=3&highlight=garrett

312ss rod for mma is a option??dont now what to use for make a perfect job...dont want cracks



Tanks for the advices mr TechnicAl

 

[shenion]

you may look at cost for the filler/electodes.

I was able to get a 3-pack of nickel MMA rods cheap (marked as dissimilar metal rods.). A full box is a fortune. Same probably for TIG rods. Talk to your supplier to see what he has.

I have do small cast iron repairs using 308 stainless wire. Worked well. 312/316 is supposed to be better.

The cast iron arc rods worked well on my vice. Did short welds with no preheat/postheat. Just made sure it was cool enough to touch on each weld.

 

[Tigman]

I agree , dont pre or postheat , just take your time , try peening , does`nt hurt to do it and let it cool naturaly , have a look at the Arc Welding Section , you will see a pump I repaired with no preheat ! saved the day with that one , then the company broke the next pump had to do it again , clumsy Ba****** , Hehehehe !

 

[hotrodder]

I have see this topic

Is a garrett exhaust also.....

http://www.mig-welding.co.uk/forum/showthread.php?t=17762&page=3&highlight=garrett

312ss rod for mma is a option??dont now what to use for make a perfect job...dont want cracks



Tanks for the advices mr TechnicAl

The 312 suggestion in the thread you linked to was for cast steel as Veylum decided the parts were cast steel after spark testing.

 

[GUI]

So i need to now if is cast iron or cast steel

Spark test is must be

Cast iron - red/orange sparks
Cast steel -white sparks

I´m right??

Nickel for the 2 cast´s and if is cast steel i can use 312ss

 

[Tino]

So i need to now if is cast iron or cast steel

Spark test is must be

Cast iron - red/orange sparks
Cast steel -white sparks

I´m right??

Nickel for the 2 cast´s and if is cast steel i can use 312ss

After reading through the thred, I'd say yes. And good luck

 

[hotrodder]

Yeah, the type and volume of sparks differ too. here's a video... http://www.youtube.com/watch?v=5R1Y6_g0DU8 There was also a link posted with more detail on material identification including spark testing and chip testing in the other thread, here in case you missed it

 

[GUI]

The job is done,no crak at he moment,i use ni stick rod´s 3,25 ,very expensive 10 rod´s 43€

 

[mike os]

cheap if it does the job tho

 

[pedrobedro]

Drilling is a good test for cast iron as well, I helped next door repair his gate and when we drilled it the iron makes like a grey flake almost a coarse powder where steel make shiny threads and larger spirals if the drill is sharp. Handy if you don't have an angle grinder or the piece is too big to hoist to a bench grinder.

 

[shenion]

Yup, that is expensive

Mine was $5 for 3 rods. Actually picked them up at a local hardware store. Was stunned to see them there.

 

[TechnicAl]

Just a cautionary note

These "tests" being mentioned are fine if its grey iron or SG iron but there are lots and lots of other grades of cast iron some considerably harder than the SG / Grey.