Need to weld some cast iron. Got some questions.

[ARAMP1]

I need to weld a water manifold that is cast iron. Should I use the TIG or ARC welder? What type of rod should I use?

Also, it's small enough where I could fire up the grill and warm it up so it could be welded warm and cooled down slowly, but it's not a structural part and it won't see very high temps (I'm thinking 200-300 degrees F). Do I need to do that or could I just weld it out in the open in the garage?

 

[Stomis]

Ok from what I've read and I'm sure someone will correct me if I'm wrong but 100% proper procedure is.

Grind the rough finish from the metal.

Heat area in the temperature range of a typical hardware store mapp torch

Stick weld using a nickle rod

Bury the weld in sand so it cools as slow as possible.

 

[Thunder]

Pretty much as said above. Dont heat above 1400 degrees. Use the lowest current possible. If you have a long area to weld it is best to do small segments of around 1" at a time. Doing long continious welds on cast causes stress and may overheat the metal causing cracks. If it is a water manifold you may get some small cracks around the weld. I usually seal the weld and area around the weld with JB weld afterwards just to make sure there are no small leaks.

 

[livid4dirt]

Cool very slowly! A good way to make sure that happens: Cover your casting in Briquettes torch them off when the Briquettes become white or ready for cooking pull out your casting weld it up, then back in the Barbie cover your casting in the hot Briquettes until they cool completely down. Done this quite a few times and it works great.

 

[Stomis]

Cool very slowly! A good way to make sure that happens: Cover your casting in Briquettes torch them off when the Briquettes become white or ready for cooking pull out your casting weld it up, then back in the Barbie cover your casting in the hot Briquettes until they cool completely down. Done this quite a few times and it works great.

Theres a good idea

 

[Merv]

From what i've gathered. The type of welder used isn't really important. The user being competent is of course. Just cool it slowly like stated.

I have a question to add too.

Anybody ever heard of using Stainless wire for welding to cast?

 

[ARAMP1]

The user being competent is of course.

Probably the biggest challenge.

 

[tRustyK5]

I've had good success peening the weld as I go which helps by reducing the stress in the part. Ni-Rod is gonna be your best bet, and X eleventy on the super slow cooling.

Rene

 

[Stomis]

From what i've gathered. The type of welder used isn't really important. The user being competent is of course. Just cool it slowly like stated.

I have a question to add too.

Anybody ever heard of using Stainless wire for welding to cast?

Yeah the issue there being that I dont think they make nickel spools for mig...

 

[DEMON44]

I had a welder at work weld up one of my exhaust manifolds from my old cummins. as stated above nickle rods. take a carbide bit diegrinder to wallow it out. and cool slow. it still got surrounding cracks in it but didn't leak soot. Realizing this sees 1700+ degrees plus on occasion its not bad. but sealing coolant might be tougher.

 

[blazinzuk]

Yeah the issue there being that I dont think they make nickel spools for mig...

They do but they are spendy, heres a link http://www.htpweld.com/products/welding_wire/index.htm#Specialty Wires

 

[Stomis]

They do but they are spendy, heres a link http://www.htpweld.com/products/welding_wire/index.htm#Specialty Wires

Damn never seen that before.

 

[British Slave]

Do the old fashioned thing and braze it. Low pressure, low heat perfect for brazing. Grind a v groove down to smooth metal and get after it.