Pitlamp

Well-known member

• May 24, 2018

• #1

Is it possible to weld cast iron? (I seem to remember having heard it's difficult.)

If so, what's the best method - does standard frazzling tackle (electric arc) work or does it need something more sophisticated?

If anyone can advise - thanks!

 

Les W

Active member

• May 24, 2018

• #2

I know you can arc weld cast iron (I've done it) but I believe you need special rods (or rather rods with a special flux coating).
I don't know if you can weld it with other methods.

 

Robert Scott

Member

• May 24, 2018

• #3

Pitlamp said:

Is it possible to weld cast iron? (I seem to remember having heard it's difficult.)

If so, what's the best method - does standard frazzling tackle (electric arc) work or does it need something more sophisticated?

If anyone can advise - thanks!

Click to expand...

Hello John
PM sent about mutual friend not on this forum.
Regards
Robert

 

O

owd git

Active member

• May 24, 2018

• #4

have had cast iron  'stick ' welded with 'high carbon' rods. how big a job have you in mind? o. g. 

 

Pitlamp

Well-known member

• May 24, 2018

• #5

Many thanks for the information above - and to the three people who have sent a PM separately.

Just for completeness - as O.G. asked - it's a flange about 6 mm thick and maybe 20 mm wide (so quite a small job).

Cheers all.

 

T

tamarmole

Active member

• May 24, 2018

• #6

Yes you can.

They key is to get the work piece evenly heated before you start welding.  If you don't you can get differential expansion when you start welding and the work piece may fracture.

Might be worth talking to Baz.

 

Mark Wright

Active member

• May 24, 2018

• #7

Pitlamp said:

Is it possible to weld cast iron? (I seem to remember having heard it's difficult.)

If so, what's the best method - does standard frazzling tackle (electric arc) work or does it need something more sophisticated?

If anyone can advise - thanks!

Click to expand...

Tim Nixon used to work for Dorothea Architectural Iron Works in Buxton many years ago. He used to specialise in welding cast iron. He even built a cast iron staircase in Stings house.

I'll PM his email if you don't have it.

Mark

 

Pitlamp

Well-known member

• May 24, 2018

• #8

Thanks all.

Actually, I've just remembered that there's also a certain person in the Orpheus who would probably be able to advise.

I reckon between your various messages and posts here I should be able to get the information I'm after now. (I remember now that I've heard that thing about even heating before.)

Yet another example of how useful this forum can be.

 

NewStuff

New member

• May 25, 2018

• #9

If you use an arc (stick) welder with nickel rods and, arguably most importantly, preheat and a slow cooldown in hot sand (a BBQ comes in handy for DIY'ing it), it's usually possible to do it and get good, lasting results, but it's entirely dependant on the cast iron needing repair. Some (Usually very old) cast/pig iron is simply not weldable.

 

Pitlamp

Well-known member

• May 25, 2018

• #10

Thanks for the advice. 

 

traff

Member

• May 25, 2018

• #11

Brazing maybe easier depending on your requirements.

 

AR

Well-known member

• May 25, 2018

• #12

I welded some cast iron when I was at blacksmithing college, and from recollection (it was a long time ago!) I did it pretty much as Newstuff described - preheated on one of the smithing hearths, used high-nickel rods , and let it cool down nice and steady at the edge of the hearth - the critical thing is to avoid thermal stress on the metal so it doesn't crack. It is a bit of a faff so as Traff suggests, if a weld isn't necessary then brazing might be the best way to go.