hi ,, id like to hear how you use copper electrical wire ,, im always up for something new to try , many thanks.
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pressbrake1
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nickel prevents a build up of a hard crystalline structure, can’t remember the chemical name. It’s not the nickel itself being more malleable.
On lower carbon semi steel cast irons low hyd rods can work ok
Brazing can be good
Nickel rods really good
Stainless really depends on the iron for success
Heated to 800c iron filler rod and slow cool the best.
All the above is seriously dependent on the grade and quality of the cast iron
On lower carbon semi steel cast irons low hyd rods can work ok
Brazing can be good
Nickel rods really good
Stainless really depends on the iron for success
Heated to 800c iron filler rod and slow cool the best.
All the above is seriously dependent on the grade and quality of the cast iron
pressbrake1
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I forgot about copper. Luckily for me I rarely get involved anymore!
pressbrake1
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A blacksmith welded my fathers wood plane that was dropped and put back in his toolbox, the perp staying anonymous
That was 75 years ago and I’m using it now
Dcal
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Strip a bit of twin and earth and give it a go with tig.
Works well, even if it is a doesn't flow as well as proper tig brazing rods.
i shall indeed ,,, thats a new one on me , never imagined it would flow at all... many thanks
Paul.
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You have to work it a bit but its quite useable, this is not cast but the technique is much the same, these joints were tigged with a piece of stripped out 2.5mm cable, everything needs to be clean, including the wire, you can see a bit of muck in the end of the lap joint, I chased that all the way along the joint before it got the better of me.
God mode restorations
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I take it ya referring to this
Brad93
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The nickel works because it has a lower coefficient of thermal expansion, much like cast iron.
nickel promotes an austenitic formation rather than a very hard martensitic phase like you’d get using a steel filler. I presume this is what @pressbrake was talking about.
While I’m sure stainless filler does work from time to time, you put chromium in with carbon and you can start getting very very hard alloys/carbides.
I don’t know the compounds formed but the long and short is either braze, use nickel or use some of the ¼” square cast iron rods with acetylene, and the part at about 600 degrees.
nickel promotes an austenitic formation rather than a very hard martensitic phase like you’d get using a steel filler. I presume this is what @pressbrake was talking about.
While I’m sure stainless filler does work from time to time, you put chromium in with carbon and you can start getting very very hard alloys/carbides.
I don’t know the compounds formed but the long and short is either braze, use nickel or use some of the ¼” square cast iron rods with acetylene, and the part at about 600 degrees.
zeppelin builder
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for slow,cooling preheated portland cement powder is best
The high carbon in the cast iron (which makes it brittle) does not transfer to Nickel....so the Nickel stays soft and malleable
Even in the Nickel / Iron alloy there is enough Nickel to prevent it becoming brittle....but it will be harder than the pure Nickel
Even in the Nickel / Iron alloy there is enough Nickel to prevent it becoming brittle....but it will be harder than the pure Nickel
Old Dog
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Not been on the forum for a while, but the first thread I read is cast iron, very informative. My 1/2 pence worth, I've welded exhaust manifolds before with mig(only thing at hand), the German ones seem to weld OK but they seem to be good cast, A couple of weeks ago I had to weld a cast housing, so I bought 6 rods and welded it with them. I was well impressed, some of the best welding I have done, nothing to do with my skill as I think the rods were good rods and the cast was made in 1956 with a good finish and good grain, so like a lot of you have said the material has a lot to do with the end result.
Hopefuldave
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Hmmm, Would Invar work as a filler then? it's 36% nickel, the rest iron, I have quite a lot of it... Turns beautifully
Dave H. (the other one)
yepHmmm, Would Invar work as a filler then? it's 36% nickel, the rest iron, I have quite a lot of it... Turns beautifully
Dave H. (the other one)
Hopefuldave
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The most common wire for welding cast iron is 40% Nickel, its a bit cheaper. Some of the big users (who buy hundreds of tonnes a year) make Street Furniture and Grates and Manhole Covers......if they need welding they use the 40% alloy....its actually a better colour match
Hopefuldave
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That's Useful Knowledge, thanks - the Invar36 is VERY ductile, turning it the swarf comes off in thick shiny dreadlocks, e.g. 5mm wide / 1mm thick (it takes heavy cuts, but its using all the spindle HP!), if I don't interupt the cut they can get to 6 feet long! It also has the lowest coefficient of thermal expansion of any ferrous alloys, 1.2 ppm /C Vs 15 ppm for steels, about 11 ppm for cast iron so I *hope* that it will be a good filler, perhaps with some peening?
Dave H. (the other one)
Dont know what Im thinking...its the other way round 60% Nickel 40% Iron is the common one....but Invar should still work....sorry.....it will probably lose some of its ductility as it picks up carbon from the cast iron but should still be soft enough to give a crack free weld.
Hopefuldave
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Ah, right - I might buy some pure nickel rods then! I'll have a go on something that isn't critical with the Invar and see how it goes, I can grab a manifold or somehting at the scrappy and break it...
Dave H. (the other one)
