[johndextr]

I have seen a video where some guys were welding cast iron using stick welding, there is no topic about that in the forum and I would like to know more information about it where can I get the electrodes since in welmongerstore.com isnt something like even on the videos that this master makes for us on youtube (not yet I hope) and those that I have found are expensive, so I´d appreciate some more information

[weldin mike 27]

cast iron can be stick welded a couple of different ways.

One is 7018 rods and preheat. The resulting weld will be hard and not drillable...ect.

Nickel Iron rods, pre heat and peen and slow cool. Do 1 inch long runs and peen the weld with a chipping hammer to allow the weld to stretch as the material contracts. slow cool in sand.

99% nickel rods and no pre heat but you have to let it cool down to hand touch temp before proceeding (actually called touch welding) inch long runs and peening as before. The goal in the short runs is to not dilute the weld metal with the cast iron basemetal more than absolute necessary.

If you have a thick piece of c/i you can "butter" the edges of the weld zone with the nickel rods. This means pad welding over the top and then welding up with another, cheaper rod, like 7018.

[weldin mike 27]

http://www.twi-global.com/technical-kno ... irons-025/

[MinnesotaDave]

Weldin_Mike: A question if I may, why use a chipping hammer for peening?
My experience, which isn't nearly as much as many others, has been to use rounded tools for peening.
Like the round end of a ball peen hammer, or a needle scaler with rounded needles.

For the OP, the two commonly available rods near me are nickel 99 and nickel 55, the Ferroweld rods listed below I have not seen in my local store.

Lincoln:
Choosing electrodes for welding cast iron typically comes down to three things: cost, machine-ability, and whether the weld is single or multiple pass.

Tech-Rod 99 (AWS class ENi-CI) is a nominally 99% Nickel electrode. Nickel is expensive, and so, therefore, is this premium electrode. The electrode will deposit welds that are machine-able, an important consideration when the casting is to be machined after welding. Repairs made with Tech-Rod 99 are often single pass welds with high admixture. Even with high admixture, the weld deposit will remain machine-able. It works best on castings with low or medium phosphorous contents.

Tech-Rod 55 (AWS class ENiFe-CI) is a nominally 55% Nickel electrode. The lower Nickel content makes this electrode more economical than Tech-Rod 99. Weld deposits are usually machine-able, but under conditions of high admixture, the welds can become hard and difficult to machine. It is often used for repairing castings with heavy or thick sections. As compared to Tech-Rod 99, welds made with 55 Ni are stronger and more ductile, and more tolerant of phosphorous in the casting. It also has a lower coefficient of expansion than 99Ni, resulting in fewer fusion line cracks.

Ferroweld (AWS class ESt) is a lower cost, steel electrode. The weld deposits are hard, and are not machine-able, but can be finished by grinding. This is the lowest cost electrode for welding cast iron, and the electrode has a very user-friendly arc. It can tolerate welding on castings that cannot be completely cleaned before welding. Ferroweld deposits will rust, just like cast iron. This may be important when repairing cast iron parts such as exhaust manifolds on antique cars.

[weldin mike 27]

Why not? It good for banging and also getting into a corner or groove. Id use the rounded spiky end of a chipping hammer, for likeness to the needle gun, and availability. However I, as usual, am just regurgitating info i heard other places. (I've peened welds,but that was on low alloy steel, with a needle gun.)

[Olivero]

IF you can, I would recommend TIG welding it.

The cast iron rods are expensive As all hell and I have considered getting them in case I couldn't fix it by TIG but I always manage to get it done with the TIG.

Regardless of welding procedure, its gotta be allowed to cool really slowly, no dousing in water, dunking in buckets, throwing it in the pond, none of that. I actually use stainless rod when I do cast, I believe its slightly more elastic than steel so the cooling process where the metal contracts doesen't seem to crack it, I like to think that's why.

You could also try stainless stick electrodes, never done that before on cast but it might work.

[MinnesotaDave]

You could also try tig brazing with aluminum-bronze.

I gave it a whirl a while back since Jody was kind enough to show how to do it on his website.

If it helps, here is the thread I posted: http://forum.weldingtipsandtricks.com/v ... =9&t=11339

[Olivero]

TIG Brazing? what on earth is that? using a brazing filler/rod but using TIG for heat instead of a torch?

[Farmwelding]

TIG Brazing? what on earth is that? using a brazing filler/rod but using TIG for heat instead of a torch?

https://www.youtube.com/watch?v=wf-Cq5eQmt0

https://www.youtube.com/watch?v=AyY0PYed3yc

https://www.youtube.com/watch?v=xQN_yz-4Hhg&t=13s

That's a start to vrything about tig brazing and brazing cast iron.

[MinnesotaDave]

TIG Brazing? what on earth is that? using a brazing filler/rod but using TIG for heat instead of a torch?

For the most part, yes. Except the filler rod isn't the flux coated oxy/acetylene rods (in my case anyway).

In the post I linked I used aluminum bronze rod.

Silicon bronze is also very common.

It was the first time I had tried TIG brazing and it went very well.
Using a foot control made it much easier than oxy/fuel in my opinion.

[Olivero]

I've TIG welded using silica bronze before and keep some on the shelf, never heard of TIG brazing though.

I do refrigeration work as well so I have the 15% silver rods, not sure about flux coated ones.

[olek]

If you have a thick piece of c/i you can "butter" the edges of the weld zone with the nickel rods. This means pad welding over the top and then welding up with another, cheaper rod, like 7018.

Hello that is a good short resume . I did read preferably NiFe rods , may be for thermal expansion or suppleness characteristics.

NiFe used for less ductile weld.

I had to learn to weld enough to weld an iron frame with a partial crack ( drilled to release stress and stop it) . Crack from undue stress so I have some chances of success as this will be released.

I was told that in that case, if the crack did close jointive , just take an cast iron repair electrode 1/8 make a soft pre heat 100 celsius , and directly secure the edges of the crack after a good securing with dots of weld ( the name escapes me sorry)
Small 1/2 inches pinned (not so strong ) with a rounded tool. As soon you can put a finger go along ..as you said.

A friend did that a lot when repairing electtical machines or big ones on an atomic plant. The crack must be closed. And the heated zone reduced to the max.

As the weld go thru the iron so easily one have some penetration without opening the crack. In my case 3/8 thickness and I wanted to go thru with a X opening. No open root to limit deformation . One side , ( not long 1.5 ") open other side then test for cracks then other side then last bead (s)

[olek]

For the OP, the two commonly available rods near me are nickel 99 and nickel 55, the Ferroweld rods listed below I have not seen in my local store[/i]

Dave chances are that your nickel 55 are bimetal NiFe.

Older welders did talk of iron electrodes but this did not work well.

Some iron will crack very easily when the weld cools peening limits that (with rounded tool), but root pass =no peening, say some instructions from elecrode makers.

Thin 2.5mm electrode for root. Minimal heat . If I had a too round bead I immediately cut it in the middle with a grinder , ( after peening)

We are supposed to see the peening traces so a too light hammer does not do ...but extra strong peening ...may be dangerous on thin grey iron. Less on spherical graphite iron wich is more robust.
Ductile iron can be peened with a pneumatic needle tool rounded I think.
Best

[bowleggid]

One of the most important things to consider when welding cast iron is weld prep. How you prepare the surface to be welded will have a great impact on weldability. Rule #1: Never touch cast iron with an abrasive. Most people break this rule, using a grinder to cut a nice groove in a cracked piece of cast iron (assuming a repair here.) All that does is smear graphite all over the surface to be welded, & the resulting weld looks like swiss cheese. Those same guys grind out the weld & do it again, & they get baby swiss cheese, & they do it again, & smaller holes, but still porous!
Simply use either a carbide burr (in a die grinder) to cut the cracked casting instead of abrading it. Or better yet -- if you know how to use a cutting electrode (gouge rod) -- gouge the crack to be welded. Now, don't use a carbon arc to gouge it, use a gouging electrode. That way you won't introduce more carbon to the casting, & you'll preheat it in the process.
Speaking of preheat, 400 deg. F is a good preheat for cast iron. Peening & annealing are also good practices, as mentioned in other responses.
Filler rod: Nickel-based alloy made for cast iron, as mentioned in other responses, or go here to see some excellent filler rods for cast iron (warning they're not cheap.) http://weldit.com/product_category/stic ... cast-iron/
What alloy (A/AAA or B/BBB) you need is based on whether you need the weld to be super strong, or super machinable. (the B's are the more machinable, the A's are stronger.)

[olek]

One of the most important things to consider when welding cast iron is weld prep. How you prepare the surface to be welded will have a great impact on weldability. Rule #1: Never touch cast iron with an abrasive. Most people break this rule, using a grinder to cut a nice groove in a cracked piece of cast iron (assuming a repair here.) All that does is smear graphite all over the surface to be welded, & the resulting weld looks like swiss cheese. Those same guys grind out the weld & do it again, & they get baby swiss cheese, & they do it again, & smaller holes, but still porous!
Simply use either a carbide burr (in a die grinder) to cut the cracked casting instead of abrading it. Or better yet -- if you know how to use a cutting electrode (gouge rod) -- gouge the crack to be welded. Now, don't use a carbon arc to gouge it, use a gouging electrode. That way you won't introduce more carbon to the casting, & you'll preheat it in the process.
Speaking of preheat, 400 deg. F is a good preheat for cast iron. Peening & annealing are also good practices, as mentioned in other responses.
Filler rod: Nickel-based alloy made for cast iron, as mentioned in other responses, or go here to see some excellent filler rods for cast iron (warning they're not cheap.) http://weldit.com/product_category/stic ... cast-iron/
What alloy (A/AAA or B/BBB) you need is based on whether you need the weld to be super strong, or super machinable. (the B's are the more machinable, the A's are stronger.)

I agree .yesterday I did make a few small welds on an iron balcony. a crack and securing the rake rail , I had to clean old rust and old paint down to bare metal plus a small v groove with carbide tool, any trace of rust and the weld was rejected.
pre heat 160 F just to avoid thermal shock (control with a a laser thermometer, but special pens are better).

the cooling is the difficult part, as keeping weld beads small. if you get too confident and make a long weld, snap
cooling is very fast with the "cold regime', Esab even tell us to fasten it by blowing air around the weld, not on it.'.

with cracks secured by holes ,leaving them open is a good (security) option if possible.it is anyway very difficult to fill those holes withè

Wear gloves and protective face shield with carbide burrs they make projectiles that enter too deep in the flesh to be extracted easily sometime. And then, trouble, it get infectious soon, you may be sure your tetanus vaccine is up to date, and often open the flesh to allow the metal to be pushed out. An usb microscope or strong x30 60 magnifier with less help for that.
Don't ask me ..
Best regards

[olek]

Here is a link with iron electrodes and their use.

I did receive answers from the manager of that brand .

http://www.magmaweld.com/cast_iron.html

a training video from Castolin 224

All the electrodes for iron I have did look like those ones see below, English version

Used DCEN for "cold regime" from 60 to 80° celsius (140 -212 F )

DCEP if the object is cooked 500 600°celsius, (932 °F to 1112 F) then allowed to cool slowly (24 hours ideal)

https://youtu.be/FawQHeOoU6E