Cast Iron

[Buddy]

Good thread!

Man!

Just what the doctor ordered. I was in my doctor's office this past week, and he asked if I new anything about cast iron welding. I told him only that it could be quite tricky. This thread confirms it. He has checked around our area, with little luck. The piece is a cast lamp post from the French Quarter of New Oleans. He bid, and won, the posts. One is broken. I talked with an area welding inpector/instructor, and he echoed the "trickyness".

My next task in my welding efforts--to learn to repair cast iron (as many proceedures as work). What an interesting endeavor. Good luck Meach. Let us know the course you choose, and the results you get!!

[moosedog]

Forgive my ignorance, but what does the peening do?

In easy terms as the cast iron transfers heat very well, it also expands and contracts like all metals. If you just weld a bead on cast the heat being transferred away from the weld pulls itself away from the weld cracking next too it. Preheat swells up the metal but the weld is still much hotter and the peening pushes the weld material towards the base material and hopefully keeps it from cracking. The critical time is when there is a big difference between the welds heat and the base metal heat.

[calweld]

Another way to fix odd-shaped items if you don't want to preheat or it's not practical to preheat the entire thing and you have no time pressure is to do a little at a time. You can almost always put a 1/2" of nickel weld on a casting without cracking, especially if you peen afterwards. It might take a week, put a little weld on in the morning and a little weld in the evening, it takes a lot of patience and discipline, I've done this before and had good results. Not sure if this would work as well with brazing, you need to get a certain amount of heat on to get started and it would tend to crack what you already did, I think brazing would be better to do the whole thing at once.

[Cronatron Rep]

no need for all this preheating/peaning/cool down stuff

Cast Iron repair is alot easier than the way of "back in the day"

Cronatron, Certanium, Freedom Alloys, Eutectic, Nassua Rockmount all have products that you just weld (stitch) it up and you're done. Most are in the 75,000 to 85,000 psi tensile strength with a elongation of 25 to 30 %. These rods will burn right thru rust,paint, oil,grease and will also weld mild steel to the cast iron.

I think people get caught up in talking (some bragging) how they can repair cast the old way, as we all know welders are very proud of their skills and some (not all) like to make things look harder than they may actually be.

[tigman]

Cronatron Rep that is so true about making it seem harder than it is. We do quite abit of repair and build up on cast iron and use eutectic 2240. When you have a 1000lb casting you can't heat it up so you do alot of cold cast welding.

I think everyone should find a piece of scrap, grab some rods and actually give it a try to really get the feel for it. I have to admit its my second favorite material to weld right behind aluminum.

[billie-1]

i am no expert at it but i have welded some cast stuff .....most of it cold....just weld 1/2 inch or so and don't go back till you can hold your hand on it..repeat and no problems

[jbmprods]

i am no expert at it but i have welded some cast stuff .....most of it cold....just weld 1/2 inch or so and don't go back till you can hold your hand on it..repeat and no problems

i gave up testing it with my hand. most of the time it didn't take me long to check it out...oh ****tttt. an IR gun is much gentler to the touch

[calweld]

Cast Iron repair is alot easier than the way of "back in the day"

Cronatron, Certanium, Freedom Alloys, Eutectic, Nassua Rockmount all have products that you just weld (stitch) it up and you're done. Most are in the 75,000 to 85,000 psi tensile strength with a elongation of 25 to 30 %. These rods will burn right thru rust,paint, oil,grease and will also weld mild steel to the cast iron.

I think people get caught up in talking (some bragging) how they can repair cast the old way, as we all know welders are very proud of their skills and some (not all) like to make things look harder than they may actually be.

What you say is correct, many of the new alloys reduce or eliminate the need for the special precautions on many castings. Where a person still gets problems, however, is on items that are odd-shaped and where thickness varies through the casting, especially if it is where the welding needs to be done. When you weld an area, the casting itself will still expand in that area, if there is nowhere for the expansion to go oftentimes you get new cracks not even close to the one you are welding. The specialty electrodes do help reduce the cracking associated with shrinkage, but not necessarily with the cracking associated with expansion.

That's why I suggested welding a little at a time. If you happen to have one of the specialty electrodes, you can probably skip the peening step.

[jbmprods]

That's why I suggested welding a little at a time. If you happen to have one of the specialty electrodes, you can probably skip the peening step.

anything you do might be the ticket to success. anything you don't do might be the ticket to failure. an ounce of prevention is worth a pound of cure.

[moosedog]

Cast Iron repair is alot easier than the way of "back in the day"

Cronatron, Certanium, Freedom Alloys, Eutectic, Nassua Rockmount all have products that you just weld (stitch) it up and you're done. Most are in the 75,000 to 85,000 psi tensile strength with a elongation of 25 to 30 %. These rods will burn right thru rust,paint, oil,grease and will also weld mild steel to the cast iron.
.

This is very good news! Cuz back in the day,,,, Well you you know! LOL!

[gabrams55]

Here is the cast iron product being used

https://youtu.be/0XBgqNvfsgs