Weldability of Cast Steel

[Dan Crabtree]

Hey everyone. I recently got an order for a fence that is about 62' long. The folks that ordered it want a finial welded on the top of every other stake. The thing is they do not want me to forge the finials, rather order them in (bummer, huh?) Well I was looking the Kings metal supply website and they have cast steel finials which look nice and I almost refuse to use any forged finials... i dont know just something about buying a forged finial irks me. I was wondering does cast steel weld just the same as regular steel, It is going to be welded to a 1/2 round bar. Thanks for any advice.

[GrandLordKhorne]

It really depends on the specific alloy of cast steel (There are about 150 different cast steels in the UNS book alone). But as a general rule of thumb most cast steel is a pain in the rear to weld and tends to get brittle. Having said that, proper preparation and the right filler metal and it can be welded just fine in most cases. My suggestion would be to buy extra and make a test/practice weld or two on it to see how it dose and adjust your weld procedure accordingly. Or just lie and make your own, or tell the customer where to stick it (Personally I like telling the customer where to stick it, I hate using other peoples components unless I can’t make them my self).

That is just my $.02

[Thomas Dean]

Friend of mine uses these all the time and welds them to every picket, some gate are 20' wide. Anywho....in the shop he just MIG welds them using .035 E70-S6 wire, when welding them in the field, (out of the shop) he just uses E7018

[Mills]

Same here, only I carry the MIG with me

Thomas not to hijack the thread but what of Cast Iron Finials? I have wondered if it would be worth the cost to use a SS wire to get them to hold better. I have spotty results using the E70-S6 wire.

[Ice Czar]

On occassion we use those cast pieces from King Architectural but not the Finials. What we typically do is drill them and plug weld with a MIG to the bar, then regrind.

[Thomas Dean]

Hey Larry! good to hear from ya. He uses the same, ya gotta remember this is a non-critical weld, it just hold the finial in place and actually a solid weld is not needed. If you run into having porosity in the weld, Mike, my friend that does this for a living, will on occasion fill the holes with primer paint. He will use the paint on the side of a bucket just as it is starting to dry, it is then like a thin putty with no need of sanding. Obviously you don't do this on and welds that need to have any strength. There is also an alloy dual sheild wire that he uses on the big cast iron elements such as the grape leaves with grape cllusters and vines in a secton. That stuff is expensive but will weld the cast iron part to the steel tube very well. You can use regular dual shield wire but it ususally cracks the first weld and you have to go back and reweld. The first weld actually is 'buttering' the cast part to allow you to weld the 2 pieces together. Sorry for the LONG post and it's really not as hard as it sounds.

[Hillbillysmith]

Cast STEEL can most definatly be welded to mild steel. Just use a little bit of preheat (about 250-300 degrees F) and weld. Cast IRON on the other hand is a whole nother animal..... :D

[Thomas Dean]

Not to steal this thread....My LG 50#er needs some welding around the dovetail and I asked Sid how they made these reapairs. He told me to just preheat to about 300-350F and can be built up with 70S MIG. That's how he does it.

[arftist]

To weld cast iron finials to th end of pickets, nickel rods work.

[aametalmaster]

I don't think the finials are cast steel at least the ones i bought from them, they are cast iron and i welded them with my mig also, not proper but it worked...Bob

[Dodge]

Many of the attachments on street lighting poles is cast steel. We welded these to the mild steel poles and except for occasional casting flaws, there was no difference between welding these and welding mild plate to the poles.

[irnsrgn]

most any rod will stick to cast, what makes the weld fail is the free carbon that forms (concentrates between the weld and the cast, this is a problem with nickel welding cast too. If you want the finials to stay stuck even during rough treatment, wire brush or polish grind the finial end and the bottom of the cast finial and soft solder them on with acid core solder.

If they are not a really good fit when you tack weld them on, someone grabbing the finial will break the weld at the free carbon zone.