Welding Cast Iron to Structural Steel
Welding Cast Iron to Structural Steel
(OP)
I was asked to look at a remodling project where the "Architect" called for a new steel beam supporting second floor wood joist to be jacked into place and sit atop existing cast iron columns. Literally SIT.
The round ornamental cast iron columns are approximately 14' tall. A steel plate is laid on top of the columns, then the new steel beams sit on the plate. The simple span beams meet over the plate, but there is no connection between beams, from the beams to the plate or the plate to the cast iron column. Every thing is sitting loose, with only the vertical dead weight of the upper floor "holding" the framing together.
My question is what welding rod can be used to weld the cast iron to the structural steel (A36 or equivalent)?
The round ornamental cast iron columns are approximately 14' tall. A steel plate is laid on top of the columns, then the new steel beams sit on the plate. The simple span beams meet over the plate, but there is no connection between beams, from the beams to the plate or the plate to the cast iron column. Every thing is sitting loose, with only the vertical dead weight of the upper floor "holding" the framing together.
My question is what welding rod can be used to weld the cast iron to the structural steel (A36 or equivalent)?






RE: Welding Cast Iron to Structural Steel
RE: Welding Cast Iron to Structural Steel
Welding to CI is a problem, as mentioned above. But perhaps the bigger problem is that you won't really know what kind of welds you have when you're done. This would be the case when welding to old steel, as well. You can't qualify a weld when you're welding to "mystery metal".
RE: Welding Cast Iron to Structural Steel
Thanks for the quick response. I was thinking along the same lines as your notes indicate, but I was wondering if anyone had actually made a welded connection like this.
I'm pretty sure the C.I. columns are in the 100 year old range.
Between the new steel beams and the C.I. columns is a loose 1-1/4" thick steel cap plate. I just don't feel comfortable leaving the beams sit loose on the columns as they are. I'll have to give some thought to devising a collar for the columns and perhaps bolt up to the loose plate on top. Then weld the plate to the beam.
Thanks again.
RE: Welding Cast Iron to Structural Steel
RE: Welding Cast Iron to Structural Steel
If it is wrought iron then clean and weld with an austentic stainless steel, like 308. Though don't expect it to have reliable mechanical properties. That is to say, the high Silicon slag that contained within the wrought iron microstructure could cause inclusions in the weld deposit.
If it is cast iron, find some way to BOLT it together.
Vita sine litteris mors est.
RE: Welding Cast Iron to Structural Steel
Welded repairs to cast iron are iffy at best and it sounds like you would have a heck of a time heating a column that size to a high enough temp to prevent weld tear out and cracking upon cooling.
RE: Welding Cast Iron to Structural Steel
A steel (and welable) cap that would cup the CI column and be mechanically restrained seems to offer a connection that may be analized and thus make a more dependable connection. My three and a half cents (sense).