lurker":3ar4lnly said:I am a bit perplexed about the concept of cast iron flexing.
I don't profess to be an expert on such matters, but can't see it myself on a big lump like a 5 with a little bit knocked out of it.
Certainly I would not bin it, as sooner or later it's a donor.
Quite. In normal use, there's no need to bear down heavily on a plane. Indeed, there's a YouTube video by Paul Sellers where he planes an edge by pulling a plane along with a bit of string round the front knob only. Not much flexing of the casting going on there, I suggest.
If the OP wants to repair the side and hasn't already glued the bits back, he could consider attaching a little splint to the outside. As on this old no 4 of mine (apologies to those who have seen this before).