Hello, all,

I have a Peck, Stowe and Wilcox 30" shear that has a crack in the platen
(The "bed" of the unit that holds the fixed blade). It first cracked
right across where one of the bolts that supports the fixed blade is,
parallel to that bolt. This is the vertical bolt that presses upward on
the bottom of the fixed blade, not the bolts that clamp the blade to the
platen.

Anyway, someone had made a horribly amateur attempt at welding it, and
it cracked immediately. I took a shot at TIG welding the crack, knowing
it had about zero chance of working. Exactly. So, then I welded a
piece of 1/4" steel plate about 6" long, underneath the rib of the
platen, running about 3" each side of the crack. I made a number of
small weld beads there, essentially butt welding the plate onto the edge
of the rib. (The plate hangs straight down from the platen.) I used
TIG at ~100 amps (had the welder set for 150 A max) and went slow so as
to at least partially preheat the area, and then just make a 1/2" long
bead at a time. This weld has held quite nicely!

But (there's always a but) now the platen has cracked again, right at
the end of the welded area. This is right down the center of the platen
too, heading toward the front of the platen, where you stand to stomp
on the pedal. (There is a possibility this crack was already there, or
at least starting to develop, and when the other crack was secured, the
load all jumped to this one. But, the location RIGHT at the end of my
weld is suspicious.)


Well, I certainly don't have a heat treat oven where I can preheat
something as big as this. Has anyone ever succedded in repairing cracks
on a stomp shear like this? Especially if it is a Peck, Stowe & Wilcox,
(not their later PEXTO label) so it must be PRETTY old, I'm guessing
1900 - 1920 at the latest. (Hope this thing isn't made of the same iron
that went into the Titanic! That would explain this damn thing cracking
so easily.) And, of course, the real question is, should I try to
repair this crack, too, or is this a totally lost cause? Without a heat
treat oven, is every weld repair going to end up producing another crack?

Thanks in advance for any thoughts on this!

Jon