I have a 5 hp leaf blower that has an aluminum hub for the fan/impeller.
It has wallowed out, both in the keyway and bore, so I decided to make
a new one from steel. I had a piece of 12L14 that was just-right and I
turned, bored, and reamed it for a perfect fit. The hub needs a cross
piece for bolting on the fan and I made it from a piece of 1/4 x 1-1/2
mystery steel.

It all fit up real nice and I was all ready weld them together when I
had an "Oh, crap" moment: one can't weld 12L14. (Or so I've heard - the
weld is supposedly real crappy from the lead.)

Assuming that welding is a bad idea, can I silver solder them? The
cross piece sits on a shoulder on the hub, with a matching surface
that's 3/16 wide & 1-1/2" diameter and a cylindrical contact of 1/4 x
1-1/8 diameter. Nearly 2 square inches of contact.

The basic question is: will the lead affect the solder? Having the fan
come off at 3000 rpm is not the kind of excitement that I need.

Bob