Have you had the shaft out of the saw and verified the bad journal? I've seen emergency repairs made with Loctite 635 and a brand called Belzona Molecular Metal. But I don't think these are permanent fixes. I don't even like my experiences with spray metal. I've seen it flake off especially on shafts that have impact, the spray metal cracks and then flakes off.

I'd rather see the shaft cut off and a stub welded on then turned to the proper dimensions.