Yesterday I had a troublesome setback with a leaking HP seat. Seats for 1942 model Bendix Oxygen regulators aren't generally available at your local dive boutique... but that won't keep me from going in with the reg and harassing them anyway.
Pulled the first stage apart and found that the fairly soft cone-shaped seating surface had been nicked by some little unidentifiable metal particle, but luckily the brass orifice appeared undamaged. The seat is odd-shaped and not readily resurfaced the way we do flat-faced ones from early Aqualung type regs. I was faced with attempting a repair with my little Unimat mini-lathe that I keep tucked on a shelf under my larger unit. I would have to remove several thousandths to reshape the cone, preserving the correct angles and hoping I didn't totally destroy it. Having to make a whole new one from scratch would be really challenging considering my limited machinist skills, so I was pretty worried about the whole situation. I could just see this whole pet project crumbling around me, but then confidence was bolstered somewhat by remembering the words of a wise friend: "Don't borrow trouble before it happens!"
Working slowly I removed about 0.0005" at a time until the flaw was no longer visible, then used a small strip of 600 paper over the tool edge to polish the tiny cone slightly. Next step was modifying a modern reg inlet filter to fit into the Bendix inlet, hoping that would help prevent a debris particle from ever reaching the seat again. That was easy.
Reassembled the first stage and the pressure is now holding perfectly, so I'll be going diving with this rig as soon as time and weather permit.
You do not have the required permissions to view the files attached to this post.