Here is one of hundreds of Vacuum operated advance unit diaphragm replacements that I have done. After years of use, the rubber in these units shrinks, becomes rigid, pulls-out of its crimped metal seam, or otherwise deteriorates.
 Using a nylon mesh reinforced  nitrile diaphragm material,  I replace old rotten components using a variety of suitable techniques.  By wrapping the diaphragm material around the crimped components perimeter, I do OEM one step better. My diaphragm will never pull out of a crimped seam, as often is the case on OEM units.

This old hand held vacuum pump has seen a lot of use. It is still accurate! Here is the repaired vacuum canister holding about 20 "Hg. without leaks. 
   When I say "Hundreds of units repaired", this is actually an understatement. I have repaired so many over the years that I have lost count. Here are a few unusual ones finished.
Something weird about this work--
  The hydrocarbon aroma, ( or smells - depending upon your point of view) that accompany the opening of these old units is somewhat akin to their DNA signatures.  Catching a whiff of some of these would spin the memories of some old timers back 90 years or more.!

After electroplating the bead blasted canister halves in Zinc, using a rolling press, the re-crimped canister holds vacuum once again with modern Nitrile diaphragm installed.


Nickle arc welding cast iron was a standard practice- yet often fails, as did this repair. Typically, the weld puddle comes out OK, but the cast iron next to the bead got so hot, it crystallizes the iron, and when it cools again after several heat cycles- it cracks.
  Forge brazing is a process using a lower temperature alloy rod to repair cast iron cracks that involves heating the entire manifold to eliminate local stresses in the cast iron.

You can see the cracks formed at the edge of the nickle weld where it meets the original cast iron.

Using a special cast iron alloy from MuggyWeld.com  and controlled heat on an asbestos table- baffling the assembly on all sides, I made a tent to keep the entire unit very hot- then concentrated on overfilling the area with alloy. 
  Here you see the finished product  where I cut to shape the overfill with a round-nose burr on a die grinder WHILE IT was still hot and cooling.  An "Old Timer" told me that vibration of the unit during cooling helps re-set the crystal structure of the cast iron. I do not know if that is magic, yet I have more than 50 repairs like this in the field without failure.