I just rebuilt a Welch 1405 pump. MAN what a job!!! This baby was a freebie and I understand why, now! It is no great machine at just over 2CFM, but is a real cutie and a classic work horse which will, if cared for properly, give years of service.
The thing was loaded with glop and crude probably extant since it was first put into service in the 50s! What a mess.
I obtained the low level seal and rebuld kit from Dunaway for about $30.00. An entire Sunday was burned off dismantling, cleaning, sanding and repairing everything from the valves to replacing seals and gasketing.
I was at last gratified to see the thing pull down to 20 microns in under 1 minute at the head when done. I still have to run the hell out of it and go through two changes of the tko-ff flushing fluids before a final fill with good oil. (the initial pump down was done with old drained, but relatively clean oil from my good pumps.)
No fusion here, but normal PM on the machines of the fusion trade.
In this amateur biz, you gotta be research physicist, materials scientist, health safety physicist, neutron metrology guru, mathematician, engineer, technician, vacuum expert, procurement officer, .....and chief cook and bottle washer.
Richard Hull
Created on Tuesday, December 12, 2000 11:10 AM EDT by Richard Hull