Homemade silent air compressor

[NeiljohnUK]

Brain fart I guess. I know that the Jun-air compressors are cooled by the oil in the system. The motors run in a dielectric oil for cooling. They make about as much noise as a refrigerator and they gang compressors together to get more airflow. The insides look very much like the old York A/C compressors, only much smaller.
Products - JUN-AIR
I had one for awhile and it was a nice portable for working inside, but the tank rotted out and the compressor cap and starter was blown. Parts are not easy to find at reasonable prices.

I refurb our jun-air units at work, and part of the process is tumbling with stainless steel bolts to remove internal tank corrosion, as moist air soon becomes condensation in the tank, once done the tank gets rinsed and dried, then coated with high zinc primer, then over that goes chlorinated rubber paint which resists the carry-over oil that solvents the original internal paint. Once thats dried I perform a HYDRAULIC pressure test, never test with air/gas as a failure wouldn't do anything or anyone close by much good, before reassembly. The main compressor problem is the reed valve block suffers with corrosion from moist air, and usually needs careful cleaning and a new gasket made. The last one I serviced was being thrown away by an academic as it "wasn't working", the tank was FULL of condensate and the filter too having never been drained in 10 YEARS, after a prolonged tumble and all the rest it's back on the spares shelf ready to go when needed (we have quite a few around the labs), cost of repair, my time say £400 and some paint, the replacement cost the academic £1,500 (with discounts) so it was worth the effort to achieve a spare unit.