This project will convert a (free) air compress into a vacuum pump to be used when vacuum bagging veneers and other such tasks.

It is sad when perfectly good tools, or any other items are put to the curb, and that was the case with this Central Pneumatic (harbor freight) 2HP 5 gallon compressor.
I expected the compressor have have been broken and not in working condition, however, I plugged it in and away it ran. Pumps up, holds air… off to a good start!

Next was to figure out how to change a tool known to build pressure, into a tool to create vacuum.
Actually, it was very easy and nondestructive. The modification allows the compressor to remain a compressor, and be a vacuum pump.

All that was needed for this modification was to remove the air intake filter, and create a flange/manifold that would allow a vacuum hose to be attached.
I used some scrape steel, and a short piece of steel tubing, cut everything to size, drilled appropriate holes for mounting and such. Then inserted the pipe in the new flange, gave it a quick weld just to ensure a seal between the two pieces, then cut some gasket material.
Initially I used some sheet cork as a gasket, but I was concerned the cork would flake and be drawn into the compressor, so after an initial test, I cut a new gasket from some hightemp silicone sheet. Much better!

At this point I wanted to test the compressorvac in a real life situation. I hooked the “vac” up to a vacuum bag to verify it would evacuate the bag and draw enough pressure… YES, it works perfectly.
The compressor will draw the vacuum bag down to ± 21Hg in about 10 seconds, and 23Hg in about 15 seconds.

This was a very simple project, maybe took 2 hours once I figured out how I wanted to go about it.

In the future, I may rig up a pressure switch, so the compressor will cycle on and off automatically to ensure a consistent bag pressure. Or, maybe I’ll just use it as is.

I hope you enjoy the video, please leave a comment, subscribe, ring the bell… now go build something!