A closer look at Rollie’s budget vacuum pump
How to clamp and press on a woodworker’s budget
In the last episode of Talking Tools, I showed how to build quick and easy vacuum clamps. In answer to a reader’s question, I said I would outline my pump setup in the next Talking Tools. So here it is.
The pump I use is a Welch Duo-Seal that I bought from a university lab. The university was cleaning out excess equipment and I paid $50 for the pump. It’s a bit of an oldie, probably from the 1980s, but it had been rebuilt and was in fine working order. And it was a pretty good deal for a pump that still sells new for $2,990. That’s the beauty of this system; there are lots of good used vacuum pumps that go for little money and they are pretty bulletproof. I just checked eBay and my local Craigslist and found a couple of Welch pumps for under $150 and some smaller pumps as cheap as $30.
The rest of the setup is pretty straightforward. I bought everything but the duplex switch and supply tank from Veneer Supplies. Here’s the list of supplies that you will need:
- H.D. vacuum gauge 1/4-in. NPT
- Vacuum controller 1/8-in. NPT
- 30-amp vacuum control relay
- H.D. check valve 1/4-in. NPT (in and out)
- Vacuum damper for large pump (only needed if you score a large pump, won’t need if you have a small pump)
- Inline vacuum pump filter (40 micron)
- Ball valve 1/4-in. NPT
- Leviton 5245 Duplex Style 3-way combo switch/receptacle 15 amp
- New 20-lb. propane tank
- 3 – 1/4-in. NPT cast Tee
- 2 – 1/4-in. NPT to 3/8-in. barbed fitting
- 1 – 1 in. 1/4 NPT nipple
- 1/4-in. NPT to 1/8-in. NPT reducer (for vacuum controller/vacuum adapter)
- 3/8-in. braided HD plastic hose (a foot or so)
- Adapter for propane tank to 1/4-in. NPT male
It looks like a lot of stuff but you can buy the works new for under $200. One word of caution: Don’t try to repurpose a used propane tank. I had one I wasn’t using, cleaned it out with some solvent, then soap and water, and proceeded to foul the air in my shop the first time I used the system. The scent in propane is from Ethyl Mercaptan and it’s about impossible to clean it all out, and it stinks. So spend the $25 and keep your shop smelling sweet.
Notice that I use a quick-coupler after the ball valve for attaching my vacuum hose. I use a hydraulic 2-way quick coupler; they work with positive or negative pressure so I can disconnect a vacuum bag without losing the vacuum. A barbed fitting will work, but not as easily.
When you wire the system, use a single pole switch to control the power to the setup. The duplex 3-way switch is wired so one side controls the motor directly from the power source for continuous operation and the other side controls the vacuum switch/vacuum control relay. The relay fits next to the duplex switch in the deep box. There are good wiring diagrams on the Veneer Supplies site.
I built my setup as compact as possible and mounted it on some large casters (two fixed, two steerable) so it will roll over extension cords and work mats easily.
I’d like to give a shout-out to my good friend Dr. Glenn Street, who was the inspiration and wiring guru for the system.