Anyone using a reserve tank on their vacuum chuck?

[Jeffrey J Smith]

I've been toying with the idea of adding a reserve tank to my vacuum system - thought I'd mine the creek for your ideas. The idea first developed when the thermocouple on my Gast pump kicked in one particularly hot day this summer and turned the lathe into a potential launching pad. The tool rest kept it from going too far, and no real damage was done except that I had to take the time to get the piece centered again...

I've been looking for someone with a dead compressor to take the tank from when I thought to look on HF's website and discovered both 5 gallon and 11 gallon tanks for sale at a reasonable price. Seems like a good solution.

Before I invest, thought I'd ask - how many of you have a reserve tank as part of your system? Is it worth the time to setup? Is there a downside besides a potential lag in the startup time of the system while the tank charges? Will I need a check valve between the tank and the pump?

Any help appreciated...

Jeff

[Don McClure]

I built my system a couple of years ago and included a reserve tank just for such events as you had. It gives you more time to shut things down safely. I used an 5 gallon air tank from an auto parts store at a cost of around $30. Several members in my club have used old freon or refigereant tanks. I have not had any significant lags at start up.I don't know of any draw backs, but others may know of some.

[John Spitters]

I have a 3 gallon tank from an old hotdog compressor, with no checkvalve between. I would say that depending on the porosity of the wood I get an extra 10 - 15 seconds to grab the piece before it gets launched across the shop.

John

[John King]

Check valve in vacuum line to chuck is a lot cheaper and requires less space than tank. Good check valve will hold vacuum long enough for safe shutdown of lathe. Check it out at http://www.mcmaster.com/#standard-check-valves/=k0u7ik. - John

PS - It's item no. 4610K17. - J

[Josh Bowman]

John,
Have you tried a shutdown and see how long the vacuum lasts? This sure sounds like an easy fix. I realize it's up to the porosity of the wood, but assuming something like cherry or maple, I'm wondering about the hold time.

[Dick Mahany]

When I was making a vacuum bag press, I came across many excellent reserve tank ideas that simply used 3-4"schedule 40 PVC pipe sections 2-3 ft long with end caps glued on. The pipes were connected to each other using brass fittings and nylon tubing all readily available at the local hardwareplumbing store. I like the idea of a used pressure tank, but this alternative seemed to work well if needed. Of course the PVC could never be used for pressure, only for vacuum.

[John King]

Josh - Have not tried it. Got the tip from Glenn Lucas (http://glennlucas.com/). He says it works great. - John