I have a 5 gallon air pig that I want to use as a reservoir for vacuum bagging, so the vacuum pump isn't cycling on and off so much.

It's a standard one with a gauge, hose and a bleed valve for letting out the pressure. I removed the hose and put a straight connector for allowing excavation of pressure (vacuum) into the container.

Am I correct in assuming that when I removed the hose that there is no valves or anything between the opening and the tank?

You might find the airpig implodes as they are designed for pressure not vacuum. Just something to ponder.

If it were to be compromised it would likely just leak and then leak quickly. I doubt it would be an issue due to the shape of the vessel.

what's an air pig?

Sorry, I am just used to calling a compressor air reservoir a pig. It looks like a pig.

http://www.princessauto.com/pal/product/0430603/

I've been using a 7gal tank and it works great. Pump is on for one minute, off for 15. Makes a big difference.

What do you use as a switcher?

I use a custom switch built from a 220v 21 amp micro switch and a "flavor injector" syringe that you can buy at stores like kmart or walmart. I have rubber bands pulling the plunger against the switch. When the vacuum overcomes the pull of the bands, it pulls the plunger away from the switch. I can adjust the number of bands to get it to switch on and off at different levels. The bands stretch out over time, so I may switch to a spring. Wired to the switch I have a 3 prong grounded recept. and a grounded power cord.

Put in an offer on this. Adjustable setpoint, adjustable deadband (difference between 'off' and 'on' thresholds), plug-and-play. Overkill, yes. But no effing around with syringes, pneumatic cylinders, springs and micro-switches. Not my ad.

http://www.ebay.ca/itm/Barksdale-Pressure-Switch-E1H-H-VAC-P6-Vacuum-Actuated-/180765056240?pt=LH_DefaultDomain_0&hash=item2a166fdcf0#ht_517wt_932

http://www.barksdale.com/download/?dl=503

I use http://www.smcpneumatics.com/ZSE1-01-14.html (cheap from ebay). Great, but complicated electrical setup.

Rob

Hola, I don’t think there will be any risk of implosion with the compressor reservoir. An air pig is used as an air manifold which is usually a cylindrical or donut shaped reservoir with multiple air connectors making it look like a sow (female pig). The multiple connectors resemble nipples and thus the name. Regarding cycling vacuum pumps I reckon that you are missing the point of a vacuum. If you have a leak it is no good. Your work will be compromised and the leak will migrate resin and weaken your work. If the pressure has nowhere to go nothing gets displaced inside the bag. It is a matter of getting better at making leak free set ups. I wish there was a substitute for tacky tape but I have tried and I only manage perfect seals with the proper set up. Your work will benefit from the extra bagging effort!

Good winds.......

WjM................