Making a Vacuum Bag Connector (Vacuum Port) for $10 With Hardware Store Parts

In this instructable I'll show you how to make a vacuum bag stem (also called a vacuum breach valve/unit). These are important in vacuum bagging because taping the hose on the seam of the bag is a recipe for leaks and disaster.

This adds on to the excellent guide on vacuum bagging basics
It also goes well with the bicycle-turned-vacuum pump guide if you want to do some hand powered vacuum bagging, or the great tire-inflator-turned-vacuum-pump guide.

Gather Your Parts

You'll need:
4 3/8" steel washers
2 3/8" ID, 7/8" OD neoprene washers
1 1/8" F nut (dunno what they're called)
1 1/8" M to M threaded tube connector (the shorter the better)
1 1/8" F NPT to hose connector
Vacuum bagging plastic sheet/film

Assemble Everything

You're going to need to assemble the parts in the following order:
Rubber tube connector, M M threaded connector, 3 steel washers, 1 neoprene washer, plastic to be vacuum bagged, 1 neoprene washer, 1 steel washer, nut.

Note: When you put the vacuum bagging material on you will need to punch a hole in the bag to get the tube through. Make sure this hole is smaller than the tube, and stretch it around the tube to help prevent leaks.

Done! Enjoy Your Breach Valve

There it is!
On a side note: The neoprene washers should be a tight fit around the tube. This is good because if it doesn't happen, you'll have air leaking around the rubber and killing your vacuum.