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

25,462

50

12

Intro: 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.

Step 1: 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

Step 2: 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. 

Step 3: 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. 

Share

    Recommendations

    • Furniture Contest 2018

      Furniture Contest 2018
    • Fix It! Contest

      Fix It! Contest
    • Tiny Home Contest

      Tiny Home Contest

    12 Discussions

    0
    None
    JaakkoP1

    8 months ago

    This isn't very good solution. You need to solder the first washer(s) to the brass hose connector, then you are able to block the air leaking when there isnt any route to pass the gasget(s). This way you need only one gasget.

    Untitled.png
    0
    None
    coultervm

    2 years ago

    I just ordered a valve on amazon with a hand pump. It is usually used to keep whine fresh, but i got 4 "valves" and a small pump for around 10$. They are nearly identical to the ones used by Roarockit.

    0
    None
    tim.nagy

    4 years ago on Introduction

    solder (or weld) the washers together to make handling it all easier

    0
    None
    DB.Cooper

    4 years ago on Introduction

    great instructable, purpose driven, simple enough for anyone to do.

    If I may ask, would this not be a port instead of a valve? And am I to assume that this is for a short term project use - such as vacuum forming, or impregnating a fluid in a material such as with carbon fiber?

    Would it be possible to create a valve by cutting an extra piece of rubber that opens during the draw out, but closes against the other washer to generate a seal; such as one would find in a blacksmith's bellow's?

    1 reply
    0
    None
    cpederkoffDB.Cooper

    Reply 4 years ago on Introduction

    You're absolutely right, it is a port instead of a valve. It should be called a vacuum connector or a vacuum port instead.

    And you're right! It is for short-term project use like vacuum forming or vacuum bagging carbon fiber or fiberglass.

    I haven't given the rubber seal much thought. The trick is that the flap would need to be on the outside, not the inside to let air go the right way.

    0
    None
    vincent7520

    5 years ago on Introduction

    ???
    how air isn't sucked in through the valve ?
    Does it has a flap inside or something ?
    The hose connector is hollow, no ?…

    Don't get the idea at all !…

    sorry…

    2 replies
    0
    None
    cpederkoffvincent7520

    Reply 5 years ago on Introduction

    You're right, it doesn't have any sort of one-way valve on it. The trick would be to leave the hose on for the duration of time that you need a vacuum.

    0
    None
    gomibakou

    5 years ago on Introduction

    What if you place another washer outside and clamp the plastic in middle of them? it should stop any leak...

    //////////// <---- neoprene washer
    ----------------- <- plastic
    //////////// <---- neoprene washer


    It should help for a better tighting...

    1 reply
    0
    None
    cpederkoffgomibakou

    Reply 5 years ago on Introduction

    Hmm that is a good idea, and what I think I'm doing, if I read your comment correctly. The plastic is held on both sides by neoprene washers, and outside of both of those are two steel washers which distribute the tightening pressure from the three brass fittings.

    0
    None
    Mindmapper1

    5 years ago on Introduction

    mmm this cant work in the way you have described or shown. How does the air not flood back in when you remove the hose? there needs to be some kind of oneway valve. can you show this working?

    1 reply
    0
    None
    cpederkoffMindmapper1

    Reply 5 years ago on Introduction

    You're absolutely right! I was using drcrash's manual vacuum pump which has on it a one way ball valve. 
    Though that doesn't fix the problem of air flooding back in when I remove the hose. I just leave the hose on and maintaining the vacuum for as long as I need it and then remove the hose.