Making a Vacuum Bag

[Tenson]

I had good success with my vac bag.



I used this PVC - eBay item number: 252175735357

I then tested various glues including PVC pipe cement and opted to use cyanoacrylate (superglue). I used medium viscosity 'BontIt' from here - eBay item number:140938448838

I found the superglue tacked within a few seconds of contact which made assembly of the seams reasonably easy. If you fold the PVC over to make a seam it wants to spring back, so fast initial bond is helpful. After an hour of setting it is very strong indeed, but remains flexible enough to fold the bag for storage.

Regarding the seams, I cut the main bag piece and folded it in half. I then put a line of glue down the left and right sides to join the edges and kept one end open as the mouth of the bag. Make sure you start glueing from the closed / folded-over end of the bag and work your way towards the open end. Follow this I then cut two long strips of PVC and folded them over the left and right edges of the bag with more glue to give greater strength. Make sure these pieces overlap the closed end of the bag because I left a tiny bit exposed and it wanted to leak air at the corner of the main bag fold.



For vacuum tube entry I use a male 'pneumatic / air line' push fitting for 10mm tubing (eBay item: 271290823788). To attach it in the bag I cut 2x pieces of 5mm acrylic in a disc shape with a hole in the middle. I threaded the air-line fitting into one and bonded it inside the bag, with the air-line fitting sticking out through a hole. Then I placed the other acrylic disc (with a slight bigger central hole) over the top to sandwich with the bag material. Basically the two discs hold the bag material between them and I threaded the push fitting into the bottom disc.

I also put a one way / non-return valve (eBay item: 121665943577) in the air line so I can disconnect from the vacuum pump without loss of vacuum.

To close the mouth of the bag I simply fold it over twice and clamp it between two strips of wood using g-clamps.