Making a Vacuum press

[flanajb]

A google search reveals this is possible, but anyone of the forum made one ?

 

[Chems]

I haven't, but this is a good video of how too from the wood whisperer:

http://thewoodwhisperer.com/tag/vacuum-press/

He talks about what materials not to use and such.

 

[Dibs-h]

Vacuum presses - most of the Carbon Fibre folk I know make their own. All the stuff is readily available - I'd go so far as saying, I've not come across someone in that field who's bought one.

By press - I mean the "thingy" you put your parts\etc into. It's on my list of things to do, somewhere in the 200+ range - so it'll be a while yet. :lol:

 

[xy mosian]

I've not needed one ... yet. But I keep looking at the bags that swmbo has for scrunching even more stuff in to the case when we go on holiday. The largest one we/she has will easily take a suit on a hanger.

xy

 

[flanajb]

I've not needed one ... yet. But I keep looking at the bags that swmbo has for scrunching even more stuff in to the case when we go on holiday. The largest one we/she has will easily take a suit on a hanger.

xy

But if you vacuum press all your clothes on the way out, how do you pack the case on the way bag. Do you take the compressor with you :?

 

[Steve Maskery]

I've been using just such a bag today, as I couldn't be bothered to get the vac bag and pump out. These use an ordinary domestic vacuum cleaner and I have to say, on an ordinary flat unchallenging panel the results were great! Very quick, too, as a vac cleaner shifts air much more quickly than a pump (but not, of course, to such a low pressure).

I'm very happy.
(With that, anyway).
S

 

[xy mosian]

flanajb,
Muggins here normally ends up sitting on the thing!

Thanks for the post Steve, at least the idea is not as daft as I thought it might be.

xy

 

[Chems]

I've been using just such a bag today, as I couldn't be bothered to get the vac bag and pump out. These use an ordinary domestic vacuum cleaner and I have to say, on an ordinary flat unchallenging panel the results were great! Very quick, too, as a vac cleaner shifts air much more quickly than a pump (but not, of course, to such a low pressure).

I'm very happy.
(With that, anyway).
S

Could you combine a shop vac to do the donkeys work and finish off with a hand pump?

 

[Steve Maskery]

I've no idea, Chems. On this one there is no connection for a vac hose, not as such, it relies on the bag and the nozzle kissing each other passionately...
S

 

[rileytoolworks]

Chems, I see no reason why this shouldn't work. The problem would be air migrating INTO the bag during the switchover from vac to pump. (I've fitted a non return valve to my bag). Ceck out skateboard builds on Youtube.
Steve, I don't want to brag, but my vac pump shifts 40m3 per hour!!!!!
It evacuates a bag pretty quickly, I can tell you...


Adam.

 

[TheTiddles]

You really, really don't need a big pump to do these things, a pump with a few litres/minute may take a couple of minutes to draw down the bag but once it's evacuated there's almost no flow so a high-flow pump is not necessary. The major advantage to have is a pressure switch to turn the pump on when it's needed, other than that you can make one for very little. Mine was free, but I work with vacuum pumps every day. I have a few little pumps kicking around that we have sometimes kept running for months pulling an 80% vacuum

Aidan

 

[rileytoolworks]

I agree wholeheartedly that a fast evacuation is way less important than max vacuum level, but I regularly press up 2.5 metre+ bent laminations, sometimes as many as 12 plies, and in that situation, time is of the essence.
I use a smaller vac pump for smallish flat panels, it will only pull 20"HG, but I've not had any problems with that.
The big pump will pull 28"Hg.
I also have a Devilbiss Suction Unit (used to suck fluids out of post op patients - yeuch) which I used to use but now less so.
Thoroughly enjoy working with vacuum and would love to build a frame press if I had the space.
Chems, the day I picked up the shoulder plane, I had the big pump and bag in the car. IF i'd have known you were interested, you could have had a play.
If you want a go with it, just holler.

Adam.

 

[Eric The Viking]

I work with vacuum pumps every day. I have a few little pumps kicking around that we have sometimes kept running for months pulling an 80% vacuum

Aidan

I've been wondering about a peristaltic pump for this application, and also wondering if I could make one. The tubing is available on eBay (presumably it has to be special because of the flexing).

Thoughts?

 

[TheTiddles]

I work with vacuum pumps every day. I have a few little pumps kicking around that we have sometimes kept running for months pulling an 80% vacuum

Aidan

I've been wondering about a peristaltic pump for this application, and also wondering if I could make one. The tubing is available on eBay (presumably it has to be special because of the flexing).

Thoughts?

No.

 

[TheTiddles]

I work with vacuum pumps every day. I have a few little pumps kicking around that we have sometimes kept running for months pulling an 80% vacuum

Aidan

I've been wondering about a peristaltic pump for this application, and also wondering if I could make one. The tubing is available on eBay (presumably it has to be special because of the flexing).

Thoughts?

A more expansive answer would be...

Peristaltics are great pumps but for this application a piston or diaphragm pump is better suited, able to shift much more gas faster and without needing the tube connection which wears out rapidly if you don't get the conditions right. Covering them in grease is a good idea but messy in a woodwork application.

Aidan

 

[CNC Paul]

I've been using just such a bag today, as I couldn't be bothered to get the vac bag and pump out. These use an ordinary domestic vacuum cleaner and I have to say, on an ordinary flat unchallenging panel the results were great! Very quick, too, as a vac cleaner shifts air much more quickly than a pump (but not, of course, to such a low pressure).

I'm very happy.
(With that, anyway).
S

Could you combine a shop vac to do the donkeys work and finish off with a hand pump?

Chems,

Yes you can, Bagpress do a bag outlet with a cap for a vacuum cleaner to remove most of the air quickly and a connector for the normal vacuum pump

 

[RogerM]

I've been looking towards making my own vacuum press as well. Whilst I'm considering using cauls and curved pressure bearers between G-Clamps at the moment, I can't help wondering whether for larger pieces - say 5ft x 2 ' 6" - this is going to be very hard work, and maybe difficult to get fully wound on whilst the glue remains workable. Whilst I'm sure the Bagpress is a great piece of kit I really can't justify spending north of £600 on a piece of kit that I may only use 4 or 5 times a year - particularly having just bought a new bandsaw!

I've been reading around the subject, especially Joe Woodworker and like most have found the articles on using refrigerator pumps. A halfway house might be something like this perhaps? 3 cfm should be enough to evacuate a bag for flat work quickly enough shouldn't it? Anyone using something like this? And where do I get things like a vacuum guage and pressure switch from?

Any ideas gratefully received.

Regards,

Roger