Vacuum Press, Pump or Venturi ?

[Bidule]

Hello

I am a total noob in veneering and I want to build a vacuum press, for those who have been veneering before, should i go with a pump or with a venturi ?

I already have a small PC compressor so venturi seems to be cheaper.

Thx

[Legacy]

I built a small venturi-based system but doing it over I would go for a vacuum pump.

Depending on how leaky the system and bag are, the system may need to run more often to maintain the vacuum. If the source of vacuum is from a venturi then the compressor has to run as well, so this can be annoyingly noisy depending on your surroundings.

This is where I got my info for building my system. No affiliation to them.

http://www.joewoodworker.com/veneering/v2-about.htm

[billh]

I don't do vacuum veneering but I do vacuum chucking on my lathe. I have used an old dehumidifier compressor with good results although it usually only runs for lets say about 30 minutes. I have read posts around the net about people using refrigerator, freezer, portable air-conditioner, or dehumidfier compressors to veneer.

I recall one person posting a caution of using a portable fan to keep the unit cool since it will run for long periods and you don't want a thermal protection mechanism to trip it off.

The larger the compressor the better as far as handling any leakage so the air-conditioner or dehumidifier likely would be preferred over a refrigerator but I'm not certain about the relative sizing.

billh

[Bidule]

Thanks for the link Legacy. I am veneering pretty big panels, and the pump i would need is 300$ before tax and i need to add another 50$ minimum for shipping, a bit too expensive for me.
The Venturi would be around 150$ so i think ill go with that, the only problem is that i would need some "Schedule 40" 3" PVC pipe for the vacuum chamber, any idea where i could find that ?
Did you buy your hardware from Joe, including the PVC Pipe ?

[Peter in Maple Ridge]

I don't have the newsletter in front of me but Joe Woodworker is having a free shipping day. I think it's on June 26. For Canadian orders you have to spend over $250 to get the free shipping if my memory serves me correctly.

[Bidule]

I don't have the newsletter in front of me but Joe Woodworker is having a free shipping day. I think it's on June 26. For Canadian orders you have to spend over $250 to get the free shipping if my memory serves me correctly.

Hi Peter

I went to Joe's website and could not find anything about a free shipping day. Could you check that newsletter for me please, i don't have any problem spending 250$ on his store if shipping is free and it's in like 3 day !

Thanks

[Peter in Maple Ridge]

I found the newsletter. I don't know if u need to be a newsletter subscriber to get the deal. I doubt it but sign up is free regardless. Good luck with your purchase!

Newsletter:


I'm guessing that most of our newsletter subscribers are anxiously waiting for the announcement of our next free shipping day. I know how important this type of event can be and I've been "talking this up" for a couple of months. Now it's time to make good on my promise.

Free Shipping Day: Tuesday, June 26th

Continental US - Free Shipping On Orders Over $100
Alaska & Hawaii - Free Shipping On Orders Over $150
Canada - Free Shipping On Orders Over $250

To get free shipping, you must place your order on June 26th only. Don't order too soon or too late because I can't change this special in any way.

Have a great July 4th. Christine and I will be heading off again to State College Pennsylvania to watch their incredible fireworks display.

Cheers,
Joe

[Bidule]

Hey Thanks a lot Peter, looks like the timing is just perfect.

[Legacy]

Hi Bidule,

Sorry I missed your reply earlier. For the Schedule 40 PVC pipe I went to a local plumbing supply. SCH 40 defines the ID of the pipe, but be wary about buying the pipe at typical big box stores, they typically carry foam core rather than solid core. The foam core has a thin inner and outer layer of PVC sandwiching a foam layer. It is not rated for pressure (or vacuum), whereas the solid core one is. Even after getting the venturi there was still a lot of running around to get all the fittings, solenoid valve and vacuum switch. The good thing is that once you have the components, you can always change to a vacuum pump later on, with some minor changes. It just changes the source of vacuum. You can get started with veneering this way, but if you find you do it frequently, you might want to get a vacuum pump later on because of the noise from the compressor. Make your vacuum bag and all the interconnecting piping as leak free as possible.