Discussion Forum

question about vacuum presses

gedaliahblum | Posted in General Discussion on May 10, 2006 09:44am

I am looking to make a vacuum press. My question is how.

I would appreciate any home made plans or ideas. Thanks.

Gedaliah

Replies

JimV | May 10, 2006 10:10pm | #1
Check http://www.joewoodworker.com

Not affliated, just a satisfied customer.

gedaliahblum | May 12, 2006 06:50pm | #4
I don't understand the website. do you buy all the parts seporatly and then put it together? Do they sell presses ready to use? One more thing, this may be a question for the manufacturer, but do they sell them in 220v?

Thanks for the replys

JohnWW | May 13, 2006 02:26am | #6
You can get some vacuum pumps in 220 but the smaller pumps don't draw a lot of power so there is little advantage to be gained.

Vacuum presses are often sold as separate components because they basically are separate components. That way you can buy the bag to suit the specific application you have in mind while the pump can be chosen based on budget and projected needs.

John White, Shop Manager, Fine Woodworking Magazine
John_D | May 13, 2006 07:15am | #7
If you already have a compressor (or are considering buying one), you could consider a venturi, which doesn't require its own motor. Obviously there are plenty of compressors that run on 220 -- of course I don't have any idea if they're happy with 50Hz.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.

citrouille | May 13, 2006 07:14pm | #8
John,I have a Venturi pump, I bought it about 15 years ago for something like $8.
It is as big as a lipstick tube and does a great job.
Now I see more or less the same thing adverised for more than $50.
Is what they sell now better ? How ?C.

dgreen | May 13, 2006 09:09pm | #9
Falling value of the dollar, the more they print the less it's worth.
John_D | May 13, 2006 11:06pm | #10
I don't know of any reason you should abandon what's working for you. I was responding to gedaliabloom, who was looking for a vacuum pump that would work on her 230v 50hz juice -- thus the suggestion for a venturi (assuming she had or wanted a compressor).My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
citrouille | May 14, 2006 02:29pm | #12
Since you were familiar with Venturi pumps, I was wondering if there was an evolution that would justify the jump in price.C.
John_D | May 14, 2006 09:59pm | #14
I think the one you're describing has no meter, etc. It simply creates vacuum when compressed air goes through, with the vacuum produced dependent on the feed PSI. More sophisticated models can actually maintain a specific vacuum level, checking the pressure and keeping it constant -- but those might require 110v, negating the advantage applicable to gedaliabloom. Maybe you should buy one of the fancy new ones and ship your old one to Israel. Heh.

I guess the difference between yours and the more sophisticated models is sort of like the difference between a continuous-run pump like those in the skateboard veneering presses, and a pump that maintains a specific vacuum level by monitoring and cycling.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.

Ronaway | May 10, 2006 11:50pm | #2
Joe Woodworker is the guy, another satisfied customer.

Ron
KeithNewton | May 11, 2006 05:05am | #3
Replace the intake filter on your air-compressor with fittings to hose-barb > hose, and open the tank drain.

Go to Walmart or Lows, and get a box of clear drum size plastic liners, and cut a small hole in one corner of the bag, and shove the hose through. Then take a wad of something gummy like rope-caulk, and wind it around the hose, and pull it back down to the corner, and squeeze the plastic to conform tightly around it. You can make bigger bags with vinyl and carpet tape, or the glue made for this purpose. Or you can order a made up bag.

Tape a piece of rag onto the end of the hose, and make sure that that provides a pathway for air to move from the work to the end of the hose.

Seal the open end of the bag by rolling up the end between to battens with spring clamps pinching it together.

You may want to take the tubing line between the pump and tank loose the first time, so you will know if the oil is being pulled out of the crank-case around the rings. Feel of the pump and motor every 20 minutes or so to make sure it is running cool.

If your pump is good you should get a ton of pressure for each square-foot of surface area on the bag. You can rig up a pressure switch if you like, but the motor is doing very little work. It can only pump minus 14 psi at sea-level.
LesT | May 12, 2006 10:10pm | #5
I don't know if you're going to build one because of cost or the fact you just want to, but if it's a cost issue you might look at rockler.com and search on 'vacuum press kit' or go directly to http://www.roarockit.com. I've used the system for smaller projects and it works great. I use the shop vac to exhaust most of the air in bag and then the little hand pump to really put the pressure on. Would like to know if anyone else has used the system and what they think...
mufti | May 13, 2006 11:30pm | #11
If you know anyone working in scientific research they may have access to vacuum pumps no longer suitable for their purposes. When working I rescued various pumps from the scrap and they work well. The only downside is some I cannot lift! Good luck.
CSvarstad | May 14, 2006 05:14pm | #13
I made my pump from a salvaged de-humidifier, a few simple parts from Radio Shack.....relay, and a vacume switch from Aerospace Composites. Probably spent less than $30, works great.