Part 1
Introduction
Welcome
Veneering Basics
14 Good Reasons
Vacuum Press Uses
Vacuum Press Options
Overview
Questions & Answers
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Part 2a (Option 1 of 2)
Project: V2 Venturi Press
About Project: V2
Parts List
Build the Manifold
Build the Reservoirs
Assemble the Venturi
Make the Carrier
Wire the Press
Testing and Adjusting
Mods and Options
____________________
Part 2b (Option 2 of 2)
Project: EVS Pump Press
About Project: EVS
Parts List
Pump Selection
Build the Manifold
Build the Sub-Manifold
Build the Reservoirs
Make the Carrier
Final Assembly
Wire the Press
Testing and Adjusting
Mods and Options
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Part 3
Vacuum Bagging
Vacuum Bag Basics
Polyurethane vs. Vinyl
DIY Vacuum Bags (A)
DIY Vacuum Bags (B)
DIY Vacuum Bags (C)
Connect the Bag
Bag Closures
Platens/Cauls
Breather Mesh
Maintenance
DIY Frame Press
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Part 4
Veneer Information
About Veneer
Veneering Myths
Backer Veneer
Veneer Glues
Veneering Tips
Substrate Materials
Flattening Veneers
A Sharp Veneer Saw
Jointing Veneers
Taping Veneers
Dealing with Defects
Curing Glued Panels
Veneering w/o Vacuum
Hammer Veneering
Iron-On Veneering
Veneer Storage
Amazing Bookmatches
Copper Veneer Guide
Paperbacked Veneer
Edgebanding Guide
____________________
Part 5
Miscellaneous Info
Vacuum Forming
Vacuum Chucking
Vacuum Clamping
Vacuum Clamp Matrix
Vacuum Infusing
DIY Vacuum Manifold
JWW Visitors' Vacs
Veneer Quality
Veneering FAQ
Veneer Glue FAQ
The Vac FAQ
Downloads (PDF's)

Information Type: Adjustable Auto-Cycling Vacuum: Air Powered Venturi Page: 8 of 9

Final Pneumatic Connections & System Testing

You're almost done! Within the next few minutes you'll be ready to run the veneer press!

1. Cut the black vacuum tubing to fit from the vacuum controller to the brass barbed fitting on the lower end of the manifold assembly and attach it snugly.
2. Now cut a piece of black tubing and connect it between the vacuum port on the venturi and the barbed fitting above the check valve on the manifold.
3. Attach the lock-on connector to the 1/4 NPT brass barbed fitting. Don't forget to wrap the threads with sealing tape.
4. Attach the braided vacuum tube to the vacuum valve on the manifold
5. Slide on the lock-on vacuum connector to the other end.

The final assembly should appear as shown in the picture below.

Testing and Adjustment
Set your air compressor to put out 95 to 100 psi and attach your compressed air line to the quick connector on the Mac valve. It is ok if your compressor is putting out more than 100 psi. No air should flow through yet. Next, close the vacuum valve by turning the handle to the left or right until it stops.

Notice that there is a small plastic cap on the vacuum controller just in front of the "common" tab. Under this cap is a black plastic slotted set screw where the adjustment is made for the amount of vacuum inside the system. Using a flat-head screwdriver, turn the set screw counter-clockwise until it is approximately 3/16" from the top edge of the vacuum controller body. In other words, there should be about 3/16" of the female threads visible when you look inside the adjustment area of the unit.

With the light switch on the vacuum press turned off, plug the electrical cord into your wall socket. Flip the switch and air should begin flowing through the venturi and the needle on the vacuum gauge should rise. The vacuum controller should shut off before it reaches 21" of Hg.

For the next stage of testing, you will want to carefully adjust the vacuum setting to 21". Slowly turn the adjusting screw counter-clockwise until the unit creates 21" of vacuum and cycles off. Remember counterclockwise turns of the screw will increase the amount of vacuum required before the vacuum controller will turn off the air pressure at the Mac valve. I've found that most often, 21" of Hg is when there is about 1/8" of threads showing above the adjustment screw.

It will automatically cycle on again when the vacuum has decreased. You can test this by opening the vacuum valve and releasing a bit of pressure from the system. The manufacturer of the vacuum controller claims that the controller will cycle back to the "on" mode within 4" of Hg decrease. This 4" amount of "differential" is not adjustable. In my opinion, this constant increase and decrease in vacuum pressure inside the press bag allows for an even greater bond of the veneer to the substrate.

For venturi systems, the frequent on and off cycling is harmless. During normal operation of a tightly sealed unit, it is still common to have the unit cycle on every 10 minutes for 5 - 8 seconds.

Close the vacuum valve and allow the system to recharge. Watch the needle on the vacuum gauge to see if the system shows signs of a leak. It shouldn't leak if the brass fittings were correctly attached to the reservoir with thread-sealing tape. However, it's not uncommon to have a small leak show up. The fix for this is simple.

Congratulations... your Project: V2 vacuum press system is complete!

If you decide to upgrade your air compressor and would like a faster and more powerful vacuum, be sure to check out the V2 Premium which is now available in an upgrade kit for the standard V2 and V2 Plus systems. Contact me for details.

Is there something that would improve this article? Misspellings, grammatical errors, or something that just doesn't make sense? Feel free to email me with any questions or suggestions about this article. I've spent countless evenings working on this project and even more time creating this article. I look forward to your comments and suggestions.

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