JoeWoodworker
JoeWoodworker Veneer
The Official Website of this Non-Professional Woodworker ™

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
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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)
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
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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
Copper Veneer FAQ
Downloads (PDF's)

VeneerSupplies.com

Vacuum Veneering - Tips, Tricks, and More

The Vacuum Bag Closure

The bag closure will be used to close the open end of the bag after you have inserted the veneer, substrate, and platens. Getting a good seal is not difficult. Read more about closures below to see which is best for you.

Method 1: Tube & Sleeve or C-Channel Closure (Commercial)

This type is the most common closure system sold with vacuum bags. VeneerSupplies.com has this type of vacuum bag closure in two lengths. Simply roll the bag end over the tube. Then snap the C-channel over the bag starting from one side and working towards the opposite side. To ensure a perfect seal, be certain that the entire bag opening is secured by the closure and that there are no heavily wrinkles in the bag material.

For additional clamping strength, you can attach spring clamps over the C-channel. This is not necessary under normal conditions but it will provide a better seal if the bag is heavily worn. For the ultimate gripping strength, the bag may be rolled over the tube twice before the C-channel is attached. I do not recommend more than a double roll over the tube due to the difficulty of removing the closure under such clamping pressure.

To remove the closure, pull the C-channel off of the PVC tube starting at one end and work toward to the opposite side until the closure is released.

There is one thing to note about this type of closure. It is very difficult to get a good seal if you are using a shop-made vacuum bag in which there is an overlap of the bag material on the top or bottom of the opening. If you have built a bag and your seams are not at the edges of the bag, it's best to use method 3 below.


Method 2: Tube & Sleeve or C-Channel Closure (Home-Made)
Suggested by Dan S. of Niskayuna, New York

I bought a piece of closet rod stock - 1 1/8" round slightly longer than my bag (5' in my case - $0.75/ft). I bought a piece of sch 40 1 1/4 ID PVC pipe -$0.37/ft (SCH40 is important because it is truely 1 1/4 ID). I ripped a slot in the pipe so what remains is slightly more than 1/2 way around - just enough so I have to apply a little pressure to snap it around the closet rod. Now I wrap the bag opening around the rod, snap the pipe over it and I have a near perfect seal. My pump cycles no more than once every 15 min and then for only about 30 sec. By the way - my wife suggested a shower rod cover snapped over the closet rod (bought at Bed Bath & Beyond for $1.30), that worked about as well as the original wood clap closure believe it or not - but I knew I could do better so I tried the pipe.


Method 3: DIY Dowel Closure

Find a hardwood board that is 5" wide, ¾" thick, and 30" long (or 3" longer than your bag's width) and rip it in half. Now hold the two pieces together (as if you were going to glue the ripped edge back together). See if there is a slight bow. Sometimes wood will do this and if it does, this time it will be an advantage. If not, don't worry.

If there is a bow, flip the boards around until you are looking at a gap in the middle when they are held together and draw an arrow on each board facing away from the side that has the gap. 

Set up your router (preferably router table) with a " core box bit and raise the bit 1/4" high. Run both boards across this setup with the arrows pointing down (if you are using the router table). Glue a " dowel into one of the boards as shown above. The two boards will now mate together nicely. Allow the dowel to dry before continuing.

Assemble the mated boards as shown in the picture to the right. On the left and right side of the two boards, drill a 3/8" diameter hole (about 1" in from the edges) from the top and into the bottom board.

 

 

 

Take the two boards apart and enlarge one hole on opposite board ends with a 7/16" bit.

 

 

 

 


Glue a 3/8" diameter dowel in the 3/8" holes allowing it to protrude by an inch or two at the top.

 

 

 

 

The clamping jig will now slide-lock together and make it easier to assemble the bag clamps on the vacuum bag.

 

This is your bag end closure. I prefer to use standard wood clamps starting at one end. Then place another clamp at the opposite end. Just before tightening this second clamp, use your index finger to pull the vinyl bag away from the first clamp. This keeps the vinyl flat under the bag closure.

Then place clamps along the length of the closure every 6 to 8 inches. Be sure to place a clamp over the seam overlap on the vacuum bag. This is where most leaks occur.

From Farrell Boris of Old Westbury, New York:

My bag clamp has "pockets" in it spaced evenly apart to accept the bar clamp. This allows the clamp to stay seated when tightening without the "wander" and also ensures even spacing between clamps. I used the appropriate diameter spade bit in my drill press and made each pocket deep enough to seat the clamp pad flush with the top of the bag clamp.

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The Vac FAQ
Heat Lock Veneer Glue