Veneer

[Ridgeway]

I have been trying to use my enforced down time to learn some new WW skills.

In particular, I am trying to learn to cut and mount my own veneer.  

I have been trying out small pieces (3" x 5" or so), and I can get a pretty consistent 3/32" thickness on my bandsaw.  The bandsaw leaves ridges, but they are pretty consistent in depth.  I found that it is unnecessary to sand off the ridges on the side that gets mounted to the substrate (I am using plywood).  I have just been spreading the glue evenly,  then adding a sheet of wax paper and another piece of ply as a caul, plus a bunch of clamps, and the surface bond seems perfect.  Will that continue to be the case as I scale up in size, or do I need to figure a way to smooth the glue side?

Also, when using ply as a substrate, is it necessary to veneer both sides?  Does it matter how thick the ply is?

I'd love to hear some wisdom from you guys.

[jteneyck]

You definitely want to veneer both sides for any large panel.  I proved that again to myself just last week.  When I told a good friend that a panel I had veneered on just one side warped he pointed out that he rarely gets rewarded for not following the rules.  

If your bandsaw can cut veneer of consistent thickness with little variation in the depth of the ridges then there's no need to smooth them before gluing.  But if the thickness is not really consistent you won't get uniform clamping pressure if you are using rigid cauls, nor will you on the bottom side even in a vacuum bag.  I use breather mesh between the bottom veneer and caul in my vacuum bag to overcome this problem.  If you are using rigid cauls and mechanical clamping then you shoud use a flexible membrane between the veneer and caul.  1/8" silicone foam with an appropriate Durometer is a good choice.  Sorry, I can't remember what I used to use, but can look it up if needed.  

Not many folks can cut large pieces of veneer with consistent thickness top to bottom and end to end.  Deviations larger than about 0.005" usually leads to trouble.   

John

[Ridgeway]

You definitely want to veneer both sides for any large panel.  I proved that again to myself just last week.  When I told a good friend that a panel I had veneered on just one side warped he pointed out that he rarely gets rewarded for not following the rules.  

If your bandsaw can cut veneer of consistent thickness with little variation in the depth of the ridges then there's no need to smooth them before gluing.  But if the thickness is not really consistent you won't get uniform clamping pressure if you are using rigid cauls, nor will you on the bottom side even in a vacuum bag.  I use breather mesh between the bottom veneer and caul in my vacuum bag to overcome this problem.  If you are using rigid cauls and mechanical clamping then you shoud use a flexible membrane between the veneer and caul.  1/8" silicone foam with an appropriate Durometer is a good choice.  Sorry, I can't remember what I used to use, but can look it up if needed.  

Not many folks can cut large pieces of veneer with consistent thickness top to bottom and end to end.  Deviations larger than about 0.005" usually leads to trouble.   

John

Thanks -- here are some examples of what I have been fooling around with from a little piece of maple burl.

[attachment=25487][attachment=25488][attachment=25489]

The one on top is my attempt at bookmatching, and the one at the bottom is an example of one of the pieces off the saw before mounting and sanding.

[SteveS]

For one side veneering it is a question of dimensional ratios. The larger the panel the thicker it has to be to resist warping. I've done lots of one sided veneering, but only on small or narrow panels. Since plywood is somewhat isotropic, you can get away with a bit more than solid wood. Short answer is if you don't know what you can get away with, it's best to do both sides.

[Mr Eddie]

I have been trying to use my enforced down time to learn some new WW skills.

In particular, I am trying to learn to cut and mount my own veneer.  

I have been trying out small pieces (3" x 5" or so), and I can get a pretty consistent 3/32" thickness on my bandsaw.  The bandsaw leaves ridges, but they are pretty consistent in depth.  I found that it is unnecessary to sand off the ridges on the side that gets mounted to the substrate (I am using plywood).  I have just been spreading the glue evenly,  then adding a sheet of wax paper and another piece of ply as a caul, plus a bunch of clamps, and the surface bond seems perfect.  Will that continue to be the case as I scale up in size, or do I need to figure a way to smooth the glue side?

Also, when using ply as a substrate, is it necessary to veneer both sides?  Does it matter how thick the ply is?

I'd love to hear some wisdom from you guys.

I have been able to cut thin veneers on an older 14" Delta and get a pretty smooth surface.  I've found that starting the cut slowly so as to engage the blade evenly is important.  I was able to eliminate most of the ridges by feeding at a steady rate and never stopping during the cut.  And of course a sharp blade is a given.  I would try to get the glue side of your veneer as smooth as you can.  As you move to larger panels the telegraphing of the ridges is going to be more apparent.  If you have a jointer you could joint between cuts so you always have one smooth side.  Glue the smooth side down and use a ROS to clean up the rough side.  I would always veneer both sides.  You can buy backer veneer very cheaply.  Here's a couple of veneer sites for those times you don't want to cut your own or want something exotci:

www.CertainlyWood.com
www.VeneerSupplies.com
www.dyed-veneer.com

Have fun!
Lonnie