How to edge glue 3/16" solid wood veneer?

[Ronald Kot]

I am looking for advice just one specific step of a veneer project, namely, how to glue the edges to make up a larger veneer sheet. I have never done this before.

The project is to veneer plywood that will make up 2 cabinet sides and 2 drawer fronts.

I am cutting 3/16" thick slices from solid wood (white oak, rift sawn) using these steps:
- thickness plane the blank before each bandsaw pass,
- bandsaw 3/16" thick slices. The resulting "leaves" are smooth on one side, bandsaw blade marks on the other.

Size of the leaves are about 4" x 18". I need to edge glue together 5 of these 3/16 x 4 x 18 leaves to make up the larger veneer sheet.

Each glued up veneer sheet will overlap the substrate (3/4) Baltic birch, by 1/4" all around. I will veneering both sides of the substrate.

At a local woodshop, the 3/16" veneer panel will go through a thickness sander to get it to 1/8", and the glue applied, overlay the substrate, and into a cold press.

Questions:

1. What type of glue for these 3/16 thin edges? Titebond 2, not 3? Or?

2. How to apply the glue?


3. What type of tape? How frequently to tape?


4. Tape both top and bottom of assembled veneer sheet?

5 Do I need to clamp to apply edge pressure to these thin glue joints? If so, what kind of clamping setup?

Thanks for any help!

[Peter Quinn]

My approach? Joint the meeting edges well, blue painters tape on the smooth side perpendicular to the wood, standoffs perpendicular to the wood grain from under neath every 8" or so, use tite bond II or III with WO s the color of the glue line is similar. I would either use cauls above clamped to the standoffs to keep things flat or put some weight on it, like a couple of bricks wrapped in plastic cling wrap. I'd use light clamping pressure. Just enough to get squeeze along the whole glue line. You may want to glue up two pieces and three, let these set, then glue these two smaller panels together. This way you have less total glue lines to deal with. Glue applicator? I'd use a fine tipped squeeze bottle and a little swipe of my finger. Keep a damp towel handy to clean teh finger so you don't get glue everywhere.

[Chris Fournier]

Search the web for "gluing up acoustic guitar tops" and you'll see several good techniques to achieve what you're after.

A word of caution regarding your shop made veneer: the thicker your "veneer" the more it behaves like solid wood. I have found that 0.125" veneer is prone to considerable movement and can really be a problem if you don't lay it up in a manner that tries to restrict the inevitable wood movement. I personally would go much thinner on your project especially because the components are not table surfaces but sides.

I like to make my shop sawn veneer between 0.030" to 0.625" thick for most of my projects. This is thin enough to not have to worry about the aforementioned problems but thick enough to be able to use handplanes and not have to worry about durability on table surfaces.

To avoid the difficulty of curling your veneer during the glue up apply the glue to the substrate. PVA will work just fine and you could even consider particle board or MDF as the substrate. In my experience they both stay flatter than plywood.

Good luck!

[Jamie Buxton]

Even with bandsaw veneer, I don't edgeglue it. I just tape it together with veneer tape (on the show side) and glue it to the substrate. My theory is that the most important bond is the one from the veneer to the substrate. That's the one that I want to be very secure. If I were to edgeglue the veneer, and misalign the leaves a bit, there might be a void under the veneer near that misalignment. If I don't edgeglue the veneer, the press (I use a vacuum press) can squeeze everything down nice and tight.

I too would be concerned about your proposed veneer thickness. 3/16" is enough solid lumber that its attempt to move can pull the substrate around. Thinner veneer will let the substrate's behavior dominate. At the College of the Redwoods (Krenov's program), they've been doing bandsawn veneer intensively for decades. They say that 3/32" is okay. I generally saw at .1", and expect to net .08" or so.

[Robert Reece]

Are you applying the same veneer to both sides? If not, I agree 3/16" is a little thick.

[Ted Wong]

As others have mentioned 3/16" is too thick for veneer. Try to stay around 1/16" maximum.

[Eiji Fuller]

I agree. Go thin and don't edge glue.

[Ronald Kot]

Thank you all for addressing my questions. The idea of not to edge glue it at all seems quite good. And if I can I will go that route, and set my final thickness target to the what has been successful in the Krenov's Program - bandsawn veneer at - 3/32" (.09375) - so that is what I will shoot for. Understanding that is the final thickness on the plywood.

But if I ever do edge glue thin material, I thank Crhis for his tip - searching on google I found this link which explains a very slick method:
http://www.youtube.com/watch?v=_W3EW7gqGVM

NO EDGE GLUE
Bandsaw cut Veneer at 1/8" thick, and later down to (kernov) thicknes target of 3/32" by final sanding on a thickness sander.

I did not mention the last step of thickness sanding in my initial description….I did have that in mind when I said I would bandsaw veneer initially at 3/16".

But I do wonder if not doing the edge glue step first is a problem, as a taped surface is not even.

I assume the tape must go across to tension the unglued edges together. I cant completely cover the whole surface with tape so some areas will have tape, others will not. What will the extremely powerful hydraulic press do with the tape thickness….press it into the wood? The tape I was intending to use is thin….its 3m/Scotch blue 60 day tape, which is about .005 thou thick. So then I guess any depressions would come out in the final sanding.

If I used a thick tape, and/or if there was some kind of problem with unevenness of pressure using any tape, then maybe that is why the shop suggested I edge glue in the first place…I have to check on this.

They did say with edge gluing I would get voids in my edge gluing. No good as pressing would then crack the wood at the voids. Their solution is to thickness sand each edge glued veneer sheet at their shop before. Then after pressing, another thickness sanding to finish each veneered piece to the target thickness.

Taking this approach, I have to add thickness for 2 thickness sandings to my final target thickness of 3/32. What depth should I allow for a thickness sanding machine?

Taking 1/32 for each thickness sanding pass as an example:
Final thickness target = 3/32, and 2/32 for the TWO sandings, then bandsawn veneer thickness would be 5//32. If I add 1/32 just to be safe I am back to bandsawing thicknesses of 6/32 or 3/16 as I first described. Thickness sanding would take it to the final, suggested at around 3/32. If the thickness sander minimum is greater, I have to add more thickness to my initial cut veneer off the bandsaw.

2. How to apply the glue? Just on the plywood, so only 1 side gets glue?

Thanks again,
Ron

[Jamie Buxton]

Don't use masking tape to tape the veneer leaves together. The pressure of the press really squeezes the adhesive into the wood, and it is a terrific bother to remove. Instead, use standard veneer tape. This is a thin paper tape with a water-activated adhesive. For instance -- http://www.veneersupplies.com/products/Veneer-Joint-Tape---No-Hole-Maximum-Strength-Fast-Tack.html . I like the no-holes version because it is stronger. I tape the entire length of each joint, on the show face.

[Ronald Kot]

Jamie,
You said before that "I generally saw at .1", and expect to net .08" or so." How are you sanding off the last .02"?
Can a thickness sander go that fine? I am wondering how much thickness to leave for a final thickness sander sanding pass.

About the veneer tape, I will try to find some. I have been told by those that vacuum press, that the 60 day blue 3M tape I was going to use works very well. Comes off ok after pressing. But I dont know if the hydraulic press presses harder than a vacuum press. I will have to check. The veneer tape I see shrinks to assist pulling the unglued leaves together at the seams, so that is better. thanks!

[Jamie Buxton]

Jamie,
You said before that "I generally saw at .1", and expect to net .08" or so." How are you sanding off the last .02"?
Can a thickness sander go that fine? I am wondering how much thickness to leave for a final thickness sander sanding pass.

About the veneer tape, I will try to find some. I have been told by those that vacuum press, that the 60 day blue 3M tape I was going to use works very well. Comes off ok after pressing. But I dont know if the hydraulic press presses harder than a vacuum press. I will have to check. The veneer tape I see shrinks to assist pulling the unglued leaves together at the seams, so that is better. thanks!

I saw at .1" or so, and glue down the result. My bandsaw (a LT16HD with a Lenox Woodmaster CT carbide-tipped blade) leaves a surface good enough to glue down. After the veneer is glued to the substrate, I clean up the exposed face. If the pieces are less than 12" wide, they go through the thickness planer. If they're wider, I tackle them with the random orbit sander.

My experience with masking tape in a vacuum press is bad. The adhesive is semi-liquid, and the press' pressure squeezes it into the pores of the wood. It does not peel off the wood cleanly, like it does in normal usage. The adhesive gums up a scraper or a sander. Veneer tape works much better. It can be removed with a scraper or a sander.

[Ted Wong]

Ron,
I am an alumni from the CR Fine Woodworking program that James Krenov help founded. During my time at the school there was a lot of veneering going on using shop sawn veneers you describe. How thick you saw the veneers has to do with your confidence level and the precision of your equipment and accuracy of your setup. If you have a smooth running bandsaw that can cut through 5" or more of wood without bogging down, blade deflection or wandering and it can leave a smooth uniform surface then I'd shoot for 1/8" - 3/32" off the saw depending on your confidence level. Bear in mind if you are trying to do a book match or any sort of grain matching on the veneer thicker cuts at the saw and heavy stock removel afterwards (1/32" or more) will have a tendency to reduce the grain matching.
At the school students always edge glued their veneers. If the veneer tended towards the thicker end of the spectrum (3/32") we would use a system of wedges, stops and a torsion box to glue up the veneer sheet. At the thinner end (1/16" or less) we would use blue masking tape as you describe. What type of glue you use depends on the wood species and trial and error. I've always used some type of PVA glue. Sometimes it is white, yellow or brown depending on what I have on hand and what works well.
Hope this helps you in your quest.

[Ronald Kot]

I saw at .1" or so, and glue down the result.

My bandsaw (a LT16HD with a Lenox Woodmaster CT carbide-tipped blade) leaves a surface good enough to glue down. After the veneer is glued to the substrate, I clean up the exposed face. If the pieces are less than 12" wide, they go through the thickness planer. If they're wider, I tackle them with the random orbit sander.

My experience with masking tape in a vacuum press is bad. The adhesive is semi-liquid, and the press' pressure squeezes it into the pores of the wood. It does not peel off the wood cleanly, like it does in normal usage. The adhesive gums up a scraper or a sander. Veneer tape works much better. It can be removed with a scraper or a sander.

Jamie,

Can you recommend a good source for the Lennox Woodmaster CT bandsaw blade? In Canada? or Usa, if that is where you are. I have the Laguna LT16.

Point taken on the veneer tape. But my blue 60 day 3M tape is not ordinary masking tape, it was recommended for vacuum press work, so it may be ok, but I think you are right,,,,the veneer tape would be best.

My thickness planer is 13", my piece width is 12 7/8 and 16", so looks like I have no option for using my thickness planer on this project, but I will try this method for narrow projects. Otherwise, random orbit sander, or thickness planer. Thanks for the tip!

[David Woodruff]

Search the web for "gluing up acoustic guitar tops" and you'll see several good techniques to achieve what you're after.

A word of caution regarding your shop made veneer: the thicker your "veneer" the more it behaves like solid wood. I have found that 0.125" veneer is prone to considerable movement and can really be a problem if you don't lay it up in a manner that tries to restrict the inevitable wood movement. I personally would go much thinner on your project especially because the components are not table surfaces but sides.

I like to make my shop sawn veneer between 0.030" to 0.625" thick for most of my projects. This is thin enough to not have to worry about the aforementioned problems but thick enough to be able to use handplanes and not have to worry about durability on table surfaces.

To avoid the difficulty of curling your veneer during the glue up apply the glue to the substrate. PVA will work just fine and you could even consider particle board or MDF as the substrate. In my experience they both stay flatter than plywood.

Good luck!
did you mean .0625"

[Al Navas]

Typically, I resaw veneer to 1/8-inch thick, pass through the drum sander to reduce to 1/16-inch or so, then glue using the process below, and finally to the veneer press with Unibond 800.

I use (veneer) correction: blue tape strips on the back, to hold together the two pieces of veneer tightly, then open open up the seam by folding back the tape, apply Titebond II, close, and apply "pressure" by using boards, bricks, whatever is at hand:

Glue line:

http://sandal-woodsblog.com/wp-content/uploads/2008/02/1-glueline.png


Bricks as clamps:

http://sandal-woodsblog.com/wp-content/uploads/2008/02/1-brickclamps.png

Results - spalted maple veneers on MDF substrate - the seam is invisible:

http://sandal-woodsblog.com/wp-content/uploads/2008/02/1-mapleside.png

I then remove all boards and bricks, and use a scraper to remove the glue. It works great!

Al

[Ronald Kot]

Jamie, about veneer tape
you said
"My experience with masking tape in a vacuum press is bad. The adhesive is semi-liquid, and the press' pressure squeezes it into the pores of the wood. It does not peel off the wood cleanly, like it does in normal usage. The adhesive gums up a scraper or a sander. Veneer tape works much better. It can be removed with a scraper or a sander."

I just saw the blue 3m tape i am considering using here:
Joe Woodworker
http://www.veneersupplies.com/categories/Veneering__Supplies/Tools__%26__Supplies/

where they say about it:
For complicated and fussy veneer seams, you can't beat this 3M painters tape. I use this 3/4" wide clean release tape to hold the underside of two veneers together while I prepare the regular veneer tape for the face side. After the brown tape starts to set, I remove the blue tape and allow the veneers to dry before placing it in the vacuum press.
While it is undeniably expensive, 60 yards (one roll) goes a long, long way. You can also find this tape in the paint aisle of your local hardware store.


They do say

"the blue tape goes on the back of the veneer."
and then they put regular tape on the front. The back side is defined as the side you want to glue to the substrate.



Whole process discussed here:
http://www.joewoodworker.com/veneering/veneertaping.htm


What I realize reading this, is that they DO NOT edge glue at all. At least they never mention it. What they do is blue tape on glue side; veneer tape on top side, moisten and let it pull pieces together; remove blue tape from underneath; glue on substrate; veneer on top and press. Ahhhh, so thats what blue tape is for!


This is an alternate method to the u tube video that I posted in my 2nd post above, and so much easier.

[Ronald Kot]

Ron,

......................At the school students always edge glued their veneers. If the veneer tended towards the thicker end of the spectrum (3/32") we would use a system of wedges, stops and a torsion box to glue up the veneer sheet. At the thinner end (1/16" or less) we would use blue masking tape as you describe.

Ted, what is the purpose of edge gluing?

What is the down side of not edge gluing if one follows the procedure here where I cant see that they edge glue at all:
http://www.joewoodworker.com/veneering/veneertaping.htm

I would think as someone else observed that if the tape holds the pieces together ok, then once pressed the glue on the flat will hold the edges together better than the edge glue ever would???

To edge glue or not to edge glue....has become the central question for me. And here I started this thread akking how to edge glue, now It seems unnecessary and for me hard to do as I do not have the a torsion box to keep the glue up flat to avoid voids....problematic.

Thanks for your perspective!

[Al Navas]

You may want to read the David Marks veneer page (http://www.djmarks.com/stories/djm/Working_with_Veneers_46888.asp). It applies to shop-sawn veneers.

I believe that using veneer tape only, applies to the commercial veneers that are simply too thin to edge glue - the joewoodworker page shows commercial veneers, not shop-sawn veneers. As I showed in my earlier post, it is possible and desirable to edge glue shop-sawn veneers, as these are at least 2X and up to 3X thicker than commercial veneers.


Al

[Chris Padilla]

Check out my Tansu (http://www.sawmillcreek.org/showthread.php?t=92396) thread.

I shop cut 3/32" walnut veneers using both my Lenox Trimaster and my Lenox Diemaster2 blades. I do have a Lenox Woodmaster CT but I did not like it at all for cutting veneers as I felt it left too rough a surface. I see Jamie has a different experience with his Lenox Woodmaster CT.

I then fiddled with a craigslist-found Delta 18/36 drum sander for an entire Saturday to dial it in and it produced wonderful 1/16" sanded veneers. Sanding ~20 sheets of veneer will go down in my woodworking history as probably the most mind-numbing process I've ever done but the results were nothing short of fantastic!

If you read my thread, I wrestled a bit with the edge-gluing. After a couple trials of NOT edge-gluing, I went this route. I used a waterless tape that veneersupplies.com carries as well as their Better Bonds glue. It dries very hard...hard enough to slice open careless hands and fingers!!

The KEY is edge-jointing to get a nearly invisible line. There are various methods to jointing veneers to get a good, tight joint. I made a carrier sled slightly longer than my veneers and clamped the veneers between it and ran the whole thing over my jointer.

Then I lightly clamped the veneers together and used bricks and general weight to keep things from bowing up as I veneer-taped the joints. I was rewarded with very nice, tight joints after pressing the veneers in a vacuum bag. Often, the veneer glue I was using would get sucked up through the joint but not always. I looked at that as a sign that I didn't get them tight enough or the tape slipped or I didn't joint them well enough BUT, the joint looked great. I used a chocolate-colored glue so it blended well with the walnut.

[Ted Wong]

Ron whenever I use tape I always use 3m blue tape. Have never had a problem with residue or pulling out fiber. I have used other masking tapes and have had the problems described. I'm not a huge fan of veneer tape unless I'm doing marquetry, just feel it's a bit tedious for gluing up veneer leaves. Using any old tape on commercial veneer (1/40" or less) can be problematic but on shop sawn veneers you have the additional thickness that allows you to remedy any problems with cheap tape.

[Ted Wong]

I like edge gluing my veneers because for me its another layer of protection against the joint opening up should there be differential movement between the veneer and substrate occur. At the same time I say that with the caveat that wood does what it wants to. And I have had veneered surfaces that I meticulously edge glued prior to laminating to the substrate eventually open up (I used lumber core for substrate). Maybe on a flat surface it doesn't matter so much whether you glue the joints first, I can't say with certainty whether it is better or not, its just one of those things I do out of habit because I was taught that way and have been too lazy to experiment other methods. On the other hand I've veneered a lot of curved panels and in those cases I think edge gluing is a requisite to maintain tight joints.

[Al Navas]

...To edge glue or not to edge glue....has become the central question for me...
Just following up, Ronald. Have you had a chance to it out, with and without edge-gluing? Just wondering - no pressure... :cool:

Al

[Ronald Kot]

to edge glue or not to....I will. ive cut my veneer to 3/16 thickness. Each flitch is bandsaw rough on one side, jointer planed smooth on the other. I'll edge glue up the veneer panels, glue those to substrate smooth side down, press, then thickness sand off 1/16 to remove the bandsaw marks and get the final veneer thickness down to 2/16, which is .125". Or maybe a little slightly thinner, around .1 for stability.

Will be interesting to see how the edge gluing goes. I need to make up a flat surface to do the glue up on, so Im thinking of using 1" OR 3/4 MDF. I should really build a torsion box, one the right size for a vacuum press I hope to get later sometime. Then this projects supports a later project down the road.

[Al Navas]

... I should really build a torsion box, one the right size for a vacuum press I hope to get later sometime. Then this projects supports a later project down the road.
Ronald,

Good! I wish you success - I believe it will work great!

I don't believe you need a torsion box to press veneers with a vacuum press. All I use is an MDF platen, with grooves that crisscross to allow the exit of air from the bag as you turn on the pump. The platen goes on the bottom, with the grooves facing the project; the project lays on the platen; and the whole thing is topped off an MDF top caul, to distribute the pressure evenly - I now make the bottom platen closer and slightly larger than the project (this one was too large for the project I was gluing up):

http://sandal-woodsblog.com/wp-content/uploads/2008/02/1-firstpressrun1.png

I cover the entire "sandwich" with an electric blanket, and also use an outdoor "thermometer" to ensure I can keep it all above 70°F under the blanket. It was late February and still cold in NW Missouri - it is much cheaper to run the blanket than to keep the entire shop above 70°F :) when it is -10°F outside.

After success with the veneer edge-to-edge glue-up, you want to remove the blue tape from the back of the veneers, as you don't want those tape strips when you glue the veneer to the substrate.

Al