Bookmatching veneer question

[Nick Decker]

OK, so I finally got a decent bandsaw, and have been able to slice some nice consistent 1/16th veneer with it. (This in itself is pretty cool for a hack like me!) I'm itchin' to try bookmatching a couple of slices for a box top I'm making. Is this a job for veneer tape, to keep the butted pieces from creeping apart when I clamp them? I've done quite a few single pieces before, just using a bunch of clamps to clamp plywood platens together, but that's about as far as I've taken it. Any hints appreciated!

[Jamie Buxton]

When I saw veneer, I use veneer tape to hold the pieces together when they go into the press.

I generally rejoint the edges after I resaw, because the sawing leaves little splinters and tears at the exit.

[John TenEyck]

I use veneer tape to hold my jointed, shop sawn veneer pieces tight together. Then I go one step further. I crack those joints open enough to run a bead of Titebond in the joint, then fold it shut again and wipe off the excess. Once the glue dries you have a very stable panel, with no danger of a joint opening or glue squeezing through when you glue it to your substrate.

John

[Nick Decker]

Thanks, guys.

[Jamie Buxton]

I use veneer tape to hold my jointed, shop sawn veneer pieces tight together. Then I go one step further. I crack those joints open enough to run a bead of Titebond in the joint, then fold it shut again and wipe off the excess. Once the glue dries you have a very stable panel, with no danger of a joint opening or glue squeezing through when you glue it to your substrate.

John

I don't glue the leaves together. My concern is that my veneer leaves aren't all the same thickness everywhere. (I'm making furniture-sized panels, so there's long runs with tall stock, and the bandsaw blade just drifts around some.) If I were to tape the leaves together on the top face, and glue them together, there would be air gaps under the spots where the veneer is thin. I'd rather have all the veneer glue down to the substrate with the thinnest possible glue line. Then I solve the unequal-thickness problem by scraping the top surface flat.

[Kevin Jenness]

I do as John suggests, but I use blue tape. I find just using veneer tape without glue is a bit weak with thick veneers that want to move a bit, and I like the insurance against joints opening up and the ease of handling a glued assembly. I run the sawn veneer through a wide belt so that I am gluing up evenly thick layers. If I did not I would have to use some type of soft caul to absorb the variations and get a reliable bond in the press.

[John TenEyck]

Jamie, you are correct that you don't want any air pockets under the veneer which might happen if the veneer is not of constant thickness. But that's one reason drum sanders were developed, and I run all my veneer through my drum sander, on both sides, so they all have the same thickness. Scraping the top surface is OK for a few pieces, but for a large project the drum or wide belt sander is a much more efficient solution.

On the subject of avoiding air pockets, I now use a piece of 1/8" sponge rubber under the bottom panel, and between panels if I'm doing more than one, when it goes in the vacuum bag. The rubber has a compression of 25% at 15 psi, IIRC, which means it can compress enough to make sure there is uniform pressure on the veneer regardless of variations in thickness. You may want to use something like this if you aren't already. It's not needed for the veneer layer being pressed by the bag, but it is for veneer trapped between a bottom caul and substrate, or veneer layers in the middle when pressing multiple parts on top of each other. I had a couple of joints lift even before I started edge gluing the veneer together because of slight differences in thickness. In fact, that's one reason I started edge gluing, but adding the sponge rubber completely eliminates the problem.

John

[Mike Henderson]

The advantage of veneer tape over blue tape is that the veneer tape shrinks a bit when it dries, pulling the joint tighter and maybe eliminating a gap. You can get veneer tape in different weights which have different strengths. I tend to use a very thin veneer tape but I have some heavier duty tape for when I need it.

But for sawn veneer, I do like John and glue them together. If you prepare the veneer well, they will be of equal thickness and the backs will be smooth so gluing them together is about the same as having a larger piece of veneer.

For pressing, you can use carpet padding between the work and your caul (with plastic between the work and the padding) to distribute the pressure over the variations in the thickness of the veneer.

Mike

[Robert Engel]

If you pull on the painter tape as you're stretching across the joint, you accomplish the same thing.

If pressing, I use padding. Shelf liner works but don't use the mesh type the pattern will transfer to the veneer (how do i know that.....?:-)

I tried the pva glue/ hot iron method on some drawer fronts and I really like this technique.

[Nick Decker]

I haven't cut the veneer yet, but I think I'll try John's method of taping, folding open, then gluing along the seam. If I cut the veneer at a little under 1/8" that should leave me a decent edge to glue. Wipe excess, let dry, then apply it to the substrate. I do have a drum sander (10-20), so I can then even everything up with that. Sound about right?

I'm expecting some new blades from Spectrum in a few days, which I want to experiment with a bit to figure out what works best with my saw. Really appreciate the comments, guys.

[John TenEyck]

Nick, I edge glue shop sawn veneer at only 0.050", and have no doubt it would be possible on even thinner material. Shop sawn veneer is an entirely different animal than commercial sliced veneer and, to my way of thinking, far superior. It has none of the inherent defects of sliced veneer so you can use whatever side looks best to you, it's far easier to handle, you can edge joint it just like solid stock, you can edge glue it as discussed, and since it's generally thicker than commercial veneer you can actually sand it w/o undo worry of cutting through it.

Most of the veneer I make I saw at around 0.090". My bandsaw (Grizzly G0636X) and blade (1" x 1.3 tpi Woodmaster CT) combination is good enough that I don't have to rejoint or plane the board between cuts. I start with 4 square stock and then cut one piece after another from one face. The offcut from the last cut will either be too thin to use or extra thick. The too thin ones are lost, but the extra thick ones go into the good pile for final thicknessing through the drum sander. If I cut them at 0.090" I am usually able to sand both sides two or three times and end up at 0.060 - 0.065".

John

An important note. Do NOT use cold set glue with shop sawn veneer, at least not Better Bond. I had two projects where the seams curled open after a few months. An inquiry to Joe Woodworker revealed that that product is not recommended for shop sawn veneer. I believe that tidbit of info. is now listed on his website with respect to that glue; perhaps my inquiry led to that because it was not when I used it. I've pretty much settled on Weldwood Plastic Resin Glue for gluing shop sawn veneer, occasionally epoxy when I'm veneering the side of a Melamine panel. Costs a little more and takes a little longer to cure, but I've never had an issue with either. And of course for outdoor use they are a must.

John

[Nick Decker]

John,

So I guess Titebond II is out for shop sawn veneer? Rats. I'm pretty comfortable with that stuff.

Edit: Keep in mind, I'm only veneering an area about 6x12" and it doesn't need to be water resistant.

[John Lanciani]

John,

So I guess Titebond II is out for shop sawn veneer? Rats. I'm pretty comfortable with that stuff.

Edit: Keep in mind, I'm only veneering an area about 6x12" and it doesn't need to be water resistant.

Ive done several hundred sq.ft. Of 1/16" shop sawn veneer over the past 10 years with Lee Valley's GF2002 pva glue which is similar in concept to the better bond pva and I have had no failures to date. Not disputing JT's experience at all, just another data point.

[Chris Padilla]

An important note. Do NOT use cold set glue with shop sawn veneer, at least not Better Bond. I had two projects where the seams curled open after a few months. An inquiry to Joe Woodworker revealed that that product is not recommended for shop sawn veneer. I believe that tidbit of info. is now listed on his website with respect to that glue; perhaps my inquiry led to that because it was not when I used it. I've pretty much settled on Weldwood Plastic Resin Glue for gluing shop sawn veneer, occasionally epoxy when I'm veneering the side of a Melamine panel. Costs a little more and takes a little longer to cure, but I've never had an issue with either. And of course for outdoor use they are a must.

John

I asked Joe about that and he said that it was because shop-sawn veneers tend to much thicker than commercial-sawn veneers and therefore can still act like much thicker hardwood and move around due to moisture changes.

He didn't have a specific number as to how thick is too thick as it depended upon the species of wood.

Anyway, for what it is worth to the subject, I shop-sawed black walnut veneers and drum-sanded them down to 1/16" dead-nuts. That is 0.0625" in decimal form. I bookmatched the whole tansu (http://www.sawmillcreek.org/showthread.php?92396) with this veneer and Better Bonds and completed the project in 2009. It was then sealed with shellac. Still perfect today 8 years later in our living room.

BTW, I do not glue the edges together for bookmatching. I just pull 'em nice 'n snug and use veneer tape. Sometimes I'll use a good old Bessey clamp to snug 'em up.

You'll need a good method to joint the edges of your veneer. I built a clamping device from wood that will allow me to clamp the two piece of veneer with just a frog-hair sticking out and then I run the whole thing across the jointer jointing the veneer and my clamping device. If the veneer is small enough, a 'stick' of S4S hardwood (2" x 2" by whatever length) with some sandpaper glued to two adjacent sides works nicely to joint as well. Clamp the two veneer pieces down tightly with just a frog-hair sticking out and run the stick across it lightly sanding/jointing both pieces.

[Mike Henderson]

In general, I've had problems with that cold press glue. I use PVA (Elmer's GlueAll white glue or Titebond), or Urea Formaldehyde. I've glued a lot of veneer with Elmer's.

Mike

[Chris Padilla]

Ive done several hundred sq.ft. Of 1/16" shop sawn veneer over the past 10 years with Lee Valley's GF2002 pva glue which is similar in concept to the better bond pva and I have had no failures to date. Not disputing JT's experience at all, just another data point.
Well there is a second example of 1/16" shop-sawn veneer staying put. What species of wood, John?

IMO, wood > 1/16" is NOT veneer and will act more like regular hardwood in terms of movement.

[John Lanciani]

Well there is a second example of 1/16" shop-sawn veneer staying put. What species of wood, John?

IMO, wood > 1/16" is NOT veneer and will act more like regular hardwood in terms of movement.

QS hard maple, quilted soft maple and QS sycamore for the most part. All fairly stable woods, book matched onto panels up to 24" wide for cabinet doors and drawer fronts.

[John TenEyck]

The two projects where I used Better Bond were with white oak, 1/16" thick, on a Baltic birch substrate and the joints were not pre-glued. The Better Bond directions say you can pull the glued up panel out of the vacuum bag after only an hour. I made a test panel following those directions; all looked good until the next morning. All the joints were curled open something awful. I should have just gone back to PRG right then but I was hoping the Better Bond would allow a faster cycle time through the shop. So I made another test panel and left it in the bag for 4 hours. It looked good, and continued to look good for a week so I went ahead with the two projects I had, both with rift sawn white oak. Four to six months later I got a call from my client saying the small table tops I had made "looked funny". So I went to look at them. Sure enough, the joints were starting to curl up. I replaced them, offered my apologies, and concluded Better Bond has no place with shop sawn veneer. Since then I've started gluing the seams before gluing the veneer to the substrate. I don't know if that would have eliminated the seam curling problem with the Better Bond glue. Maybe, but I'm not going back to find out.

The good news is I've been able to reduce the cycle time with PRG by putting a heating blanket under my vacuum bag and another over the top. I'm usually able to hit the right temp. to pull the panel in less than 6 hours, which allows two cycles per day.

John

[Nick Decker]

I tried Better Bond on a couple of small projects, box lids, but using commercial veneer. The instructions said to leave it clamped NO MORE THAN an hour. I thought that odd, and emailed Joe about it. He said that leaving it clamped longer than that could cause mold. New one on me.

The annoying thing was that the dark solids (ground pecan shells, IIRC) sunk to the bottom of the container, and the thickness made it next to impossible to shake them back into the mixture. Titebond had always worked well for me, so I went back to that.

[Chris Padilla]

I used the dark BB for the walnut and the lighter one for some maple. It is interesting that some of us have done well with it and others aren't going to touch it again. I dunno what's up. Bad batches? Bad wood? Operator error? ???