Veneering Question

[John TenEyck]

I'm well familiar with the practice of balanced veneer construction. However, I have a cabinet I'm making where it would save me a lot of time as well as materials if I could veneer only one side of my Baltic birch core. So I was thinking of drum sanding off the face veneer on one side and then gluing on my shop sawn veneer with epoxy. Epoxy would eliminate water induced bowing and the construction would be balanced again afterwards, if not exactly equal to the original. I've broken quite a few rules over the years, some even related to woodworking. Is this another I can or am I headed for woodworking jail?

John

[Mike Henderson]

I've veneered one side of Baltic birch with commercial veneer (1/42") without problems. I don't think you would have problems doing that with shop sawn (thicker) veneer but I've never done it that way.

Especially if you're going to use epoxy (non-water based glue). Most of the problems I've had with warping have been traced to using water based glue. The water caused one side of the substrate to expand and you get warping. If you finish both sides the same with a good finish I doubt if you'll have warping later.

Mike

[Philipp Jaindl]

Every single piece i have seen thats been veneered on one side only was warped so i wouldnt recommend doing it, not saying it cant be done just that i wouldnt.

Depending on how thick your Veneer is you can use thick paper on the side not seen to save cost and time though its not ideal either. If you do make your own Veneer just use some pieces with knots and defects for the other side thats the safest option since you're gonna have the same thickness veneer on both sides to cancel each others "pulling" out.

[John TenEyck]

Thanks Mike and Philipp. I should clarify that both sides will show, both the Baltic birch which will be on the inside of a shoe cubby cabinet and the outside walnut face. I could veneer over the BB with maple but then it won't match perfectly with the rest of the BB cubby components, and I don't want to put maple veneer on all of them. And I don't want to use commercial maple veneer plywood for those components either because of how thin and fragile it is.

OK, more input? Thanks.

John

[John Lanciani]

I'm well familiar with the practice of balanced veneer construction. However, I have a cabinet I'm making where it would save me a lot of time as well as materials if I could veneer only one side of my Baltic birch core. So I was thinking of drum sanding off the face veneer on one side and then gluing on my shop sawn veneer with epoxy. Epoxy would eliminate water induced bowing and the construction would be balanced again afterwards, if not exactly equal to the original. I've broken quite a few rules over the years, some even related to woodworking. Is this another I can or am I headed for woodworking jail?

John

I do it all the time, and I even use better bond pva. The only thing I do is to not sand the veneer off of the ply until the last minute, right before I need to put it in the bag. Dozens of doors, 100% success.

[Edwin Santos]

John,
Well the veneering rule hanging prominently over the bar states whatever you do to one side, you should do to the other.

However, in thinking about BB, what is it if not a stack of veneers? And the veneers are glued at cross directions to each other for further stability. So logically speaking if you were to veneer one side of something that is inherently stable, it should continue to be stable.
Of course there is a counter argument to this logic, which is that you'll notice BB always has an odd number of plies (3,5,7,9,13). So what these crafty Russians are doing is taking a center ply sandwiched by an even number of surrounding plies. This equation becomes imbalanced by adding one more ply to one side and so in theory the center of the sandwich is presented with more stress on one side than the other.

The more important thought that comes to my mind is whether the construction of your project will create additional resistance to warp as an assembly where the veneered part(s) are captured on 2, 3 or 4 sides. I suspecting it would. So being the gambler that I am, I would give it a shot, but be prompt about moving on to the construction of your carcase after the veneering step.

I think your idea to eliminate the water based glue is an important step, plus in my opinion PVA glues are more prone to "cold creep". I would put a urea resin type glue like Unibond 800 on your glue candidate list.

Not sure I gave you an answer, but hopefully some of this is helpful,
Edwin

[John TenEyck]

Thanks John and Edwin. Just to be clear, I would sand off one ply on one side, so that when I glue on the new veneer layer the finished construction will again be balanced with an equal number of plies on both side of center. As for Unibond 800, it contains water just like Weldwood PRG, only it's already in the jug of liquid you buy. Adding water to one side doesn't sound like a good idea to me so I think I'll stick with epoxy.

The veneered pieces will be sides of the two cabinets I'm making, so they will be stiffened by the top and bottom, back, and faceframe to help prevent bowing or bending. But the pieces are going to have to sit several days or even weeks before I get the cabinets built, so they need to stay flat on their own.

OK, I'm going to give this a shot on one piece. I'll post back the results after its been out of the bag a couple of days.

Thanks very much for all your input.

John

[Carlos Alvarez]

I built a bar from Wenge, zebrawood, and ply with veneers about ten years ago. It's still solid. The top is home-sawn veneer attached with contact cement. Just a big can of contact cement, applied with one of those ridged applicators, then the veneer clamped to that for a few hours. Another part has commercial veneer also applied with contact cement. I didn't veneer both sides on any piece and have not experienced any issues.

[Steve Jenkins]

I know you know this but for those that don’t you don’t want the panels lying around flat unless they are covered. Lying flat and uncovered will warp.

[Jamie Buxton]

OP, how thick is your Baltic birch? Adding an unbalanced veneer to 6 mm ply is very different from adding it to 24 mm ply.

[Scott Austin]

I just did this. Built cabinet/face frame then veenered. Used iron on, probably mistake.

All looked good till I sprayed lacquer. It bubbled up in multiple locations. Had to slit & yellow glue all defects. Then would spray & sand multiple coats. Then just hit low spots after sanding. Then more coats, sanded & rubbed out.

It actually looked good completed but was a hell of a lot of work.

What I will do next is use contact cement. Should I use solvent based only ?

Also will do 1-2 coats of dewaxed shellac before lacquer.

[Edwin Santos]

As for Unibond 800, it contains water just like Weldwood PRG, only it's already in the jug of liquid you buy. Adding water to one side doesn't sound like a good idea to me so I think I'll stick with epoxy.



John

Duh (smacks head)!

Now that I understand what you're doing, you're not really veneering in the classic sense. This is a veneer transplant operation.
Good luck, love to hear how it turns out.
Edwin

[John TenEyck]

OP, how thick is your Baltic birch? Adding an unbalanced veneer to 6 mm ply is very different from adding it to 24 mm ply.

18 mm.

I sanded off the face veneer on a 14 x 25" panel and glued on my 1/16" shop sawn walnut veneer with T-88 epoxy. We'll see what it looks like tomorrow when I take it out of the bag.

John

[Jamie Buxton]

So what do you see, John?

[John TenEyck]

I did two panels, a day apart. Both are fine so far, after 1 and 2 days out of the bag. They are going to have to sit unused now for at least a week before I get back to this project. I'll let you know how they look when I go to use them.

John

[John TenEyck]

OK, post script. I used one of the panels after 2 weeks. I just used the other one today, after 3+ weeks. Both are still as flat as when I took them out of the bag. So, veneering one side of a piece of plywood works. To recap, I sanded off the last ply on one side of the plywood panel and glued on my new veneer with epoxy. As John L. noted, it can successfully be done w/o first sanding off the last ply and with TB type glue. I wasn't that bold, but apparently the method is pretty forgiving.

John