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Discussion Starter · #1 ·
I would like to flex my 1/8" birchply substrate after I have adhered the veneer to it.

My plan is to groove the back side of the birchply to allow it to flex more freely. It is fairly stiff as is. The grooves would have to be very shallow, I know. I will use my table saw blade for this.

Once this is done, I will then adhered my veneered board onto my box side which has a very slight curve to it. The side of the box is 11" (height) by 12" (width). The side will curve in a downward direction.

My biggest concern is this:

Does anyone see a problem in slightly flexing the substrate after the veneer has been adhered to it?

If so, then, please, gimme a hollar and get me back on track. I don't wanna mess up my first veneered box if I can help it.

Much obliged for any help that can be provided to this veneer rookie.
 

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There are variables as to whether there will be a problem. The type of veneer used...is it an all wood veneer, or a paper backed, or a peel and stick? Then, of course is what you use for an adhesive for the all wood. Test the substrate first to see which way it bends more easily without kerfing.

A slight curve may not be problematic, as the kerfs have to be deep enough and spaced accordingly to get the curve without the substrate cracking or showing flats. Why can't you veneer after?





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For a first veneer project, I think you are taking a big risk.

The veneers are thin. You are effectively wanting to stretch the veneer by flexing the substrate. You may get cracks.

I would make a mold of your curve and apply the veneer to the curved substrate.

How are you intending to apply the veneer, by clamping, vacuum, etc.

This is a video I found very interesting of the "old style" method to apply a veneer called "hammering". Turns out not the type of hammer you would expect.

The old style uses hyde glue and a flat implement to squeeze out the hide to get the effect of a "manual" vacuum on the veneer.

I think this is worth watching even if you do not use this technique.
http://woodtreks.com/learn-how-hammer-veneers-hand-tools-inlay-marquetry-hide-glue/1493/
 

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I would not use 1/8" Birch ply for that, too risky.

There is a product though, that does exactly what you want to do very well. Google 'Kerfcore".

I also prefer veneering panels flat and then doing the curves, much faster, much easier.
 
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I think you will definitely have a problem if you veneer first. The veneer, even a thin veneer will stiffen the play. When you try to bend the ply, the veneer will not want to give. It will crack. By applying the veneer first, you are essentially creating a torsion box which by nature is a design meant NOT to flex. The vener will be in tension against the ply. It is the same principle used in cold molding wood forms and in making steel I-beams. I could be wrong, but I personally would not do it.
 

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Discussion Starter · #6 ·
There are variables as to whether there will be a problem. The type of veneer used...is it an all wood veneer, or a paper backed, or a peel and stick? Then, of course is what you use for an adhesive for the all wood. Test the substrate first to see which way it bends more easily without kerfing.

A slight curve may not be problematic, as the kerfs have to be deep enough and spaced accordingly to get the curve without the substrate cracking or showing flats. Why can't you veneer after?
The curve I plan would indeed be very slight or shallow, but the birch pw I purchased is not that easy to flex which was why I thought it necessary to evenly kerf the back prior to glueing the veneer to it.

However, I'm beginning to think that this curving business is going to be a lot of work and at the end of the day will not add much - if anything, to the beauty of this jewelry box. I've learned that in life the most elegant solutions to a problem are always the simplest as well.

So - to answer your question: "Why can't you veneer after?"

I think the short answer is that it would be more problematic, but if I veneer the side(s) before I glue the carcass up (without using the 1/8" birch ply), then this would be a simpler task to accomplish. It's a matter of making matching forms to insure even pressure during glue up.

My real problem is going to be the front which will be vertically book-ended and this is going to include all drawers. I will probably begin a new thread on that later on.

Thanks for your help. It is much appreciated.
 

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Discussion Starter · #7 ·
I think you will definitely have a problem if you veneer first. The veneer, even a thin veneer will stiffen the play. When you try to bend the ply, the veneer will not want to give. It will crack. By applying the veneer first, you are essentially creating a torsion box which by nature is a design meant NOT to flex. The vener will be in tension against the ply. It is the same principle used in cold molding wood forms and in making steel I-beams. I could be wrong, but I personally would not do it.
I hear you loud and clear. I can envision the compression in the middle of the bend and the tension at the ends. Great point.

This idea has been abandoned.
 

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Discussion Starter · #8 ·
For a first veneer project, I think you are taking a big risk.

The veneers are thin. You are effectively wanting to stretch the veneer by flexing the substrate. You may get cracks.

I would make a mold of your curve and apply the veneer to the curved substrate.

How are you intending to apply the veneer, by clamping, vacuum, etc.

This is a video I found very interesting of the "old style" method to apply a veneer called "hammering". Turns out not the type of hammer you would expect.

The old style uses hyde glue and a flat implement to squeeze out the hide to get the effect of a "manual" vacuum on the veneer.

I think this is worth watching even if you do not use this technique.
http://woodtreks.com/learn-how-hammer-veneers-hand-tools-inlay-marquetry-hide-glue/1493/
OK, you guy's are smacking me around soundly and that's what I was needing.

I will forget about this idea and get moving in the right direction.

My real problem is that I have not even touched a sheet of veneer, but I have ordered several sheets to begin testing with. Veneering is most definitely one of those experiences that is only learned by doing 'hands on'.

Thanks for your help. It is much appreciated.
 

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Discussion Starter · #9 ·
I would not use 1/8" Birch ply for that, too risky.

There is a product though, that does exactly what you want to do very well. Google 'Kerfcore".

I also prefer veneering panels flat and then doing the curves, much faster, much easier.
When all of you guys are offering the same exact advise, then I'd better listen up and head in a different direction.

I will check out Kerfcore as well.

You comments and suggestions are much appreciated.
 
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