using veneer as spacer material
I've seen plenty of knives on here with spacers made from metal, horn, wood, plastic, etc...
I was wondering, can wood veneer be used as spacer material? Like the kind of veneer used by cabinet makers and marquetry artists. the really thin, stuff.
I have a collection of veneer scraps of almost every type of wood, and it seems like a good way to use them. I also have some pieces that are a bit thicker than veneer, maybe 2 mm thick pieces of ebony and various rosewoods.
My concern is that because the grain of the veneer would be perpendicular to the tang of the blade, and the grain of the other wood in the handle, it might cause problems with shaping, sanding, and finishing, or it may cause other problems. I'm not sure exactly what kinds of problems, but I figured I'd ask.
Would it be necessary to stabilize the veneer spacers? and if so, how?
I've experimented with this before but on the test pieces I tried, I couldn't get a good result. One of the problems was exactly as you guessed - shaping. Even with a really tight glue joint, it was relatively easy for the veneer to tear or split if you worked it too fast, or too aggressively.
A second issue you risk is warping caused by the veneer. It sounds crazy to say such a thin piece of material can have that kind of impact, but the thin pieces of stock are prone to expand and contract pretty aggressively and they can do some damage. This is part of why veneer in the furniture making world is usually put over a highly stabile base like plywood or MDF and why only certain types of glues are used. For similar reason, to provide counter acting forces, most makers veneer both sides of their panels and not just the visible side.
With a handle, I was concerned that sandwich in a piece of raw veneer would eventually cause cracking or separations as the veneer tried to curl/cup/warp/expand/contract.
You can try and offset the movement risk by sandwiching a couple pieces of veneer together with the grain of each running in different directions. That sort of creates a plywood like effect. I, personally, didn't like the look...and it only magnified the shaping challenges.
Another approach would be to pretreat the veneer pieces with glue to stabilize them somewhat. I've seen this done in marquetry work. Process is simple - paint on a basic white glue and then let the pieces dry either under weight or clamped to stay flat. One or two passes of this and the movement risk will be significantly reduced. The negative is - finishing. The glue would act as a barrier to an oil coating....so you'd typically seal it with shellac first before applying a finish. That's not ideal for a handle...
In fairness - have to add - I only experimented with veneer for a handle for a little bit and then decided to go with tried and true and not take the time to figure it out. I suspect it can be done, and done well... but there's definitely some trial and error involved in getting a result that's both good...and durable.
Any thoughts on slightly thicker wood? 2mm or so.
The grain would still run perpendicular to the tang.
Is it the thinness of the wood that is a problem? or is it the direction of the grain that causes problems?
I'm thinking of using this as a spacer in a hidden tang knife, so it would be a small disc separating the bolster/ferrule from the main handle
I've used veneers as spacers on Yo handles with no ill effects. Epoxy will help stabilize it and for your application it ought to work just fine. Are you using a dowel to hole handle to ferrule?
yes, I was planning on using a dowel to connect the segments.
In the past I've sawn (sawed?) the dowel in half and used a dremel and chisels to make a groove to accept the tang. The tang fits inside the split dowel, and the dowel fits inside the drilled handle segments. Not sure if it's the most efficient method, but it seems to work.
So for the Yo handle, was it a spacer, or more like a liner for a full tang knife?
Because a liner seems like it should work better, since the grain would be parallel to the tang and the other layers of wood.
Direction of the grain will have impact on how the pieces move... but I think the thickness of the veneer is the bigger factor, for sure. Take a thin piece of scrap veneer and wet it with water....then look how much it curls once dry and you'll see what I mean. Different species will vary, but regardless of the type, on the really thin pieces of veneer you don't have the benefit of the additional wood fiber to help resist the curling or movement so they move a lot. For sake of metaphor - it's much easier to scrunch up a piece of paper than a whole phone book. No exaggeration - I've seen panels made for cabinets or table tops warp (cup) from the veneers movement if the maker didn't plan for this. On a handle, of course, you won't have any where near that kind of movement because you're dealing with a very small spacer piece, still ...it was my fear that there would be enough movement to separate the joints or cause some noticeable changes to the handle. Given the hours that go into making a custom Wa handle, it would be a shame for it to end up with defects a few months in....and that's a real risk. I'm sure it's solvable - I just didn't take the time in my own efforts to play around with it much
Originally Posted by hobbitling
To your question - Using thicker veneer stock will reduce the problem risk. How much will depend on the type of wood, the grain pattern (straight, burly etc) and how stable it is....
On a yo handle, I don't think this is much of a concern because you have the rigid metal tang as the "backer" for the veneer....it's a lot more rigid than a piece of wood. Also, since you're gluing the veneer spacer/liner to both sides of the tang/build on a Yo - you've created opposing forces (From the two opposite sides of the handle) to off set each other. On a Wa handle, you are faced with a very different scenario....one piece of veneer moving (no counter balancing force), and wood to wood joints where movement will be more pronounced
As for a dowel - that may not help much for paper thin veneer (2mm, different story) - though the dowel's always a good idea with mixed materials - it won't serve the same purpose with a thin piece of veneer that it does with other mixed materials like metal (With metal spacers, for instance, the dowel acts as more of a "mechanical joint" that maintains alignment....It increase the surface area of the glue joint, too...but the mechanical aspect is particularly helpful because it takes some of the burden off the glue joint for holding things together and aligned (a factor given the different ways metal and wood move with temperature changes, and the difficulty in getting great glue adhesion on some metals)
I'd try it with a thicker piece to see what happens. Could turn out great and be a non issue...
I think I'll try a few test handles and see how it goes.
put it through the dishwasher and a few other worst case scenarios and see how it holds up.