using WET softened veneer

[Steven Levi]

Hi all,I have made a complex conical-shaped structure with wiggle wood and cross veneer over a complex form in a vacuum press bag for an abstract chair and dresser project. See attached image. I am having difficulty working out the next steps and was wondering if anyone has experience with something like this?


The final veneer will be waterfall bubinga with the grain going in the opposite direction. I will need to apply veneer to both sides. One of the tricky bits is that now that the initial structure is rigid, I will need to bend the veneer, both inside and out to the tight diameters, especially at the bottom, without the veneer cracking to shreds!!!!


I had an email correspondence with someone at veneer systems about using a veneer softener. The idea would be to use the softener to saturate the veneer and then apply the WET veneer to the structure and then slide it onto the form. He says other customers have done this but you must use a UF resin glue.


Has anyone ever done something like this? When do you seam and tape the joints relative to the softner? Likewise, when do you cut to shape? Is it before or after the softener?


Thanks for any input,
Steve

[Kevin Jenness]

I have used veneer softener to smooth out wrinkled veneer but have always dried it out before use. The dried conditioned veneer is more flexible than before conditioning (partly, I think, because glycerin is a humectant) and it should conform to the curve you show but you would have to experiment. I would be cautious about laying up wet veneer and anticipate problems like seams opening up. On the other hand, if Darryl Keil recommends it it probably works. I definitely would experiment before committing to the finished piece. I think you would have to do any seaming and taping after conditioning but again I have doubts about using conventional veneer tape or glue on wet material.

[Steve Demuth]

I'm trying to understand where the issue is coming from. Isn't the surface to be covered an actual cone? And you intend the grain of the veneer to run in the long direction (the axis of the cone)? If so, then is the bending really all that complex? Don't you want to cut trapezoidal pieces of veneer and then tape them together to form a flat section of a circle that can be wrapped into an actual cone to glue to the substrate? If so, then I don't think the bends will be all that problematic, since they will be bending across the long grain of the veneer at every point. I'd just tape the show surface of the veneer generously with masking tape to make sure the grain doesn't split and separate, and wrap the thing around your form, and vacuum clamp it down.

[Kevin Jenness]

I'm trying to understand where the issue is coming from. Isn't the surface to be covered an actual cone? And you intend the grain of the veneer to run in the long direction (the axis of the cone)? If so, then is the bending really all that complex? Don't you want to cut trapezoidal pieces of veneer and then tape them together to form a flat section of a circle that can be wrapped into an actual cone to glue to the substrate? If so, then I don't think the bends will be all that problematic, since they will be bending across the long grain of the veneer at every point. I'd just tape the show surface of the veneer generously with masking tape to make sure the grain doesn't split and separate, and wrap the thing around your form, and vacuum clamp it down.

Yes, bending across the grain should not be a problem.

[Richard Coers]

I can't imagine getting gum tape to stick to wet veneer, nor painters tape as far as that goes.

[Steven Levi]

I'm trying to understand where the issue is coming from. Isn't the surface to be covered an actual cone? And you intend the grain of the veneer to run in the long direction (the axis of the cone)? If so, then is the bending really all that complex? Don't you want to cut trapezoidal pieces of veneer and then tape them together to form a flat section of a circle that can be wrapped into an actual cone to glue to the substrate? If so, then I don't think the bends will be all that problematic, since they will be bending across the long grain of the veneer at every point. I'd just tape the show surface of the veneer generously with masking tape to make sure the grain doesn't split and separate, and wrap the thing around your form, and vacuum clamp it down.

Yes, the veneer will be applied to the actual cone and in the long direction. And yes, it will need to be cut somewhat as a trapezoid with convex and concave curves at the top and bottom.

I tried a small piece and the veneer (from certainly wood) started to crack. I cannot take chances of cracking happening on the real thing. The inside has to be pressed into the cone and conform to its shape so that it can be slid on the form. The outside will have a full sized tape-coated hardboard caul protecting it from the veneer bag. The Inside on the bottom I has a diameter of 10” and the cone is 270° of a circle.

I will experiment with softening and letting it partially dry to see how dry it can get and still yield pliability.

[Steve Demuth]

I don't know what you've got for forms to work with from the initial bending, but you might consider softening the veneer, applying it to the form, and then drying it clamped on a form or in a vacuum bag in the required shape, then fitting an gluing the bent veneer, rather than trying to bend and glue it in a semi-softened form. I've done this in order to wrap really fragile burl veneer around relatively sharp curves.

Drying softened, wet veneer, BTW, is a nontrivial process. If you haven't done it before, I recommend reading up on the process, and following an experts advice on how to use kraft paper to draw out the water, change frequency, and timing.

[Richard Coers]

Why not steam or give it a hot water bath, then vacuum press into a form and let it dry. Then laminate to the final form. Trying to do it in one step is not a great idea in my opinion.

[Steven Levi]

I don't know what you've got for forms to work with from the initial bending, but you might consider softening the veneer, applying it to the form, and then drying it clamped on a form or in a vacuum bag in the required shape, then fitting an gluing the bent veneer, rather than trying to bend and glue it in a semi-softened form. I've done this in order to wrap really fragile burl veneer around relatively sharp curves.

Drying softened, wet veneer, BTW, is a nontrivial process. If you haven't done it before, I recommend reading up on the process, and following an experts advice on how to use kraft paper to draw out the water, change frequency, and timing.

That’s an idea! Yes, I could mold the wet veneer to the form use Kraft paper, put it in the vacuum bag and get it to the approximate shape before actually trying to apply it. Of course, the inner and outer veneers have slightly different radiii

attached is an image of the form

[Steve Demuth]

I think you've got everything you need with that form, and your vacuum bag. I'd dry it as Richard and I both suggested on the form, then glue it onto the final armature after it's dried in shape.

I don't think the radius difference will matter. The bend doesn't have to be a perfect match in order give you a satisfactory veneer glue up.

Since you've never done this particular maneuver before, if you have some low value scrap veneer around, I'd include that in the drying to shape step, and learn the mechanics of wrestling the curved veneed onto the armature with that, before risking your waterfall Bubinga. You'll probably learn some valuable tricks.

[Steven Levi]

Thanks, Steve

am still not sure when to tape the veneer together and shape it to the curved trapezoid. It seems like it has to be done before the veneer is pressed and dried?

[Steve Demuth]

Neither veneer tape (gummed paper) nor masking tape will stick well at all through the wetting process. You could tape the sheets together when still flat and dry using paper impregnated with some CA gel, and then remove it after with acetone. I've done some temporary glue ups that way, although not specifically for this purpose. But I'd probably bend and dry the pieces oversize in the proper orientation on the form, then after then are dried into shape, cut and tape them prior to glue up. You'll need to do the cutting and taping on the form, of course. It should be fairly straightforward as you'll being making straight edge guided cuts down the length of the cone. First, gently tape the formed veneer to the form in the right orientation. Getting the cut in the right place and orientation should the be pretty easy. Lay down a couple of layers of painters tape under where you'll be cutting, if you want to protect the form for future use.