Veneer pros discuss vacuum bag and other techniques for making veneer conform to a three-dimensional surface like the gauge panel of a Jaguar automobile dashboard. August 8, 2010
Question Does anyone have an idea how this veneer was applied to follow the contours of the gauges?
Forum Responses (Veneer Forum)
From contributor G: Isn't that solids?
From contributor P: Are you sure it's veneer? Maybe it's plastic - hard to tell under that finish.
From the original questioner: It's definitely veneer; it's how all early Jaguar dashes were done. The backing is plywood, many thin laminations similar to applecore. I had an early one delaminate, so I know it's veneer. I just can't see how they continue the veneer around the corner.
From contributor J: I seem to remember a Fine Woodworking article about applying veneer on a demilune table and having the veneer wrap around the curved table edge. After gluing up the core and veneer with epoxy and bagging the part, the guy sucked out a good volume of air, then stopped the pump. Judicious application of a rubber roller started compressing the tiny creases that resulted. More vacuum, more rolling, etc. until the bag was down all the way. After the epoxy kicked, the bag was removed and the resulting lumps were sanded smooth by hand, yielding an apparently acceptable result (or judicious Photoshopping - one never can tell). I suppose the species and cut of the veneer would determine how well this works. I've never had to do this method myself, but if I did, I'd probably try some burl because there's a lot of potential grain stretching and compression that needs to go on. Being that burl is mostly end-grain no matter how you slice it, it's amazing how much it will stretch. I've cut plenty of square panels only to watch them turn into parallelograms once I get them wet with glue.
From contributor A: Maybe the finish is polyester and 1/4" thick. The veneer could be almost flat with a pile of molded resin on top of it to give it that 3D look.
From contributor C: Are you sure its true wood veneer? Thermofoil should be able to do that shape easily, from my limited knowledge of the process.
From the original questioner: This is absolutely wood veneer. It's not solid and although it has many coats of poly, underneath it's veneer. This dash is from a 1957 Jaguar, so the process is not new, nor the result of any chemical treatment I'm aware of. A mystery to me.
From contributor A: Like I posted before, what if the veneer is virtually flat? The finish could be polyester, literally molded 1/4" thick in the angled locations. Polyester would work for that application.
From contributor T: That is an obvious bevel... A thick clear coat with a bevel (or a piece of beveled glass) could not create the illusion you imagine.
From contributor A: I do not believe the veneer is curved. I've done a great deal of molds and laminating in glass/resin. I believe you could produce this effect with the finish, not the wood. The whole part was made on a compound curved mold. You can't bend veneer that way. I might be wrong, but based on that enlarged photo, I still come to the same conclusion. The entire part is obviously made of different pieces of veneer (the top for instance), but the gauge aspect are complete, continuous veneer.
From contributor N: I have been watching this for a bit and finally asked the Vacupress forum. Here was a reply from a very knowledgeable production guy.
"Assuming it is veneer and not solid, these are usually done in a membrane press, similar to a vacuum press but the bag or pressing medium is silicone. The veneer is ultra thin to conform to the contours and cut outs. The same principle as a PVC cabinet door which is covered with a Mylar or PVC coatings. Also referred to as profile wrapped doors. I've seen one of these machines in action at the woodworkers show in Atlanta. If it's solid wood, it was clearly done on a 5 head CNC."
Here's a good video.
I also saw a program on the history channel in regards to the making of a Rolls Royce and they profiled the dashboard process, showing a walnut burl dashboard in a membrane press.
From John Van Brussel, forum technical advisor: These are a multiply product using fleece backed, flexed and sanded veneer. In the current manufacturing process, a foil is also added as a fire barrier. It is a very high tech procedure and would be very difficult to replicate in a one-off. The key here is the fleece backing and the flexing, which allows the veneer to conform to these various curves without breaking.
From contributor I:
Is the fleece backed veneer available anywhere in particular? I have some fleece backed bamboo veneer, but I'm sure it's not the same thing as this is thick and would break easily.
From contributor K: Contributor J, you have a good memory, as your description of how it was done in that FWW article is pretty close to how I did it. The thing I would add to what you said is to wipe the veneer with a wet sponge in the area where the veneer has to do the three dimensional bending. This helps achieve the extra compression or stretching of the veneer without cracking. You are also right that burls do this better than regular grained wood, especially walnut burl. Sometimes I wonder if that's why almost all dashboards and car components are in this particular veneer.
You folks out there with vacuum presses should play around with this technique on some sample parts. You'll be amazed at what you can achieve, not to mention it's fun. With a little practice and patience I think almost anyone could successfully veneer the dashboard shown in this post.
By the way, the veneer I used on that table in the article was birdseye maple, which works fairly well. Not as good as walnut burl though.
From contributor N: Maybe the veneer was clamped in a press/mould with male and female parts. The veneer could be wafer thin and steamed so it was thoroughly flexible. I have seen this done on furniture occasionally.
From contributor E: Forming veneer around these types of contours is still widely practiced today. I have 10 years experience in automotive wood trim manufacture, both at Bentley and currently at Rolls-Royce. The way we do it, using unbacked 0.5mm thick veneer, is either by a die pressing method which uses a high pressure die press and corresponding male and female tools, or using a membrane pressing method which uses a liquid glue and a lower temperature than the die press, which is around 140°C. There should be around 15% moisture content in the veneer, and burr veneers work more readily than straight grain veneers, which tend just to split.
From contributor U: I am the person who makes these dashboards. I came across this thread by accident and I must say that I am more than highly amused at some of the comical theories listed above. This is standard thickness wood veneer which folds down perfectly into the circular gauge bevels with almost no cracking. No one would believe the process that I use and I am not inclined to discuss these secrets. I believe that this is knowledge that only an apprentice or a very determined person should learn. Believe me - it is not easy.
From contributor O: At work we are doing a lot of veneering. All you need is old fashioned evostick, and standard veneer, and a veneer hammer. It is essentially a piece of bronze or brass rounded edge to smooth out the veneer.
The process is: Apply a thin even coat of evostick to the veneer and the plywood. Leave it until it is touch dry (5 minutes). Lay thin strips of wood across the glued surface of the ply, then position your veneer on top of the wooden lats. (This is just to prevent sticking it.) Warning! If you touch the evosticked surfaces, they won't come apart! One by one, remove the lats, pressing your veneer in the final position. Then cut a small enough hole where you want the hole to be (above the hole in the ply) and start to go around the edges with your veneering hammer, pressing the veneer down.
I would go in a spiral pattern, as you shouldn't be able to bend the veneer, but little by little you can achieve this look.
