Whether it’s a circular veneered table apron, a contemporary laminated chair back, or a flowing architectural column, if it’s a curve made with wood it’s most likely created using a process called bent wood lamination. One of the most common ways of pressing and clamping these laminations is to use a vacuum bag system.
In this video, the journeyman cabinetmakers at the Robert Treate Hogg Cabinetmakers give us a complete introduction to this versatile and useful technique. It’s a process they use almost daily. RT Hogg’s president, Michael Hoffmeier describes their method, which centers on the use of specialty 3/8th inch flexible plywood. This remarkable material (also known as wacky wood or bending plywood) can be easily formed into tight curves allowing the artisan almost unlimited design possibilities. First, the core is glued-up, vacuum pressed, and dried. And then the finished veneer is applied. With experience the process is efficient and highly controllable. In this video, learn about proper glue selection, flexible ply construction tips and tricks, vacuum bagging and veneering skills. — Keith (9 Minute Woodworking Video)
Robert Treate Hogg Cabinetmakers (pronounced “Hoge”) hand-make commissioned, limited production furniture, architectural cabinets and fixtures. Originally founded in 1936, Hogg specializes in high-end audio-visual lecterns and podiums for higher education. They are based in Oxford, Pennsylvania.
I haven’t done any veneering yet, but I have been reading about. Everyone talks about putting veneers on both sides of the substrate, to keep it “balanced”. Did they add a secondary veneer to this piece? If not, what are their views on the need to “balance” the veneers?
You are correct, both sides should be veneered to balance your work piece and minimize movement. This was done on the substrate that was videoed but unfortunately did not get articulated enough as well as we should have. Although, I have seen alot of antique pieces of furniture where the table skirts and/or drawer faces were only veneered on the exterior surface with a figured wood such as crotch mahogany and they held up fine. I believe this is do to the substrate, which in those cases were quite thick and constructed from solid wood, were strong enough to avoid movement. As a general rule, it is a common practice to balance your work piece.
its not important to veneer both sides when its a curved object because it will always “kick back” a little. But when laminating flat pieces you have to laminate both sides!
How much vacuum were they pulling for that large part and how do they determine how much to pull? Is this trial & error or is there a way to calculate it? How about for the home workshop? What’s available?
Is there any recommended supplier for curved pool bridge with height of 1.4m of my design?
Keith’s Note: I’m sorry, but I don’t now how to answer that.
Really nice technique didn’t know how to make things like that.
Nice video. What kind of glue are you using and what is the open time? Thanks.
Keith’s Note: Nothing too exotic here. Michael Hoffmeier and his team use the common PVA glue, but in this case it is the white variety, which has a longer open time — a requirement for “cold press” or veneering operations.
Great video. Was the veneer paper backed or single ply? And what size was the vacu press?
Keith’s Note: The Vacu Press was, I believe, a 6 cfm model. Go to the Vacu Press website for more information. I don’t recall whether the veneer was paper backed/multi-ply, but give the flatness of the veneer in the demonstration, it was almost certainly not a single ply/non-backed veneer slice. Great questions. BTW, as you may have already noted, it was a figured Anigre, which is a common architectural cabinet material because of it’s consistent color and grain. It is often stained to simulate cherry.
Attaching teflon furniture moving skids to the bottom of the form would make moving it in and out of the vacuum bag much easier.
On Thu, Nov 3, 2011 at 7:23 PM, ben brewer wrote:
I have a hope chest that I am refinishing in veneer, and on the front of the lid it has a curve. What is the best way to get the veneer to stick in that area? This was manufactured in a factory, probably 50+ years ago. Would I need a vacuum like it showed in the video? Or can I do it with tools at home? Thank you for the help in this.
Keith’s Note: You could use a vacuum press, which is probably the technique most modern woodworkers would use, but a cheaper approach (and some traditionalists would say a superior method) might be to try the traditional hide glue technique as is demonstrated in this video (Hammer Veneering: How To Apply Decorative Veneers Using Only Hand Tools). The advantage of using hide glue is that it is probably a less expensive way to go and it is also reversible and can be undone if things go wrong or a repair is required at some later point. For me, I’d probably go the hide glue approach. Good luck and keep us posted on your success.
Hi – Is there water evaporation because of the vacuum? Does the glue cure faster? Thanks
Keith’s Note: Evaporation is part of the process. The pressure doesn’t really speed up the process, it is simply a means to “clamp” the veneer to the substrate.
I’ve recently replaced my bagpress with a Curvomatic Infinty laminating system which makes the mould as well as providing the clamping pressure. It makes my bagpress seem very messy and difficult. (And this new system helps with) the problem of making moulds. I’ve been using Titebond Extend glue as it does not creep like PVA does over time.
Hello, I’m not sure if this is the correct section, but it seems most suitable for my project. I’m building a wooden bike frame from planed beech planks of roughly 3mm thick, there will be over 15 planks building up to a 40mm plus thickness. This frame once all planks are glued will be clamped with F-clamps around a pre-cut chipboard former made for the top and bottom sets. I don’t own a vacuum system and as you are working in thinner veneers it probably wouldn’t be suitable.
But I’d like your opinion regarding suitable glue for that many layers. Would PVA suffice or would you recommend a better adhesive to eliminate creep and fight the kickback that many would give?
Keith’s Note: You’ve got me on that one. I’ve never built a wooden bike frame. :-)