How to apply venner to inside and outside radius?

[Chris McGee]

A client has asked if I can produce a veneer covered waterfall coffee table like the one below. I have only done flat veneer in a vacuum bag up to now. I have two veneer books and neither covers this type of form. I was wondering if i could just slip the whole piece into a vacuum bag like a sock, maybe adding a curved padded caul for the inside radius? Any ideas or resources anyone could recommend? Probably using raw wood mappa Burl or Maple burl veneer.
Burl Waterfall Coffee Table.jpg

[Edward Weber]

I would ask someone like Scott Grove, who is wise in all things veneer.
https://scottgrove.com/
The grain direction may be the most difficult part to deal with. The veneer may need to be softened or steamed to achieve the curvature of the table

[John TenEyck]

I would consider applying your veneer to 1/8" bending plywood flat in your vacuum bag, and then gluing that to your rough bench form, again in the vacuum bag. I'd do the outside separately from the underside.

John

[Jamie Buxton]

I agree with John. Burl is pretty fragile stuff, and you’re going to doing rough things to it. You’d be better off first sticking it on a backer. It is possible to buy 4’x8’ sheets of 2-ply veneer, where something sturdy and inexpensive is the back layer. Tapeease.com is one source for 2-ply in many many species. They do mention Mappa, but it is not cheap.

[Andrew Hughes]

I think it would be easier to learn the art of Scagliola.
Veneers are prone to bubbles and lifting not much room for errors.
Id march away from that project
Good Luck

[johnny means]

You should be able to just apply the veneer and put it in the bag. The problem will be getting the complex shape to press evenly in the bag, while staying where you want it to without damaging the veneer. I would do one side at a time and evacuate very slowly, so I could work the bag as it compressed. It's meet terribly complex, just hard to control.

[Don Stephan]

Several years ago, Darryl Keil at Vaccum Pressing Systems made a video on vacuum veneering curved surfaces. You might contact the company and see if the video still is available. Experimenting first might avoid disaster. I have made two ply several times, but always glued to a flat surface. I don't know how flexible they are or how tight you radius would be. Certainly Wood has always been a great veneer supplier for me.

[Chris McGee]

Several years ago, Darryl Keil at Vaccum Pressing Systems made a video on vacuum veneering curved surfaces. You might contact the company and see if the video still is available. Experimenting first might avoid disaster. I have made two ply several times, but always glued to a flat surface. I don't know how flexible they are or how tight you radius would be. Certainly Wood has always been a great veneer supplier for me.

You should be able to just apply the veneer and put it in the bag. The problem will be getting the complex shape to press evenly in the bag, while staying where you want it to without damaging the veneer. I would do one side at a time and evacuate very slowly, so I could work the bag as it compressed. It's meet terribly complex, just hard to control.

I would consider applying your veneer to 1/8" bending plywood flat in your vacuum bag, and then gluing that to your rough bench form, again in the vacuum bag. I'd do the outside separately from the underside.

John

I agree with John. Burl is pretty fragile stuff, and you’re going to doing rough things to it. You’d be better off first sticking it on a backer. It is possible to buy 4’x8’ sheets of 2-ply veneer, where something sturdy and inexpensive is the back layer. Tapeease.com is one source for 2-ply in many many species. They do mention Mappa, but it is not cheap.

Thanks all for the replies! I talked to Darryl Keil at Vaccum Pressing Systems today and he said it was possible to slip the whole piece in a bag to press. As John and Jamie suggested Darryl highly recommended gluing the raw wood to a piece of 1/8" italian bending poplar flat in the press before applying to the actual piece. I'm going to do some tests and see how it goes.

[Jamie Buxton]

Do test to see if veneered bending poplar will bend to the radius you need. Bending poplar is magic stuff, but it does have some limits. That's why I was suggesting 2-ply veneer. It is thinner, and is more likely to bend to your tight radius. I think I'm seeing a radius of perhaps 1.5" on the inside bend.

[Kevin Jenness]

That is a tight curve. I think you will want to soften the burl, back it with something and make sure the laminate will bend to your radius. Getting it tight to the center flat and both inside corners will probably require pulling a partial vacuum, massaging the veneer into the corners and then applying full pressure. UF or epoxy would probably be appropriate.

Veneering convex curves is a lot easier. I wonder if it would be worth making a mirror form and laying up your two ply or veneer+bending ply over the outside of that before applying it to the inside of your table.

It's possible that backing the burl may be unnecessary if it is softened first. In any case some testing is in order.

How will you construct the shape? Torsion boxes with solid shaped corners?

[Jim Becker]

This kind of project may actually be well served by doing a bent lamination with hard-cauls, especially since the veneer needs to be on both sides of the core. And yea...burl really wants to be well supported or it's going to fall apart and you manipulate things. Building an clamping will be a "fun" thing for something of that size, however.

[Jamie Buxton]

This comment isn't about the veneering problem. Instead, it is about the corners where the 2"-wide surfaces meet the 20"-wide surfaces. Those corners have veneer on both sides of the corner. I really try to avoid that kind of corner. The edges have to meet at a knife edge, because if you relieve the corner just a bit you go through the veneer. I don't like the feel of that knife edge. Also, the knife edge is sensitive to dings and bruises. I'd try to talk the customer into some other design that doesn't have that bad corner. And if you're redesigning the piece, maybe you can get yourself out of bending the Mappa burl around that tight radius.

[Alan Lightstone]

Veneering convex curves is a lot easier. I wonder if it would be worth making a mirror form and laying up your two ply or veneer+bending ply over the outside of that before applying it to the inside of your table.

I've never tried that, but it sounds like a pretty good idea to me.

[Chris McGee]

in my version I made the radius larger to try and facilitate easier bending.
My rendering
bwfct r1edit.jpg