Has anyone veneered a sphere?

[Caspar Hauser]

I'm trying to to coalesce an idea and in the process exploring/discarding options. One would be to veneer a sphere or perhaps an ovoid a couple of feet in diameter anyone done this/similar? All comments welcome, just getting my ducks on the same pond before aligning them.
Thanks

CH

[mike holden]

Caspar,
First, I have NOT veneered a sphere.
However, I would like to point out that if you look at a globe, you will see that it is printed in shaped sections and applied to the sphere substrate. This is essentially veneering with paper.
The problem I see is in determining the shape that will fit the sphere size.
I have seen veneered spheres - check out victorian furniture for some, art deco would be another style to look over.
Mike

PS try asking this on the SAPFM forum, sapfm dot org, the period furniture makers know a lot of neat stuff. mh

[Chuck Nickerson]

To reinforce what Mike wrote, old-time globe-makers solved this problem. The good news: I've seen several articles on how they did it (just didn't keep any). The bad news: before computer graphics, globes were expensive for a reason, it's doable but not trivial. Google will be your friend on this one. I think the phrase to search is "mercator projection".

[Caspar Hauser]

Thanks for the direction guys, it's not the geometry which concerns me, it's the mechanics, clamping etc

[Sam Takeuchi]

Clamping would be tough, eh? How about twine and wrap the glove like a mummy. Or if you have a vacuum clamp, you can modify it to be able to vac clamp the whole thing. I don't know, I never tried it and probably never will, so just tossing ideas for your amusement.

[mike holden]

Caspar,
If you hammer veneer with hot hide glue, then no clamping is necessary. You will probably have to make an arced veneer hammer, but since the ones used by the Colonial Williamsburg guys are all wood, this should not be a problem.
Mike

[Cliff Rohrabacher]

Thanks for the direction guys, it's not the geometry which concerns me, it's the mechanics, clamping etc

Get yourself some of that Stretch Wrap they sell at the borg on little hand rolls.

I bought a Case of rolls from U Line several years ago. I've used the stuff like magical pixi dust for all my bizarre clamping issues where I needed lots of holding strength and super flexible conformal clamping. It is so useful once you get some you'll want a case. I keep a roll in the kitchen ( it's better than Saran for lots of things. There are a couple rolls in the shop, and a couple are used in the garden. The stuff is so useful whenever you need holding or sealing power in a weird shape

Need more compression? Wind a few more layers. It's that simple.

[Harold Beck]

Caspar,

I seem to remember seeing a photo in Fine Woodworking of a desk that was covered with two partial globes and then opened up clamshell fashion. I believe it was veneered, you might look through their article index and see if you can find it. I think it was on the back cover,, maybe?

HB

[Caspar Hauser]

Excellent ideas, thanks a lot! I may now have to actually give this a go.

Thanks again

CH

[Doug Shepard]

There was a guy that posted a thread on the FWW Knots forum a couple of years ago that made a large globe. I dont recall for sure if he veneered the surface afterward but even building the sphere would be a big challenge.
I'm also not sure on this but I borrowed this book about 10 years ago
http://www.woodcraft.com/Product/200...d-Joinery.aspx and I'm pretty sure there was some globe making how-to's (or at least hemisphere) in there. I'd want to verify that before you buy one, but I think there's some info there that might be worthwhile.

[harry strasil]

You can orange peel your veneer like making a pressure head or hemisphere on an iron pipe. but you will need to make a matching concave piece to hold it in place while the glue dries, and you will need to make matching concave and convex pieces to form the hot wet veneer to shape to start with.

You will need to layout the sphere full size to get the dimensions of the orange peels which by necessity of the material will have to be rather narrow, by drawing the diameter of the half sphere full size accurately and then dividing the circumfrence into equal pie shaped sections, then drawing lines an inch apart the length of one half, you will only need to do one half as the dimensions will duplicate for the other half.
Draw a center line with spaces on said center line from the center tha equal the spacing along the circumfrence of the sphere on one curved edge and then trasfer the 1 inch spacing width measurements to these lines and then draw the outside line in free hand.
A cad program would be a lot easier.

[Keith Christopher]

I would think something like this.

[Jacob Reverb]

Thanks for the direction guys, it's not the geometry which concerns me, it's the mechanics, clamping etc

I would look into vacuum bagging, a technique that boatbuilders sometimes use. 14psi can add up on a large surface, at least enough to do what you want.

Gougeon Brothers / West System / Epoxyworks magazine may have info online about it.

[Tom Veatch]

There's a topological axiom that you can't comb a hairy ball smooth. That's what you're trying to do by veneering a sphere. It's the same problem map makers face trying to represent the surface of a sphere on a flat plane. It simply cannot be done without some amount of distortion.

You will not be able to get wood veneer to lie smoothly on the surface of a sphere. It works with paper on globes because there's some stretch to the paper allowing it to distort and confrom to the surface of the sphere. There's not much stretch in veneer.

If you can accept that it's impossible to get a smooth surface (not "difficult", impossible) without distorting the laminate, you can approximate the surface of a sphere with narrow strips. The more narrow the strips, the better the approximation.

After layup, if the veneer is thick enough, you can sand or turn the ridges down and have a smooth surface. Think "barrel staves".

Good luck.

[george wilson]

Make the orange slices not very wide,and you will have the best luck. The veneer will not have to bow very much to fit the sphere. I like the stretch wrap idea. You will still need to do some individual adjusting on each slice to get them to fit together nicely. It will be a tricky job. I made numerous lutes and ribbed,vaulted beck 18th.C. guitars while in Williamsburg. Ribs were adjusted with a shoulder plane laid on its side. You will find this a very tricky,long job to get right.

Is there any chance of adding an inlay line between each rib? It would be a LOT easier if you could cover up fitting errors by sawing a line between each rib,and fitting in a line of violin purfling, IF you can saw accurately.

If I had to do this job,I'd rig up the ball between centers parallel to a flat,accurate base. Make a way to index the sphere. Use a tall and wide block of wood that is as tall as the center line of the ball,with a very sharp blade to run along each rib several times,scoring the veneer till it cut through. Then,peel off the excess. Separate the first slice so cut having used hide glue,and use it as a master pattern to APPROXIMATE the successive ribs,which will still need hand planing here and there for the final fits.