How would you do this?

[Markem]

Me, one of two ways quarter saw wood (least likely for me) laminating veneers to a form (most likely) {needing a vacuum press}.

Mark

[Leuf]

I've had this idea for a jewelry box floating around for a couple years but until now haven't been able to match up the time to work on it and the nerve to try it. It's going to have curved solid wood doors on the sides that swing out for hanging necklace storage. The door is essentially an airfoil shape, made up from a 2.5" diameter dowel ripped in half and three boards with a 10 degree bevel between them. I'll hand plane the outside into a smooth curve after it's all together. A picture of a test glueup of the three boards:

'm concerned about the door warping though, so I'd like to have something at the top and bottom to help hold the shape. It would seem like I cannot run one board across the grain of the panel, even if I allow for movement in the fasteners the angles would seem to prevent that from working. So I think I need to glue up a short, long panel to match the grain orientation. I'm stuck however on how to make the joint.

The way the grain is meeting is like that of the corner of a drawer, so a half-blind dovetail would be a good choice, but with the multiple angles... that's beyond my skills.

The inside will be covered with velvet - I was planning on just doing the vertical but there's nothing stopping me from doing the entire inside. So I was thinking pocket screws. I wouldn't be able to put them at the back because it's just too short. I'm a little concerned about putting the pocket screws at the end of the board like this though.

So, how would you do it?

-Leuf

[Lew Hodgett]

Take a page from the boat builder.

The boat hasn't been built that has straight lines, at least I haven't found one.

Think about laminations, say 1/8" thick. With a little thought, you could even form a pretzel, I think.

Lew

[Lew Hodgett]

How about thinner, say 1/16" or different, say hard maple stock?

What radius were you trying to bend the Birch around?

Lew

[Leuf]

I did try to bend 1/8" baltic birch around it. Even with kerf cuts it can't make the bend at the front. And if I just have the laminations running vertically it's pretty much the same thing as what I have now. I thought of combining the two approaches, using a half round at the front and bent ply for the rest, but I thought handling the joint between the two would be too problematic.

-Leuf

[Andy]

If you want a floating jewelry box, I think Lew's idea of using boatbuilding techniques would be worth look into. More seriously, I like your curved door idea, and I would probably try it just like you have it glued up. You might want your stock a little thicker so you don't have to worry about how much you plane away, especially since you're primarily planing away your glue joints. Is your stock well-seasoned? I don't see why a curved door would warp any differently than a flat solid-wood door, and as long as you use some good dry, stable wood and seal it well with finish (even if it's hidden beneath velvet), it seems like it should work fine. In fact, I remember reading about a larger-scale (cabinet-sized) curved door recently - I think it was in Krenov's Cabinetmaking book, and I think it was made up exactly as you showed in your test piece. Looks nice, Andy

[Lew Hodgett]

Didn't realize you were using birch ply.

Have you tried bending poplar?

It's plywood designed specifically for bending, the fibers are all aligned the same way.

Lew

[Leuf]

It's about a 1.25" - 1.5" radius. I kerfed it through 2 of the 3 plies but it just cracked, and I couldn't really wet it because the plywood glue wasn't waterproof.

I got the idea for the shape from the guts of an old Victrola cabinet that I took apart. There's a piece in the middle of it that is essentially the amplifier that has all these curves that make channels that keep getting larger. It's all solid poplar. So I had a form to bend around for free. However I don't have any of the vacuum forming equipment to veneer the thing afterward, and I don't think there's any other way to veneer it. I looked at getting that a while back and to get a bag big enough for this it was more than I wanted to put into it. So I said the hell with it and went the soild wood approach like the original. But the original doesn't have to open.

Even if I could do it with laminations, I'd then have the problem of hiding the laminations at the top edge, because it's a door you'd see it when open. And I don't have a good solution for that.

-Leuf

[rmeyer1]

I would use stopped splines carefully placed to escape planing while rounding the door. I would leave the top and bottom of the doors plain after sanding them with high grit paper to a polished look. If carefully constructed and finished I don't believe they would look bad and would eliminate the cross grain problem.

[Patriarch]

[e-mail] wrote in news:1176214894.903011.211530 @q75g2000hsh.googlegroups.com:

This is an approach used by the folks at College of the Redwoods on some of their Krenov-influenced cabinets. It works, and needn't be too heavy.

See of you can google 'coopered doors'. Should be some good things out there.

Good luck!

Patriarch

[Bill in Detroit]

Leuf, In plywood, the grain crosses and the layers pull against each other. To make this small radius curve you are probably going to need veneer with the grain (if any) running the length of the door.

Just a wild guess, but plywood usually doesn't care for any but fairly large radius curves.

Bill

[Leuf]

That's why I kerfed it through 2 out of 3 layers, so it was just the outside layer with the grain in the right direction that had to bend, but it didn't work.

My point is if the plies are all running in the same direction that pretty much negates the stability improvement that making it out of laminations was supposed to provide, so it really isn't any better than making it out of solid wood, just a different way of doing it.

-Leuf

[Leuf]

I believe everything I looked at designed for bending had minimum radiuses in the 3 to 6 inch neighborhood.

-Leuf

[Lew Hodgett]

Then by all means check out bending poplar.

How much material do you need?

Lew

[Leuf]

I think it's going to end up about 5/8ths thick at minimum, we'll see. The original is about that and it's 75 years old or so.

It should be well adjusted, it's been in the shop for at least a year. However the shop is in the basement and when I bring things up into the house they tend to move. Whenever I've assumed stuff won't be a problem I usually find out in pretty short order that I was wrong :)

I'm hoping to use this piece to get juried into the League of NH Craftsmen, so it's got to be done "right" and to a higher level than I have managed before.

-Leuf

[Leuf]

The 1/8" bending poplar has a minimum radius of 5", not sure about the

1/16".

The doors are about 15" high, and about 12" wide, but probably 15" in order to wrap around the front.

The best plan I had come up with for bending was to use a couple really thin layers, then in the middle to use thicker layers and cut it in really narrow strips to get around the sharply curved part, and then a couple more thin layers on the outside. It didn't sound like a whole lot of fun, and I was a little worried lines would telegraph through the outer layers either right away or after a couple years.

I think I'm going to go ahead with the cross grain battens. That part of the panel is only 10" wide, and at the end the batten tapers down to nothing so really it's only about 7-8". If I knock the corners off on the batten it should still be able to move a bit, and we aren't talking a lot of movement even in the worst case.

-Leuf

[Lew Hodgett]

Have you checked out this stuff?

[Bill in Detroit]

Yeah ... I replied before I had read to where you mentioned kerfing it.