Best way to attach the top of an A & C sofa?

[Jay Knepper]

I'm in the midst of making an Arts and Crafts style sofa (from one of the Shop Drawings for Craftsman Furniture books by Robert Lang) and I'm thinking about how to attach the top. The design is post and frame and panel construction topped off with a ~8" wide U-shaped cap that covers the arms and back.

The cap will be the only thing that's easy to grab when the sofa is moved so it will have to be well attached to the frame.

The sketch shows one post and part of the frame. The cap will sit on the posts, the top edge of the rails, and 7 corbels. The two corner joints of the cap itself will be mitered and joined with dowels and glue. The rails will provide the only long-grain glue surface between the frame and the cap. There will be about a 10:1 lever arm working on the effective gluing area when the sofa is lifted by the edge of the top cap, so I'm thinking that something in addition to the long grain glue joint will be needed.

I'm considering:
1) Dowels to connect the corbels and top cap
or
2) Screws angled upward through the corbels into the underside of the top cap.

Your thoughts?

[Jamie Buxton]

I don't think the dowels add much to the glued butt joint. Using the corbels structurally -- with screws or whatever joining means -- will add lots of strength.

[Art Mulder]

Jay, I completed this Mission style Loveseat two years ago. I also struggled over how to attach the top arm-rest.

In the end, I just trusted to the strength of glue - and also put in about 10-15 biscuits. However, I am also conscious (and is my wife) of trying to never lift it strictly by the arm-rests.

Two years and it is doing well. But yeah, I'd like to hear from someone who has a 10-15 year old sofa and how it is holding up.

[Bob Marino]

Jay,

I built a similar unit a few years back and I agree with Art - I used bisquits and corbels. And as Art also said, I am careful not to pick up or move the sofa by the armrests.

Bob

[Dave Richards]

How about epoxy instead of glue? paint a coat of unthickened epoxy on the faying surfaces and then butter the rails with a little bit of slightly thickened epoxy to ensure that any small gaps get filled. Clamp firmly but not overtight. After the epoxy cures it won't come apart.

If you want a belt and suspenders approach to keeping it together, drill holes as if for dowels. Use bits of threaded rod instead of dowels and epoxy them in place.

[Bob Lang]

I'm of the opinion that the glue joint is enough. Try gluing an 8" wide piece of scrap to a piece the width of the rail and try to break it. Some way of reinforcing it might make you sleep better at night, and I would refrain from lifting by the cap pieces. I wouldn't use dowels, but biscuits would be a good choice.

The simplest way to strengthen this joint is to run some screws up from the corbels into the arms. The corbels are there to support the arms and will prevent the leverage you are concerned with. Plug the holes on the bottom edge and no one will ever know they are there. The other bit of insurance you can add would be figure 8 fasteners along the top rail and into the arms.

Bob Lang

[Kirk (KC) Constable]

I've made a couple prarie box chairs, and I screwed down through the 'arms' into the rails and flush-plugged the holes. I might use slightly raised square plugs if I do it again.

KC

[Jay Knepper]

Thanks to all for your responses, the've been a real help.

I think that I'll glue the long grain surfaces and angle some screws up through the corbels into the top cap and plug the holes. For some strange reason I've never been "at home" with epoxy--perhaps too many failed attempts at repairing glassware? Screwing down through the top is a good solution, but I prefer to leave the top "clean" since the purity of the original design has a lot of appeal to me.

I wonder how the originals were done?

Lovely job on the sofa, Art. It's a nice blend of A&C with contemporary design and beautifully executed.

Robert, thanks for publishing the books. They're my most-used source of designs.