Bench seat legs

[Frudd]

Hi, to prevent my wife buying a bench from Ikea for the dining table I have decided to try and make one. I have an Ash plank to make the top from, roughly the dimensions will be 1.4m x 300mm x 50mm. I am unsure wether I need to put any cross braces between the legs. Can anyone advise me on this one?

[Robin Fawcett]

Yikes 1.4m - that's just over four and a half feet in old money. I think you'll need at least another pair of legs midway and maybe strengthening the seat where the legs are to be fitted. Probably don't need any stretchers if the holes for legs are at least 40mm.

[emjay]

I wouldn't think you'd need any mid way support on a 2 inch thick ash plank. I'd locate the legs well inboard and splay them out. I'd also taper the ends of the legs and fit them into tapered holes. You could test the rigidity of the plank by supporting it across two chairs and seeing how firm it is.

[croarcher]

Unless you want to put something heavier than 500kg (cca 6 stones in old money) on that plank,I'm sure you do not need any mid way support.

[Robin Fawcett]

Unless you want to put something heavier than 500kg (cca 6 stones in old money) on that plank,I'm sure you do not need any mid way support.

500 kilos is more like 80 stone - you'd be lucky if you could lift that much.

[croarcher]

My mistake with the stones but the kilos are correct; I have made quite a few ash benches with a 45mm (1 3/4" ) and a span greater than 180cm (6 feet) without any significant bending at all when fully "loaded".

[Frudd]

Thanks for the input. I didnt think I would have a problem with the seat bending but I will test it over two supports as suggested once I have finished flattening it. I dont have a means of tapering the holes so I was going to use the 1 3/8" auger bit I have and wedge the legs. Ideally I want the legs to flare to 2" diameter a third of the length from the seat and then taper again to the floor.
Does any of this sound like a recipe for disaster?

[Steve Martin]

One way to make a tool to taper the leg holes is to buy a saw, under several different names but the blade tapers from the tip to the handle, sometimes called a hole saw, about 8"-12" long with a removable handle. Find a relatively hard wood, hard maple, oak, ash, etc. about 6" longer than the blade and large enough in profile to turn a tapering cylinder, so that the cylinder is smaller than the width of the blade, by about the depth of the teeth or slightly less. Sawing a slot through the middle of the wood, wide enough for the blade to slide into the slit but won't be sloppy, usually while rectilinear, for more safely cutting the slot. Then turn the cylinder so that the teeth of the blade will just emerge from the cylinder, when slid into the slit. Prior to turning, drill a 1/2" or so hole across the "handle" area (perpendicular) into which you can place a shaft to turn the auger when completed. After several trials, I used a chisel to cut a 1/4" bevel on each side of the slit, on both sides of the cylinder, allowing the waste to move away from the teeth as the auger is cutting. I also sharpen the opposite side of the blade from the teeth in the manner I sharpen scrapers, to help clean up the surface of the tapered hole. I believe I first read about this in a reference to Jennie Alexander's first book on making a chair or, possibly in a Drew Lagsners blog or other writing.

Trust this is not too obtuse. I now have two of these for varying size leg diameters. They work great!

[Frudd]

I understand. I thought I had seen a video on youtube of someone making a reamer like that but I cant find it now.
Is tapering the leg joints essential? Would a shoulder on the tenon be a suitable substitute?

[Robin Fawcett]

Is tapering the leg joints essential?

Absolutely not - tapered leg tenons are used traditionally on American Windsor chairs. I've never used one and all my chairs, stools and benches are holding together fine...

[Frudd]

Thats good to know.

[emjay]

You can make a nice double edged reamer blade from an old handsaw. A fine tooth hacksaw will cut it. I make mine to 9 or 10 degrees included angle and it is free floating in the wooden base. There are pictures somewhere on this sight. Give it a go.
pip

[emjay]

You can make a nice double edged reamer blade from an old handsaw. A fine tooth hacksaw will cut it. I make mine to 9 or 10 degrees included angle and it is free floating in the wooden base. There are pictures somewhere on this sight. Give it a go.
pip