Thread: Jarrah Workbench Top Thickness

Jarrah is pretty solid and you could get away with less than a 3'' thick top. All depends on the look you are after. 5.5'' is massive but would be a bench to brag about. It comes down to what timber you have and cost. Design is another factor as you only need the front half, less than 12'' for the heavy chopping and hammering. Back half can be thinner, a tool well perhaps.
Regards
John

I was planning to add a tool well at the back, to make the size of the table up to 2' if I felt like I needed it. Trying to make up 20" from probably 2.5" widths would take a considerable number of beams (8), and I'm not sure I even have that many honestly. If I were to rip the existing boards in half, I'd wind up with about the same thickness anyway, maybe less.

My only real concern with a thinner top, apart from it standing up to the abuse of hand tool work, is whether it'll make the big legs look dumb. I was planning on something like 5"x4" legs, from two laminated beam sections. not sure if that's really a good idea or not though. It's difficult to design a workbench with a wood as hard and as heavy as Jarrah, when most of the workbench designers are working in softwoods.

I suppose I'll just have to see how it goes :P

Originally Posted by Mooncabbage

I was planning to add a tool well at the back, to make the size of the table up to 2' if I felt like I needed it. Trying to make up 20" from probably 2.5" widths would take a considerable number of beams (8), and I'm not sure I even have that many honestly. If I were to rip the existing boards in half, I'd wind up with about the same thickness anyway, maybe less.

My only real concern with a thinner top, apart from it standing up to the abuse of hand tool work, is whether it'll make the big legs look dumb. I was planning on something like 5"x4" legs, from two laminated beam sections. not sure if that's really a good idea or not though. It's difficult to design a workbench with a wood as hard and as heavy as Jarrah, when most of the workbench designers are working in softwoods.

I suppose I'll just have to see how it goes :P

Why dont you let your muscles decide the thickness. With jarrah 2 inches would not give but that is a little thin for hold fasts.

There is no such thing as a workbench that is too solid. My idea for workbench design is that excess is barely enough.

What sort of minimum thickness would be required for holdfasts? I suppose I could always laminate another layer of material on the top of the benchtop, although I'm not sure how stable that would be.

Depending on whether you are a mallet maniac or not, the 2.75" trimmed down to 2¼-2½" should be plenty. It wouldn't look silly with the thunder-thigh legs if you put an apron around it, which would be useful anyway. If you find that the top is a little thin for holdfasts (and it probably won't be) you can always glue a 1" thick (or so) 3x3" block under the holes, or run an extra length along underneath if there is a long row of them.

As orraloon says you can just beef up one part for mortising etc. Otherwise you'll end up with a behemoth of a thing that can't be moved around (or indeed put together without much assistance).

Originally Posted by Mooncabbage

What sort of minimum thickness would be required for holdfasts? I suppose I could always laminate another layer of material on the top of the benchtop, although I'm not sure how stable that would be.

This is the specs for a particular brand of holdfast

"The holdfast is used in a 3/4" hole in your workbench top. An 1 3/4" thick or thicker top is required for them to function properly. If your top is thinner you simply add a packer under the bench where the hold is to go. They have a 6 1/2" reach and the maximum clamping hieght is 7 1/4" in a 2" thick benchtop."

so what you are looking at is within the operating range

Cheers

Doug

I'd consider keeping the jarrah for something else.

I agree the workbench should be as heavy as possible. But the timber doesn't have to be pretty.

I'd make the frame out of old heavy recyclable hardwood. M&T with plunge router and table saw, glue and pin. To make it even heavier I'd fill the frame with draws. Just knock up ply draws with heavy duty runners. The bench will be plenty heavy when the draws are full of all your tooling.

And then I'd buy (second hand if you can) the thickest Ply you can find. 30mm thick minimum (even better 2x 30mm sheets) …. Screw that down to the frame. You won't need to worry about bench top movement. Have the ply overhang plenty so that your legs don't knock annoyingly into the frame.

It sounds like shiiit, but ply being so soft means….. you can quickly level it with a plane, and takes the dings moreso when there's a blow, rather than being on your work…..and being a shiiiit looking bench means you'll work faster because it doesn't matter if you drive a drill bit into it, or cut the edge. If it gets covered with glue, you can quickly clean it off with a belt sander….or retrue with a plane. When it gets too many holes in it, spread epoxy all over it, and relevel. If ever you need a bench dog hole in an unusual place you won't think twice about drilling a hole, because its not a precious thing. Put your pride into your work instead .

Bolt a vise/s to the ply.

I'm not using Jarrah out of pride, I'm using it because it's free, on account of I already have it :P Also it's too weathered and buggered for much of anything else. It's solid enough that it'll hold together for a workbench, but ripping it down for boards would result in a rustic look, to say the least. Also I have neither tablesaw nor plunge router, just a bandsaw, a drill press, a thicknesser, and various hand tools electrical and otherwise.

Not generally a huge fan of aprons, however I suppose if they were sufficiently wide for clamping, and flush to the front, they'd probably be quite beneficial. Could perhaps tenon them into the legs or something.

Thanks for the advice and suggestions all, keep it coming :P

Originally Posted by Mooncabbage

I'm not using Jarrah out of pride, I'm using it because it's free, on account of I already have it :P Also it's too weathered and buggered for much of anything else. It's solid enough that it'll hold together for a workbench, but ripping it down for boards would result in a rustic look, to say the least. Also I have neither tablesaw nor plunge router, just a bandsaw, a drill press, a thicknesser, and various hand tools electrical and otherwise.

Not generally a huge fan of aprons, however I suppose if they were sufficiently wide for clamping, and flush to the front, they'd probably be quite beneficial. Could perhaps tenon them into the legs or something.

Thanks for the advice and suggestions all, keep it coming :P

no worries. I didn't realise the Jarrah wasn't flash.

Maybe an alternative to M&T is barton screws. Halving joints and Batton screws maybe with the Jarrah. But I'd still go for thick ply ontop. not a traditional workbench I know, but it would do I reakon. just an opinion. Goodluck.

Well, I disagree with the statement that a bench can't be too heavy! I suppose it's my age, but I cannot fathom why anyone would want benches that need a large crane to move!? We can blame Groggy for the craze, I suppose...

In my view, a bench needs two properties, stiffness & weight. It needs to be stiff, so it doesn't bounce when pounded, & heavy enough not to move around the room when pushed via a hand-plane or whatever. Most of our hardwoods can fulfill these requirements in far smaller sections than you are contemplating. A bench weighing around 80 Kg shouldn't move under any 'normal' woodworking procedure that I know of.

The bench I've just finished making is 1500mm long by 650 wide. The top is 45mm thick except for the dog board, which is 100mm deep, and the apron 150mm deep x 45mm thick. The 650 width includes a 150mm wide tool tray, which has a 15mm thick She-oak bottom. I estimate the top weighs somewhere around 80 Kg, and the legs maybe 25Kg. I had to struggle to lift the top onto the legs, & once there, it makes a perfectly solid & satisfactory bench. The wood in this case is Spotted gum (Corymbia maculata), which has a (dry) density in the range of .9 to .95 depending on whose tables you read, & Bootle gives an air-dry density for Jarrah of .82, which isn't lot lighter. So it would seem to me that almost 3 inches of Jarrah would more than fulfill the requirements.

Holdfasts will probably hold in much shorter holes than usually quoted. Mine will hold in holes only an inch deep, maybe even less, I haven't tried them in anything shallower than that. I think one of the main reasons for insisting on deeper holes is to minimise wear on the hole. The shaft slews more in a shallow hole, and crimps the edges, so that after a while you have a nicely bull-nosed hole & the shaft won't stick when pounded down.....

My 2c,
Cheers

Thanks for the input Ian. Having just manhandled 80kg or so of bandsaw down to my basement, I can definitely see your point. That said, once constructed, my workbench will never, ever leave the basement. I couldn't get it out the door.

Any thoughts on the size of the legs? Also, what's the argument for such a wide apron? Is it flush to the legs? Just about everything I've read suggests having the front of the bench flush with the legs, and avoiding aprons. Not sure how much that is just a fad though, having not previously built any kind of specialized bench for hand tool work.

Weight? My current bench weights heaps, definitely 3 people are required to moved it anywhere. If there was any prospect of it needing moving I would have made it differently,but as it is the only time it will move is if I die or we sell the house. I like to plane a lot of timber so I made sure the bench was super stiff. It has a front apron and is braced on three sides with yellow tongue. This encloses the bench and makes the underside useful for storage. It also added to the weight. As for aprons I can see merit in having or not having them. You do need to have the ability to clamp things to a bench and a front apron can get in the way. That said I put dog holes all over the wide front apron of my bench and I can support and clamp long lengths of timber along the entire length of the bench which is useful for edge planing of long bits of timber.

In the end a work bench is as personal as your underpants. If you dint feel happy to use it, if you do not smile making it and playing weekend games on it it does not matter what anybody ever says about design. And if you say making things for a while you will probably make a few work benches and each will be different.

Flush to the legs? My current bench has the legs and front apron, the entire front coplanar, flush so that the entire front of the bench is a single flat surface. I find this very useful.