Thread: Roubo workbench top made from pieces?

It should work fine provided the glue up is properly done and the butt joints staggered. A lot of commercial work tops are done like that with quite short bits of wood. At 90mm thick it will be solid. The dowels you are thinking about really are not required as they will add no strength. A good glue joint is stronger than the wood anyhow. Dowels, biscuits or dominoes can be used to keep things aligned when clamping up if you feel the need.
Have you thought of making it split top. Reason I ask is you are going to need some help lifting that top on and off during the build. My bench top is pine and I found even a half plenty to handle.
Regards
John

If you don't mind the additional effort, you could use scarf joints to "lengthen" the short bits.

+1 for all that John said. I don't think you need anything thicker than 60-70mm, and holdfasts will work just fine in that thickness. We must remember that the 4" benches made in Europe and America are from significantly lighter timbers. For example, nobody would make a 4" bench from Lignum vitae!

Many thanks for the information above!

I'm amazed to hear that the dowels won't be required - thank you for that information, it will save a bit of fiddle and work to say the least!

Thank you too for pointing out that 2" (50mm) should be thick enough, I hadn't thought this through very much at this point, thinking purely along the old adage of "Make it heavy".

If my numbers are right, Blackbutt is around 900Kg per cube. This bench top will be 2000mm x 720mm x 50mm at 2" thick, and this leads me to a calculation of 900Kg/(1,000,000,000/(2,000x720x50) = 64.84Kg.

I realise the frame itself (also to be made from Blackbutt) will weigh in some too - I have done a rough calculation and figured at requested dimensions, the frame will come to 51.57Kg, leading to a total bench weight of 116.41Kg.

Will that be heavy enough?

Will you be storing anything underneath it? If so, then add that to the weight. I did say 60-70mm, but 50mm might still be ok. Then add the weight of the vises.

Whether or not you can push it around whilst planing will depend on the floor surface. Timber float concrete floor would be no problem, steel float might allow some slip. You still need to be able to move it around by yourself, but be heavy enough to stay still for planing.

Think of it this way: if it were a drunk bloke who weighed 120kgs, would you be able to shove him around easily?

It won't hurt to use dominoes to keep the top aligned while gluing. Once the glue is dry the doms don't add anything to the strength.

Originally Posted by FenceFurniture

Will you be storing anything underneath it? If so, then add that to the weight. I did say 60-70mm, but 50mm might still be ok.

You did - my bad, I somehow connected that in my head (perhaps with a lack of coffee?) and thought 50mm. Can easily make it 60 or 70, given that it's rough sawn at 300mm now, I figure aiming for 4 rips of 65mm in that ought to be achievable, and it'll actually make the material go further

Using the Dominos for alignment is a good idea, I think it'll make assembly a little easier - thank you

I'm not sure though, that I'm going to be moving this bench around - it's going up against a wall under a window, and there won't be a lot of room to move it about in any case. Floor at the moment is concrete - that opens up a whole other can of worms that, when the summer is over, will result in a thread in the Shed section - I have to fit out the entire shed, and get this and other workbenches up and running, so that'll be a whole other adventure!

Back to weight, making it 65mm would make it around 85Kg, and the frame will come to 51, for a total of 136Kg at that thickness.

In terms of storing stuff underneath - there is provision for it, and a separate set of plans (easily designed or purchased) to fit drawer units on the stretchers, but I don't think I'll be using them - the plans for my equipment bench (which consist of chicken scratchings and ideas in my mind at this stage) are calling for an L shaped bench around 6 metres long to fit a mitre saw, motriser, lathe, belt sander, drill press (Bosch bench type), bench grinder and a Tormek sharpening station. That equipment bench is going to have 18 good sized drawers plus other cabinets below, add to that space for tool wall at least 2m wide, and I have a feeling that storage won't be an issue. If it is, I can still put overhead cabinets above the equipment bench too (all this is part of the bigger picture, of course).

Originally Posted by Midnight Man

.....If my numbers are right, Blackbutt is around 900Kg per cube. This bench top will be 2000mm x 720mm x 50mm at 2" thick, and this leads me to a calculation of 900Kg/(1,000,000,000/(2,000x720x50) = 64.84Kg.........

Hi MM

That will largely depend on the source of your blackbutt. If it is old growth, then the density should be around 930 kgs per cube, plus or minus a bit due to forest variability. If it is sourced from regrowth trees then it should be a bit lighter, but if it is sourced from plantation trees then it could be considerably less dense.
https://www.business.qld.gov.au/indu...bers/blackbutt

Irrespective of the source of your blackbutt, MM, it should be considerably denser and harder than the rock maple and beech favoured for workbenches in the northern hemisphere.


Cheers

Graeme

May not help, but very happy with the result.


IMG_3213.jpg

A mix of Blackbutt, turpentine and "I don't remember".
Blackbutt was from the local timber yard, all reclaimed stuff. Hard to work with for me, quite a beginner. I love those hardwoods.

a pair of Terry Gordon's vices lift you above the "quite a beginner" status

Originally Posted by Midnight Man

Back to weight, making it 65mm would make it around 85Kg, and the frame will come to 51, for a total of 136Kg at that thickness.

I made a benchtop from recycled ironbark. At 1800 x 600 x 70 it ended up weighing in at over 100kg. I know ironbark is a bit denser than blackbutt, but my bench is smaller. I glued up the benchtop in 3 pieces. Each 35kg piece was on my limit for manipulating. After final glue up I had to kludge up a hoist to lift it onto the frame and flip it for final smoothing and fitting the vice. I don't think I'd do it again, but the ironbark was free so maybe I would.

May the force be with you.

MM, don't know if you've settled on vises or not, but I am really loving this setup (extra wide face on the HNT):

HNT FACE VISE 1.jpg

Originally Posted by Fuzzie

I made a benchtop from recycled ironbark. At 1800 x 600 x 70 it ended up weighing in at over 100kg. I know ironbark is a bit denser than blackbutt, but my bench is smaller. I glued up the benchtop in 3 pieces. Each 35kg piece was on my limit for manipulating. After final glue up I had to kludge up a hoist to lift it onto the frame and flip it for final smoothing and fitting the vice. I don't think I'd do it again, but the ironbark was free so maybe I would.

May the force be with you.

I forgot to mention, thankfully, I have an engine crane that can be bought into the workshop to assist in moving this thing into final position Used it to get the bandsaw, table saw and jointer/thicknesser going on mobile bases

To be honest, I'm pretty sure I'm going to need it!

Originally Posted by FenceFurniture

MM, don't know if you've settled on vises or not, but I am really loving this setup (extra wide face on the HNT):

HNT FACE VISE 1.jpg

For some reason, I have no photo of this bench - the only ones online are paywalled behind Fine Woodworking membership, but here's a quick overview:

Essential Workbench.JPG

I had in mind to use the Veritas twin screw tail vise for the right hand end of the bench: Veritas® Twin-Screw Vise - Lee Valley Tools - this is actually the vise they used when designing it.

For the front vise, they originally used a vise from Woodcraft: https://www.woodcraft.com/products/e...ase-front-vise - however, I have heard tales of quick release vises doing their thing when one doesn't want to quick release, and thought I'd err on the side of caution. Picked this one from Lee Valley: Front Vises - Lee Valley Tools

Very keen to hear thoughts and feedback on these choices though - I know little and need to learn much!

My personal choice would be to have the front legs flush with the top edge so that large pieces can be secured easily.

As for vises, every different one has its use, so it's a matter of which type you think will suit most of your work. The HNT face vise doesn't rack so no need for packers on the other side when clamping using only one side of the vise. Where it is now is just semi temporary until I build my next bench. What I love about the handwheel is that one quickly learns the amount of force required to just "nip it up". The wheel was one that I chose, and could have had a handle sticking out if I wanted (I deliberately didn't - crown jewels protection). I keep a stick of dowel handy to spin it around when I want max aperture.