Mahogany & Black Steel Dining Table

[Helvetica]

Only steel so far, but the woodwork will start shortly. The idea was to have a height adjustable table, so the threaded bar can raise the frame from the end blocks. The ends were laser cut from 8mm black steel, this shape was given depth by folding and welding steel to it.

Centre connecting pipe is scaffold. End nuts are scaffold height adjustment jacks.

Lots of square profile steel to hold the wood

Now the hard bit - jointing 4 planks of 2" x 14" x 10' mahogany so that the join is near invisible. Moving the planks is tough so some planning is ahead.

The 2" wood will sit inside the frame for 1" depth, so that 1" will sit proud. A 3/4" rabbet will protrude to sit flush with the steel frame, and hide the expansion gap.

I found a Sedgwick CP on eBay to help me get accurate edges for gluing, and to thickness. I might dowel or biscuit the four planks together, to keep everything in place as I glue up. Final clean up will be with hand planes. Any advice well appreciated

 

[MARK.B.]

Looking forward to seeing the finished table, but you are gonna need some muscle to move that around .

 

[scholar]

Looks v interesting.

Won't you need some fixing of the table top to the frame (presumably through the lateral bearers - slotted to allow for expansion)?

Cheers

 

[Helvetica]

Looks v interesting.

Won't you need some fixing of the table top to the frame (presumably through the lateral bearers - slotted to allow for expansion)?

Cheers

Well I have holes drilled into the lateral bearers in case I want to add screws, but I was going to rabbet a centimetre of expansion to all four edges. Do you think each board needs something for expansion?

 

[Helvetica]

Got the frame home. The welding is a little 'rustic' but I think a coat of penetrol will make it shine. My missus wants it painted black though. One man's patina is another man's rusty!

Quick Q:Would anyone recommend adding sawdust to the glue when joining the boards? I'd like them to be seamless. Cheers

 

[n0legs]

Looks cool =D>
Will be watching with interest

 

[AJB Temple]

Imaginative job. I would lacquer the metal work to maintain the artisan character I think.

14" mahogany planks 2" thick had better be super stable and seasoned!. I made a utility room / boot room / rear hall counter top out of 10" mahogany planks 40mm thick and 12ft long and just used rubbed joints as with boards that heavy and working on my own I had to assemble in situ. I used a ply base which was later slid out, to help me do this. If I were making it again the the workshop I would either use stopped T&G ( so the ends didn't show ) or dominos. In your case, given the steel theme, you could construct it like a butchers block and put 5 threaded steel bolts through drilled holes to draw the planks together. I would also be tempted, if you don't have the wood already, to go thicker than 2 inches, and give it a little more drama given the scale of the job.

 

[Helvetica]

Thanks AJB Temple. The mahogany is kiln dried, and has been resting in the dining room for a few months. Thermostat will keep it around 20c all year. Would that be stable enough do you reckon?

I was thinking of butterfly dovetails to pull it together, but not sure I have the experience to pull that off. The plan is to use biscuits to align for glue, but glue only to hold it together. I like your steel bar idea but I don't have a pillar drill to cut straight 14" holes. I have a lathe with a pepper canister bit but I don't think it's built for this! I have a colt forstner blade which cut 6" beech, maybe…

I can always just screw in from the base, but will this stop needed movement?

 

[Racers]

You won't stop the wood movement so matter what you do, its best to make allowances for it, your idea of a rebate and overlap is a good one, leave 20mm or so for expansion of the sides and 5mm at the ends as wood won't move much along the grain.
With the weight of the top you won't need any fixings gravity will hold it in place.

I would use biscuits to align the top of the boards to save lots of work levelling the top, don't mix sawdust with the glue you want the thinnest glue line possible to make a near invisible joint.


Pete

 

[Helvetica]

Brilliant Pete, thanks. Would you think I'll need pipe clamps for this? Also any particular glue ideally suited?

 

[ColeyS1]

I'd say resin just cause because it's fairly foolproof. Or cascamite [WINKING FACE] love the work you've done so far. It looks amazing !!!

Coley

 

[Racers]

Brilliant Pete, thanks. Would you think I'll need pipe clamps for this? Also any particular glue ideally suited?

Normal PVA will be fine, I would glue them up a pair at a time you don't want to be struggling with lots boards and clamps.
Don't fit too many biscuits 5 or so will do and don't put glue on them the last thing you want to do is wrestle with 10' planks that you can't get the gap to close.
The surface area of the planks will be a more than adequate area without needing the biscuits glued as well.

Lots of pipe clamps (one every foot or so) a few helpers and a dry run is the order of the day, you could use the table base as a bench when gluing the planks up.

Pete

 

[AJB Temple]

It's not so much the temperature that affects it, but humidity. But indoors it should be find as long as you follow Pete's advice. I actually used Cascamite for my job and it has been fine, but these days I would use Titebond I expect. Pay a great deal of attention to getting your edge to edge joints perfect. When clamping up, work the clamps up to pressure evenly a bit at a time along the whole table top. It will look fantastic.

Oddly enough I just bought a very large mahogany table and 6 rush seated chairs from a junk shop. The table is 8 ft long and approx 60mm thick. Purchased just to get my hands on the wood! Brown furniture sells for next to nothing and is much cheaper than buying Honduran mahogany when it turns up like this. My wife was a bit surprised when this lot turned up.

 

[No skills]

Looking good, this sorta thing is right up my street.

 

[whiskywill]

Looking good, this sorta thing is right up my street.

It's a personal preference, but I'm glad I don't live in your street. :wink:

 

[No skills]

:lol: Lots of people are glad they don't live in this street - we will be having a party when we leave :evil:

 

[Helvetica]

Cutting the mahogany to rough length before it hits the thicknesser. These planks are so heavy, I'm not looking forward to hauling them 100 metres to the shed.

 

[Bm101]

Following with interest.
You'd be best off getting rid of them heavy offcuts. God who needs that sort of rubbish wood clogging up the frontroom? Post them to me and I will make sure to take all the labour out of carrying them down the garden and storing them for you. No need to thank me. I try to be the best person I can.

 

[Helvetica]

Following with interest.
You'd be best off getting rid of them heavy offcuts. God who needs that sort of rubbish wood clogging up the frontroom? Post them to me and I will make sure to take all the labour out of carrying them down the garden and storing them for you. No need to thank me. I try to be the best person I can.

How generous! However I see a chopping board in my future…

 

[Helvetica]

Found these clips to hold the planks down to the table while allowing lateral movement for expansion / contraction. A biscuit jointer cut a rebate in the support strips for the clips to run in. Should be useful to hold the planks in place for glue-up too.