Tambour cabinet

[gasman]

First up I had to cut up my two amazing sheets of Spanish walnut. These measured 1350x700 and had to be cut down to 1000x520

I actually cut them both together and ended up with 2 pieces that were so beautiful. Half of this Spanish walnut had an amazing ripple effect so I cut it appropriately to maximise the ripple in these pieces

I had a sheet of 0.5mm thick plastic sheeting which I cut into 10mm strips which were going to go between adjacent strips during the glue up

My original intention was to do the veneering in the vacuum bag - which was stressing me a little as time is short when getting stuff ready to go in the bag and there is always the possibility for slight movement as one puts the items in the bag before the vacuum takes effect. There obviously cannot be any mistakes here as the veneer pattern on strips has to be completely continuous.
I decided to glue up the first slat on each sheet by hand to give me a solid reference face

These two will be the rearmost slats - ie the pieces which will meet together at the rear of the cabinet when the tambour is opened
Actually once I had done here two I decided it would be easier to glue up the slats 15 at a time under direct pressure on the benchtop. The metal container is full of cut-up lead sheet and weighs about 50kg so I used that to put pressure on the rear of the slats and then clamped the front to the bench

So after 4 glue ups I had done one side - 64 slats in total - marked in order in readiness for them being separated - and with the final slat (ie the ones which will meet at the front) not done yet as I need to think about the handles. I might make these front two slats solid walnut with a shaped handle rather like the ones that Richard Jones / Sgian Dubh has on his Torpedore cabinet but need to give some thought to that.
More after the weekend - any questions comments welcome
Regards Mark

 

[gasman]

I have made good progress this week but it is painfully slow going with multiple 'batch operations' required on each of the 130 staves.
Once glueing up was finished on all the staves, first I had to divide them. This had been made easier by the thin plastic trips between each pair of staves. This came out fairly easily then I could use a scalpel to cut between them with the panel face down on a cutting board. Here I have flipped it over just to show the cuts

Meanwhile I cut up a piece of walnut to form the two central staves which I shaped carefully with rasps and sandpaper

First batch job was to clean up the sides and backs of the staves on 180grit sandpaper to remove all the residual glue etc. Once this was completeI could lay them all out on the bench with the two central ones added so I could start thinking about machining the ends.

After some trial runs, I decided to use a spiral cutter in the router table and machined both ends of each stave on the router table until they all looked like this

There were quite a few in which there were tiny chips in the veneer or where the veneer had lifted slightly and all these had to be glued down, or replaced with tiny cutoffs etc. The 'lugs' which will run in the tambour grooves were 6mm thick by 11mm wide but were still too big to run smoothly round the corners of the cabinet
Again after some trial and error I decided not to increase the width of the corner grooves but instead to curve the outside face of each lug so that it goes round the corner easily. After trying rasps, sandpaper or various grits I decided that a small metal file was perfect as it created a very smooth polished finish on each lug. I don't have a close up but here is the first quarter or so done. It is taking me about 3 minutes per stave to do this - but I am nearly there now - just 25 or so left to do

So, all that is left is to stain and finish the staves and then mount them on linen and try it out. I feel the end of the tunnel is approaching.
Cheers Mark

 

[danst96]

Beautiful work, i cant wait to see the final product. I want to tackle a tambour sideboard at some point so this is great inspiration

 

[Fitzroy]

Somehow missed a couple of your updates, this is looking absolutely amazing! The pattern on the veneers and how they matchup at the handles looks fantastic. Brilliant project, totally inspirational!

 

[Sgian Dubh]

... I need to think about the handles. I might make these front two slats solid walnut with a shaped handle rather like the ones that Richard Jones / Sgian Dubh has on his Torpedore cabinet but need to give some thought to that.

You seem to be making good progress. I do think you've made extra work for yourself by shaping each of the tongues at the end of each veneered stave to allow the tambour to negotiate the corner. It would have been quicker to have widened the groove in the carcase at each corner which would have been easily accomplished with a small repositioning of the groove cutting jig plus an additional short corner run with the router - eight small repositions in all, plus a bit of sanding and chiselling to remove any steps. Still you have found a way to get over the technical challenge of sliding the tambour around the corners, so that's the main thing.

I think I can approve of your handle/pull choice, ha, ha. Slainte.

 

[gasman]

Thanks all. I agree it is a lot of work Richard but I am more confident now with this method that my 65 staves on each side going round two corners will slide smoothly whereas I was not that confident on being able to cut the widened grooves at each corner perfectly. I do not have access to a CNC system and I think you cut yours on CNC if I remember correctly? I also think that finishing the ends with a file has turned out to be an amazing solution as the 'lugs' almost look polished now and therefore have less friction that if they had been cut or sanded. The staves are made of a dark hardwood like sapele or another of the many 'mahogany' species and are quite corse grained and tend to splinter. So the fine metalworking needle file has made the ends much smoother I think.
I always said I was going to copy your handles Richard - I think they are inspired!

 

[Sgian Dubh]

... I was not that confident on being able to cut the widened grooves at each corner perfectly. I do not have access to a CNC system and I think you cut yours on CNC if I remember correctly?

I always said I was going to copy your handles Richard - I think they are inspired!

I'm not criticising your reasoning for making the choice you've made. It looks like it's going to work for you, and that's the key, really. Yes, the tambour's groove in Torpedore was cut on a CNC machine from a CAD drawing, so I just took advantage of technology available to me at the time. In earlier cabinets with tambours that I've made, that technology wasn't available, so I did what I suggested in my earlier post to open up the groove at turns. An example of that methodology was used in the piece below. The snap is a repeat of the image I posted on the second page of this thread, shown here again to save you scrolling back to that page for it.

I appreciate the inspired compliment, by the way. In my mind when I came up with that idea it just seemed to be a way of providing access to the cabinet interior without being clunky, avoided using visible metallic hardware, and had curves that picked up and complemented curves elsewhere in the cabinet, specifically the curve or sweep of the legs. I recall when I devised that solution I was inspired in part by an image of sand dunes in a desert when the sun is low in the sky - upward sweeps and black sharply delineated shadows, something like that, anyway. I hope that isn't coming across as all precious and poncey because it didn't feel like that when I came up with the idea - it just seemed like it would work, and suited the overall look. Slainte.

 

[gasman]

...my weekly update... and good progress but every time I think I have solved a problem something else comes along to cloud the pathway. A little frustrating but that's what happens when you make it up as you go along I guess.
I finished filing the ends of all the staves - here is a close up

Then stained and hardwaxoiled the fronts of all the staves

I carefully removed the central bit of the rear of the top and bottom of the cabinet and made a replacement fitted with wooden plugs so I will be able to insert or remove the tambours

I oiled the cabinet top and bottom

I bought a metre of black linen to attach the tambours to and constructed to pairs of parallel batons to contain the staves whilst the tambour was glued up

I used TB3 to glue the staves on to the linen - in retrospect this might have been a mistake we will see...
...but anyway I put it into the vacuum bag for an hour

When they were both done, I could see how they looked for the first time sitting in the groove of the bottom of the cabinet

Finally whilst the glue was hardening and oil was drying I started thinking about the drawer
I found some nice sycamore for the drawer front and mocked up a recessed handle

So, although progress has been made, I have new / different problems as follows:
1. The linen is quite un-stretchy and I think it may even have shrunk slightly as the glue dried so that the tambour will not lie perfectly flat but only at the end which will be the rear of each tambour. Don't understand how this has happened but I may even need to take a tiny bit of the sides of one or two of the staves which will be tricky but not too awful. I do have to take away one or two of these staves as otherwise the doors will not open far enough
2. There is glue on some of the tongues of the staves which mean they don't slide very well at the moment. Don't think this is too panicky yet just needs scraping / filing / sanding off. Then they need waxing
3. I cannot quite decide whether to attach the legs directly to the bottom of the cabinet or whether to put a spacer of some sort in so that it looks like the cabinet is floating. Think the top needs to be finished to make this decision
4. I want glass shelves above the drawer which gasses will sit on and want to put LED lights inside to illuminate the shelves so I need to make these unobtrusive - I wonder if I should have thought of this a long time before now!
Hey ho. Cheers Mark

 

[Sgian Dubh]

Normally attachment of the cloth to the staves is accomplished simply by passing a warm iron over the (PVA) glued cloth, see below. I wonder if the vac bag was the cause of the cupping? Hopefully that cupping won't be a source of sticky or overly stiff tambour movement. Good progress though, by the look of it. Slainte.

 

[Inspector]

The cabinet is going to look good.

There are many ways to glue the tambours to the canvas. I recall clamping all the tambours together in a frame. Quickly spreading a thin layer of white glue on the slats. Laying the canvas on, stroking it flat with my hand and placing a sheet of plywood on top, holding it down with a few bricks or some such weight. I remember watching my father repairing an old roll top and he spread the canvas out, took each slat and spread some glue on it, placed it on the canvas one at a time. Can't remember if he put any weight on it. It seams to work best if you don't stretch the canvas real tight.

Pete

 

[recipio]

Why linen and not canvas ? Is it an established technique ? Rounding the tenons is a good idea, do they run freely in the radiused groove .? I have seen some American designs use a dowel in the ends of the slats.

 

[gasman]

They did run freely before I glued it up. I need a couple of hours to work out the cause of the friction. I think it will be fine. However I am going on holiday tomorrow for 10 days so not going to get anything done about it until I get back

 

[MARK.B.]

That veneer is something special hurry back from your holiday,your local church would like their lead back as soon as you have finished with it

 

[gasman]

After two weeks break I returned with renewed gusto to get this thing finished.
First I had to decide whether to install lights which I originally wanted inside - the central part of the cabinet will have glass shelves and I wanted lighting somehow in that which would come on automatically when you opened the tambour doors.... I eventually found these on Amazon which seemed to do exactly what I wanted Motion Sensor LED Strip Lights, 5V LED Light Strip Battery Operated, LED Lights with Automatic Shut Off Timer, 5050 Music Sync Color Changing, USB RGB Bias Lights for Bed, Stairs, Cabinet : Amazon.co.uk
You can just cut them to size - so after a bit of thinking I realised that I could have the motion sensor on the underside off the top inside the central compartment, then mount the battery pack and rout a channel down the back to contain the cable.
Here are the lights cut down to size. You can choose from 100s of colours

I carefully routed a channel in the top of the cabinet as shown below to take the cables such that the motion sensor was at the right place own the underside of the top

Then routed a channel for the cable to go down the back

Then I had to cut a channel in the base for the USB connector too go through

Finally I made a mechanism of holding the battery pack on the underside of the base

I cut a thin piece of maple to cover the routed channel in the back

It ended up working very well - will share a video at the end showing how the lights come on fine when you open the tambour
This was quite a commitment step as there was not much going back once I started on this part - and the lights will eventually be sealed into the top when it is glued on so it had to be right
I had ummed and arred about whether to mount the cabinet straight onto the base or whether to raise it by 10mm so that it looked like it was floating
After some trial and error thought it looked better floating so I cut some 10mm dowels in walnut using my dowel plate and then drilled holes in the base and used centre points to mark the corresponding hole in the underside of the cabinet
Here is a photo with the whole thing dry-assembled showing the gap

More later
Cheers Mark

 

[gasman]

All was not so rosy however...
The tambours did not slide well enough... which was somewhat dispiriting
The problem was racking when you tried to close the right hand one - which was the one which had the asymmetric handle right at the top - so I thought the simplest solution would be to remake that with the handle lower so that when you pulled on it, the force was from the middle of the tambour rather than the top. Nice idea but it didn't solve the problem so I wondered whether it was because I had used linen rather than canvas.
In the end I don't think it was that but I think I had made a mistake in glueing each slat to the linen individually rather than just rolling all the slats together with glue so that glue went on the whole back surface. The way I had done it there was some of the back surface of the slats not glued to the linen which caused the racking.
This was frustrating but I quickly realised my only option was to redo the tambours - -t was easier than I feared. The linen pulled off and the glue residue came off easily with a scraper - then re-did it using canvas and spending the glue over all the tambours together and then it worked fine
I don't have any photos of this bit - these were dark days!
But here it is with the new fangled tambours and looking much better
So I was on the finishing straight
I glued the top to the cabinet - proper commitment move as that seals in the lights forever

The only things left to do are to order and mount the glass shelves and then fit it with whisky

 

[Hornbeam]

A stunning piece of furniture and one of the best / most thorough and enjoyable write ups I have read.
Fantastic!

 

[recipio]

Great piece of work, well done. Now I know where my next TV is going...........

 

[Sgian Dubh]

The end result is very impressive. Well done. Slainte.

 

[Cabinetman]

Yes, very good, and it’s the reworking it till it’s right that is impressive as well.
Love the top.

 

[MARK.B.]

That is very very nice indeed Now about that lead