Plywood advice

[novice1]

Hi all,

really struggling with thinking through a project;

Im building a bespoke dining table but am stuck on how to support it to stop it bowing. the design is a strange shape, but essentially i want to make this out of strips of plywood placed on end and stuck together, stacked if you will, so that all the plies will be on the top of the table. i have toyed with drilling holes through them all and slotting them on thick dowels and glueing them in place together, but worry that the weight will make it sink in the middle a little.

Could i cut grooves/ slots in all the strips so that they slot onto a supporting board underneath?

its going to be 2 metres square (ish)

What are your thoughts?

 

[Racers]

You could make the strips into an E shape thicker at the edges and a rib or ribs underneath to strengthen the top.

Sounds nice what ply are you using?

Pete

 

[sunnybob]

What depth of ply?

I would have thought dowels, offset from one piece to the next (5, 4, 5, 4 ) kind of thing.
Youre going to have to come up with something special for the top finish, ply when its edge on is very soft.

 

[WellsWood]

Hmm.. I'm going to be watching this with interest. It sounds like a great idea if executed well. Will you be documenting the build for us to see at all?

How thick is your top going to be? I imagine a 2m square slab will potentially flex quite a bit unless well supported - and a thick top of ply will be weigh a ton. There may also be an issue with flatness made this way, I have been working with Birch ply recently and found vaiations in thckness I did not expect. In your build, strips cut from boards without very consistant thickness may translate to cupping or undulations across the width - as any of the stips could potentially end up slightly wedge shaped. I wouldn't bother about grooving the underside (will weaken it), or threading onto dowels for alignment personally, just cramp them all up with cauls having applied a consistant glue layer with a roller and then be prepared for a serious sanding session.

I'd expect to use the sawdust from sanding mixed with adhesive/resin to fill any voids after the first sanding. I'd also expect it to drink large amounts of whatever finish I was going to apply as the top will be a minimum of 50% end grain. Could look terrific - i can't wait!

 

[pcb1962]

Youre going to have to come up with something special for the top finish, ply when its edge on is very soft.

A 2 part epoxy finish designed for boats works well on plywood edges. Not cheap, but then neither is decent plywood.

 

[custard]

It's a very on-trend idea

I haven't made anything like this yet but I'm floating the idea to potential clients, I hope I'll get a commission before too long and then I'll use that piece to sell the concept further.

Talking to furniture makers who have worked with laminated edge ply they all say the same thing, build times are slow and you need a strategy for dealing with the inevitable issues of filling voids and flattening off laminated panels. You can buy specialist Birch and Poplar ply from the Continent that's guaranteed void free, but it's two or three times more expensive than top grade Birch ply. The method also places a premium on your ability to work to very fine tolerances. Slight irregularities in solid wood furniture may seem charming, but with ply it either has to be to engineering levels of fit and finish or it just looks cheap and amateurish.

Total guess but I can see laminated edge ply really taking off. In the short term it would be like waney edged work and offer a bonanza for independent furniture makers. But unlike waney edged furniture, which is virtually inaccessible to large manufacturers because of the variation in the raw material, with this once there's a proven demand industry will be able to step in and produce this style of furniture far more efficiently than the small maker ever can. If that's right then it's a case of making hay while the sun shines!

 

[pcb1962]

not ply but OSB: http://www.ibuildit.ca/Woodworking Projects/osb-stool-1.html

 

[oakmitre]

If you type 'Threaded rod laminate table' into google images, could the rods be loctited at the ends and the final lamination be used like an end cap to hide it all ?

You could still use short dowels, like locator pins in each lamination as well.

 

[sunnybob]

Those pics that custard posted, i really like the curved stuff but that flat table is FUGLY.

 

[custard]

Just make the top 35 or 40mm thick with a decent apron rail all round and it won't sag. It'll be heavy but plenty rigid enough for a table. You can finesse the dimensions with the help of the sagulator,

http://www.woodbin.com/calcs/sagulator/

In terms of jointing the top together, if the strips have been accurately cut then you don't need anything except glue. You support the strips on bearers and you sight across the bearers like you would with winding sticks to ensure they're all co-planar. Maybe pop in the the odd biscuit here and there if you're nervous about it but that shouldn't really be necessary. Threaded rod or dowel is just adding complexity for no benefit.

No matter what you do inevitably there'll be some strips that are fractionally proud. No problem, a finely set hand plane will sort that out, or an orbital sander starting at 80 grit and working through to 240 grit would finish the job. Alternatively you could glue up the top in sections and pass each section through a planer/thicknesser if you don't mind your knives getting massacred!

I wouldn't overthink this job, it's really just about being meticulous when cutting the ply strips, gluing up, and filling the voids. It's more tedious than complicated.

Good luck!

 

[Adam9453]

I've also been toying with designs based on this for years, my preferred method would be to prepare one piece exactly to finished size, affix the next layer which is cut slightly oversize, then route the oversized piece using a pattern cutting bit riding on the first layer as the 'pattern'. This should produce a consistent result but would be slow going.
Interested to see how you get on with whichever method you choose

 

[skipdiver]

I recently went in a trendy bar and there was loads of this type stuff in there. It looked good and as custard says is very 'on trend' at the moment. There is some in my local McDonalds too, which has just had a re-vamp.

 

[davin]

I made some vases for Christmas presents. Only small but went down very well.
Was very easy to do. I simply cuts strips and pva glued together, then sanded and osmolised various colours.
I found that the ply face side to face side sets very quickly using pva. If I was to make a table top I would glue narrow strips together (maybe 300mm at a time), then clamp together to make a wider top.
Wasn't brave enough to put through my thicknesser ! A drum sander would be the answer.

 

[n0legs]

I used a load of 90mm kerto for stair treads, stood at the bottom they looked amazing end on.
They were a pipper to finish though.
If you could source some of that it would speed things up in construction.

 

[AndyT]

I remember seeing this table in the V&A. According to their website it's not on display at present, which is a pity. It's plywood, on edge, but the pieces were not all the same shape!

http://m.vam.ac.uk/collections/item/O12 ... en-jeroen/

 

[custard]

Glad you posted that Andy.

2005 was the absolute height of the "Studio Furniture" movement. It seemed like finally there was a viable business model for the very top echelon of independent furniture makers, spend a year or more making something genuinely amazing and then sell it for a six figure sum to a museum or a collector. But with the financial crash of 2007/8 that all came to a dead halt. I certainly don't make furniture at that level, but I know people who do, and they say the studio furniture market has never really recovered and the opportunities to sell pieces like the one you linked to is now just a fraction of what it once was.

 

[No skills]

I would do some test cuts with the ply you have chosen and see how much the bits/strips you cut off move or distort.

Tension in the ply may cause more movement than you expect, if you can work out an average then you can allow for making the strips a bit wider in width so the final glued up top can be flattened back to the required thickness.

I've played with laminating bits of marine ply and found the surface handplanes quite well (even with my limited handplane skills), never got round to trying to sand it tho.

 

[AndyT]

Glad you posted that Andy.

2005 was the absolute height of the "Studio Furniture" movement. It seemed like finally there was a viable business model for the very top echelon of independent furniture makers, spend a year or more making something genuinely amazing and then sell it for a six figure sum to a museum or a collector. But with the financial crash of 2007/8 that all came to a dead halt. I certainly don't make furniture at that level, but I know people who do, and they say the studio furniture market has never really recovered and the opportunities to sell pieces like the one you linked to is now just a fraction of what it once was.

That makes sense. My taste is generally for more traditional things, but that piece was such a blast - made of 'ordinary' birch ply, but in such a clever, imaginative way that it seems to stake out new ground to be explored. It was interesting watching how much the other visitors liked it - it was definitely 'oh wow' as people spotted it. Has it been influential?

 

[Jake]

2005 was the absolute height of the "Studio Furniture" movement. It seemed like finally there was a viable business model for the very top echelon of independent furniture makers, spend a year or more making something genuinely amazing and then sell it for a six figure sum to a museum or a collector. But with the financial crash of 2007/8 that all came to a dead halt.

There was a moment back then when design/craft objects more generally were beginning to shade into the fringes of the art market. Although the art market took a tumble in 2008 it came back very quickly helped by tiny returns on more traditional investment and ever present need for transportable/lock-up-able items of great value for those who have lots of sometimes shall we say smelly cash. But, I suspect those who had put money into design/craft objects pre 2008 found post-2008 that there was no liquidity and so desperately poor resale values (compared to art) when they wanted/needed to cash out. Illiquidity is a killer for "investors".

 

[rafezetter]

As Pete Maddex said - I've seen this done in numerous ways and the least obtrusive I've seen is to make every 10th slat, give or take, much deeper but shaped in a sort of "wave" pattern, so the ends are the same depth (or make a bit of a feature to suit taste) but they quickly curve past the knee point to full depth along the centre.

I have no idea of what's the minimum depth you can get away with, being ply it's not like wood whereby across the grain strength is significantly sronger, maybe another member might be able to throw some light on that bit?

There was a moment back then when design/craft objects more generally were beginning to shade into the fringes of the art market. Although the art market took a tumble in 2008 it came back very quickly helped by tiny returns on more traditional investment and ever present need for transportable/lock-up-able items of great value for those who have lots of sometimes shall we say smelly cash. But, I suspect those who had put money into design/craft objects pre 2008 found post-2008 that there was no liquidity and so desperately poor resale values (compared to art) when they wanted/needed to cash out. Illiquidity is a killer for "investors".

Lol dammit, I was going to see if I could find a friendly neighbourhood drug dealer, sorry, benevolent patron of the arts with a taste for art and wads of "smelly cash".