using sheet versus timber for desk top

[edwardr]

Hi,

I'm making a desk, and after asking about how to do a drop leaf I ended up rethinking the existing plan of using 12/18mm mdf for the desk top and leaf.

I'm now looking at either 18mm ply (hardwood? birch?) *or* maybe using redwood pine planed all round timber. If I use timber then I they tend to be 144mm wide, which means I'll
have to join timbers to make the desk deep enough, and also the lead will need to be made of multiple timbers.

As a beginner is it worth using timbers and doing this or should I just stick to ply sheet that I can cut to size?

The only issue I see with hardwood ply is that it can be crappy quality, and I plan on rounding over / coving the rule joint on the leaf.

 

[edwardr]

Am I right in thinking I would use biscuit joints if I go down the timber route?

 

[Mar_mite]

When gluing two boards together like that, the buiscuits are more for alignment. You don't need them.

 

[rafezetter]

If you are not familiar with PAR and it's limitations / realities - read on. If you are then ignore most of the below

Regarding the plywood you can get very high grade sheets, including those guaranteed void free, but they will cost as well. It really depends on your budget / project time factor tbh. Having said that, the PAR timber might initially seem the cheaper option but may not be, as there's more things to consider:

- PAR is a misnomer, it simply means it's not rough sawn, but it DOES NOT ensure it's straight; has sides parallel to each other or that it will remain that way. Getting it from a proper timber merchant can help but it's still NOT guaranteed.
- is it dry enough to remain stable / straight / flat / true. Rarely is timber stored in a "ready to be used indoors" state, and will often need weeks of acclimitising in a similar environment to where it will end up, otherwise your carefully cut joints can all open up or the timber shake / twist.
- only unless you go through a large pile will you get timber with growth ring directions that can help you with the above, as long as you follow several rules, explained elsewhere.
- time taken dressing up (edge jointing) them, time taken to glue-up pieces large enough for your sizes, and then dressing them again to suit. (do you have a plane suitable for planing a whole desktop size sheet of glued up timber? The chances of you making a glue up with PAR that's perfect for your needs, with no dressing required are slim at best, no offense to your skills meant, but from what I've seen on posts here nowadays PAR quality leaves a lot to be desired.)

The plywood will be a simple matter of cut as needed and assemble. If the look of the ply on the leaf join is a big issue however then timber is one option (I'm assuming it's going to be left au naturel), the other being plywood for speed, then veneer the plywood cut edges, and fudge the leaf joint as best you can.

I know which way I'd choose being also a fellow beginner, even though I have the necessary planes etc to do the PAR dressing - it's WORK, even for a skilled planer.

 

[StevieB]

As a beginner, I would advise veneered ply or mdf and to dress the edges with solid timber. As stated above, solid timber can take a lot more effort and satisfaction is not guaranteed. Use of Ply/mdf also avoids considering movement due to moisture content. There is some surprisingly high end furniture that uses veneered panels so don't think of it as an easy route or a cop out!

Steve

 

[jdeacon]

As a beginner myself I recently experimented with glueing up PAR redwood for shelf and rack projects. It wasn't very successful.

I'd done a couple of projects with some fairly decent ply and a little project (in preparation for a bigger one) in birch ply. They worked fine. I'd done a couple of tablesaw sleds with MDF as well - no problems. But having seen loads of videos with people glueing up boards and looking at the price of narrow boards versus wide boards, I thought I'd see how it went. I don't have a jointer or a thickness planer (or a hand plane).

Despite choosing the straightest boards at my very understanding timber merchant, the cupping and bowing and twisting was quite noticeable during final assembly. The 4 x 3/4" were way worse than the 4 x 1"; when I realized how bad the 3/4" was, I didn't have the option of pocket holes - they don't work so well on a finished thickness of 15mm. Getting a good edge was OK as I have a table saw and a router table, but if^H^H when I go this route again, I'll be thinking about getting a jointer or a good hand plane.

They don't look too bad when full of shoes and books, but I shan't be surprised if there's a sharp noise and a side springs away from its shelves.

 

[Ian down london way]

I think it depends on whether you want a table, or a project.

Be clear in your mind about that.

 

[edwardr]

Thanks for all the helpful replies. I think I will source some quality ply. I like ply (as in, i like the look of it, and how it looks when routed). I guess I've only ever used rubbish ply, which is probably the trouble!

 

[AndyT]

Another alternative worth considering for a project like your desk is the glued up 'pine boards' sold in the diy sheds. They have the advantage that you can shape edges and use screws like you could if you joined your own boards, but you can buy big pieces which will be pretty flat.
It does depend what quality is on offer (I've not bought any for years) and what you want your desk to look like.

 

[RobinBHM]

There are merchants on ebay selling laminated pine board which will work fine for such a project. Its available in 18mm and 28mm (from memory!).

if you prefer the idea of plywood, I would go for birch ply but bear in mind there are likely to be butterfly knot repairs in 1 face and possibly 2. From a timber merchant I expect the ply will be BB grade with flaws on both faces.

If you go for veneered mdf, this would work fine for a fixed table top, lipped all round, but difficult for a drop leaf. The problem is that whilst you could lip the drop leaf edge, you will need a fairly wide lipping for allowing the drop leaf cove to be moulded in and the solid lipping will show up against the veneer. In furniture manufacture, such a top would be made by lipping the top before veneering.