Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

In article , says...
Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

Well, obviously to an extent that would depend on what you put on it -
but it will sag quite a bit over time.

If you're cutting it to 700, cut some strips off the offcuts and make a
box-girder to run along the front. It only need be a few inches deep to
add considerable rigidity. Failing that, a trip to your local steelyard
will get you a 7m bit of angleiron for a few quid. Take your own
hacksaw, though.

--
Skipweasel - never knowingly understood.

On Mar 28, 8:28*pm, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends?

Yes. Mostly though MDF might not flex immediately or break, but it
will cetainly sag over time. You do need to support beneath this. You
don't need to support right at the front edge though - you can set it
6" - 9" back, especially if you also support at the ends and bring
that bearer right to the front edge.

On 28/03/2011 20:28, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.


You need - the sagulator!

http://www.finewoodworking.com/Skill....aspx?id=28101

--
Dave - The Medway Handyman www.medwayhandyman.co.uk

Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I need
a long bench with no legs at the front. I will be cutting it to 700 width.

Short answer, yes. However if you made a box structure then it would be
much more rigid.

On Mon, 28 Mar 2011 20:28:43 +0100, Count de Monet wrote:

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

That'll be damn heavy bit of MDF... Like the skipweasel says just put
something along the front, doesn't have to be a box section just a
bit of 100x20 or similar, broad face vertical, fixed to the legs at
each end. With 2400 length I'd also stick a couple running front to
back to stop it wibbling or fix it to the top somehow along it's
length.

--
Cheers
Dave.

On 28/03/2011 22:04, Dave Liquorice wrote:
On Mon, 28 Mar 2011 20:28:43 +0100, Count de Monet wrote:

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

That'll be damn heavy bit of MDF... Like the skipweasel says just put
something along the front, doesn't have to be a box section just a
bit of 100x20 or similar, broad face vertical, fixed to the legs at
each end. With 2400 length I'd also stick a couple running front to
back to stop it wibbling or fix it to the top somehow along it's
length.

or a length of anle iron

Malcolm

On 28/03/2011 20:28, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

I will be supporting the MDF on three sides with battens attached to the
walls.

Would the idea below be OK for stopping sag at the front?

http://tinyurl.com/4fue87e

On Mar 28, 8:28*pm, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

Definitely would flex. Why not get some kitchen work surface?

On 28/03/2011 23:10, Malcolm wrote:
On 28/03/2011 22:04, Dave Liquorice wrote:
On Mon, 28 Mar 2011 20:28:43 +0100, Count de Monet wrote:

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

That'll be damn heavy bit of MDF... Like the skipweasel says just put
something along the front, doesn't have to be a box section just a
bit of 100x20 or similar, broad face vertical, fixed to the legs at
each end. With 2400 length I'd also stick a couple running front to
back to stop it wibbling or fix it to the top somehow along it's
length.

or a length of anle iron

Putting the angle iron with the vertical bit up would both keep the
underside of the front edge of the board clear and protect the front edge.

Personally, having had to move 25mm thick MDF before, I would fabricate
a frame entirely from steel or aluminium, bolt that to the walls and use
a thinner top.

Colin Bignell

On Mar 28, 9:28*pm, The Medway Handyman
wrote:
On 28/03/2011 20:28, Count de Monet wrote:

Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

You need - the sagulator!

http://www.finewoodworking.com/Skill...lsAndTechnique...

Yes, that'll tell you how much each option will sag. The other issue
with MDF is it doesnt tolerate drips on mugs at all well. And its
somewhat weak too. I just stay away from the stuff, it has little
going for it.


NT

On Mar 28, 8:28*pm, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends?

Yes. Why MDF?

If it has to be MDF (for the surface finish?), use something a lot
thinner and make up a box structure with lots of internal ribs. Think
of how a hollow internal door is made.

MBQ

On Mar 29, 8:12*am, harry wrote:
On Mar 28, 8:28*pm, Count de Monet wrote:

Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

Definitely would flex. Why not get some kitchen work surface?

Because that may well sag over time, depending what it's supporting.

MBQ

On Mon, 28 Mar 2011 20:28:43 +0100, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

When I made my bench I used a 2400x600 sheet of contiboard with mock
lightish veneer on both sides. I used 49x74mm (or 2 by 3) timber for
the legs (with cross-pieces), a kicker rail at the bottom and two
struts along the front and back to support the length.

Total BoM was 1 sheet of contiboard, 5 2400mm lengths of timber
(3 for the lengthwise supports & kicker, 1 at each end for the
legs) By cutting the lengthwise supports short, I got the right
sized lengths for the cross-pieces on the top + bottom of the legs,
so the height is just right for sitting at the bench.

6 years later it's still going strong - despite 2 CRTs, a printer
and couple of 'puters on it. No bowing or sagging - wish I could
say the same for me!

Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

Has anyone suggested some decent 12mm ply with a piece of 100 x 25
softwood fastened under the front?

--
Tciao for Now!

John.

On Mon, 28 Mar 2011 20:28:43 +0100, Count de Monet wrote:

Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.


I used blockboard (& intended to edge it with 18mm wide pine where it
mattered but never got the round tuit). It's a heck of a lot lighter than
MDF and plenty strong enough for a computer desk if you just think about
where the support is needed. This desk is about 800mm wide and I can
stand on it in the middle. No support along either the front or the back,
but there are 2 shelves with a solid back between them.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info
Filtering everything posted from googlegroups to kill spam.

"John Williamson" wrote in message
...
Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I need
a long bench with no legs at the front. I will be cutting it to 700
width.

Has anyone suggested some decent 12mm ply with a piece of 100 x 25
softwood fastened under the front?

--
I suggest 12mm ply with batten at the back and at the ends

Use a length of 75 x 50 at the front rebate the inside top edge to 25mm side
by 12mm deep rout or sand the outside top edge top a roll top profile

Set the ends of this into the end battens

Made one like this several years ago no discernable sag to date.

Has been used as a sewing machine/domestic overlocker bench as well as a
computer rebuild bench

regards

"Count de Monet" wrote in message
...
On 28/03/2011 20:28, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.

I will be supporting the MDF on three sides with battens attached to the
walls.

Would the idea below be OK for stopping sag at the front?

http://tinyurl.com/4fue87e

Hey, that's what I used for my bench! (8'x3' coated chipboard in about '85)

I think it did help it reducing sag, but my bench was for electronics,
nothing heavy. And it could still get in the way, if that's the idea of no
legs.

--
Bartc

In message , The Medway Handyman
writes
On 28/03/2011 20:28, Count de Monet wrote:
Thinking of using MDF for my computer build work bench.

Would 2400 x 25mm MDF flex if only supported at the back and ends? I
need a long bench with no legs at the front. I will be cutting it to 700
width.


You need - the sagulator!

http://www.finewoodworking.com/Skill...ndTechniquesAr
ticle.aspx?id=28101

Get a cheap fire door from Wickes (About£30, even cheaper from a skip).
Support each end on a couple of filing cabinets or hollow block piers.
You can stand on it and it won't sag.
--
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