On 3/7/2010 4:01 PM, graham wrote:
Wow, thanks for all the responses guys, you've been a great help.

I've taken on board the points of simplicity and sufficiency and will go
the build route. I can always change it later..

My plan now is a simple benchtop table, a box made of 3/4" birch ply
(because I have some), with webs from side to side to support the top
(ie. enable me to clamp the top down to it when I fail to make it
properly flat).

For the top I'm uncertain - I could use more birch ply, or go the MDF
route. Either way I'm uncertain of the laminating - surely wide areas
like this require a great deal of force to provide enough pressure on
the glue joint?
And with all that force (presumbaly via curved battens) it seems likely
that the panels will flex and then set non-flat?
Adding the Formica (UK trade name for phenolic sheet) ditto, and that's
not cheap stuff either - though I could always (not) add this later..
For starters I think I might just go with a single sheet of thick
mdf/ply - whatever the yard has in.

If you use 3/4" MDF that's usually pretty damn flat; if you glue two of them
together any warping will almost certainly be canceled out and the result will
be DAMN flat. Applying the laminate should be done with contact cement, and no
battens or undo force is required; just a rubber roller. Apply contact cement
to both surfaces (the MDF and the back side of the laminate) according to the
instructions on the product (usually you let it dry about 10 or 15 minutes);
the MDF will need a second coat because it's very absorbent. Lay a series of
long 1/4 dowels down on the MDF (if the cement is dry they won't stick) about
6" apart, then set the laminate down on the dowels (so the glued surfaces don't
meet; you have ONE chance to get the positioning right or you're screwed).
Once you have the laminate positioned correctly, pull out the center-most dowel
and push the laminate down towards the MDF surface with your rubber roller.
This will adhere the two together hard and fast, then you gradually work the
roller from the center towards each end, pulling another dowel out as needed;
this lets you get the laminate glued in place without trapping any air pockets
underneath. Be firm and thorough with the roller, making sure the laminate is
completely adhered before progressing further towards each end. Use the
appropriate router bit to trim the laminate flush.

The advantage of having a smooth surface such as laminate is that you can pass
the workpiece through the cut with little to no friction. Keep the laminate
clean and waxed, and you'll never have a workpiece grab or drag while you're
cutting it, which can be very frustrating and sometimes downright dangerous.

--
Any given amount of traffic flow, no matter how
sparse, will expand to fill all available lanes.
To reply, eat the taco.
http://www.flickr.com/photos/bbqboyee/