Thread: WIP - Groggy's Workbench

Great job Groggy, well done mate.

Finally finished the rebuild of the WOB. Col gave me some adjustable feet which worked a treat, where the outfeed bench is the floor is very uneven. The top is now screwed down and the bench is a mm or two below the tablesaw so there will be no snags when feeding panels out.

I've got my eye on some liquid amber for the bench top, maybe, we'll see.

I've been on again and off again about the timber to use for the top. I have some liquid amber that would do the job but after talking to Wongo and a few others I have decided to use something else. Liquid Amber tends to split and is reasonably soft. Whilst a soft timber is not bad (it doesn't damage the workpiece) LA is just a bit too soft.

So, now I have to source a new top. I am thinking of some hardboard topped mdf, surrounded by Celery Top pine as skirting as one option. Any ideas folks?

I've had Oak and Beech benches which were brilliant due to the sheer mass of them, but I've also built a few benches with three or four layers of MDF and I realoly like them too. There's obviously no planing and flattening involved with MDF and once sealed, appears to withstand regular abuse and still looks good.

Thanks WW. The main reservation I have about mdf is the distance it has to span (nearly 1800mm). I am concerned that a slab of mdf 1800x500 will sag over time; even though the sagulator says it will be negligible. Putting stiffeners underneath is not something I want to do either as it may interfere with holdfasts, vices and clamps.

My previous MDF-topped benches utilised the full length of the 2.4m sheets and I never had a sagging problem (with a 600 mm width). My current bench is only about 1500mm long and is full of vice bolt holes and dog holes and hasn't suffered in the slightest.

Originally Posted by Woodwould

My previous MDF-topped benches utilised the full length of the 2.4m sheets and I never had a sagging problem (with a 600 mm width). My current bench is only about 1500mm long and is full of vice bolt holes and dog holes and hasn't suffered in the slightest.

Hmm, couple of questions if you don't mind WW:

• What thickness mdf?
• Was it multi layered and how many?
• Did it have any support underneath?
• Was it glued together or screwed?
• Did it have support at the sides?

My current bench is the one in this thread. There are three layers of 18mm MDF glued together. The first two layers were layed on level sawhorses and glued and screwed together. The screws were later removed and the third layer was glued and screwed to the previous two.
The laminated slab sits directly on the legs and end supports and is held down with screws inserted through the underside of the end supports. The pine edging is screwed to the legs, the end supports and the MDF slab. There are no other supports. I can beat the living suitcase out of anything placed on the centre of the bench without any springyness resulting. If I were to change anything, I would make the front facia, at least, out of hardwood of some description (not Vic Ash - hideous stuff!) in stead of the clear pine I did use.

Originally Posted by Woodwould

There's obviously no planing and flattening involved with MDF and once sealed...

I disagree. I have a 1200mm span (3 x 18mm MDF, glued) for my primary bench and I've had to flatten it twice over three years. The entire top cupped and needed almost 4mm removed from the outside edges to get it flat again. I was fortunate the last time that Helmuts D2 woody plane irons held up better that the standard Stanley irons, which went blunt after only a few passes.

Moreover, my router table which is 450 x 600 x 18mm x 2 layers, glued, had to be flatten after one year, it also cupped. This was sealed with Estapol the day after the peices were glued together and edged with hardwood.

I wouldn't trust MDF any more than any other timber product.

Fair enough. There are always different experiences.

Groggy, to fight MDF sag would a torsion box fit within your design?

For all other sag, liposuction works.

Originally Posted by Waldo

Groggy, to fight MDF sag would a torsion box fit within your design?

For all other sag, liposuction works.

A word of caution: I put my faith in the rigidity of a TB for my router table top. For smoothness and wear, I then added a melamine chipboard top surface, glued, and screwed round perimeter and void.

Recently I was having some problems, and while checking whether the insert was flat/warped, discovered that the whole top was slightly domed.

Not sure whether this is due to differential warping with humidity changes, or whether my original TB was flawed, but I am reasonably sure I checked that after I completed the TB. I will recheck in light of our recent (very) humid Sydney weather, and see if it has got worse.

regards

Waldo, a TB would provide the rigidity but not the mass. I also intend to have a number of dog holes scattered around and this would be tricky with a TB design. The final issue is with attaching the legs, they will be flush with the skirts and held by drawbored tenons so a TB would not really suit.

I finally found some timber for the top. I found some beaten up timbers that had been in use in an old warehouse that was recently demolished. There are 6 posts 100x145x3000.

Some of the ends are a bit rotten and there are a lot of nails to take out. I have de-nailed four of the posts so far and have removed about 50 nails. I plan to trim bits off the ends then 'mend' the nail holes by making some dominos out of the offcut materials then using the Domino to cut patches I can plug the dominos into. Then I will just trim them off and plane flush. Since this will be the repair method for future holes I figure I may as well start now.

Finished size for the top should be approximately 600x140x2400.