Workbench Tops

[Neomorph]

I was just working out a levelling jig plan for reducing thin material (what I'm aiming at is creating 1mm thick glazing plastic out of 3mm to create shims) when I had a thought about what someone else here said about MDF.

Currently my temporary workbench top is laminated MDF (2x18mm) and I was going to use the levelling jig in the future to re-level it when it gets dinged up. Obviously this isn't correct after finding out that MDF has a hard outer layer and a "fluffier" inner layer.

So what's the solution? Some people here have mentioned using plywood. Is this the correct way to go? Add a Plywood top to my 36mm of MDF? What thickness would you suggest? I've got to get this sorted as in a few weeks time as my winter "pain barrier" is going to drop and I can finally get on and do stuff I've been waiting to do in my shed (namely clearing out the rubbish and finally getting around to start building my workshop).

So what do you guys suggest?

 

[Newbie_Neil]

Hi John

Why not use hardboard? It wears pretty well and when you have to replace it, it's as cheap as chips.

Cheers
Neil

 

[PowerTool]

I've just made a workbench for my chopsaws - went for 18mm ply,topped with hardboard as a replaceable layer (99p for 4'x2' )

Andrew

 

[Neomorph]

This may be a silly question but how do you go about cutting the dog holes so the match the ones in the bench.

I think I'm going to luck out as I have round holes in mine so I can mark out roughly the center of the holes and then use a router edge trimming bit to make them match perfectly. But what happens when people use square dog holes. You cant use a trimming bit for that... hmmm well maybe toget it roughly done and then jigsaw the corners perhaps?

It's amazing how one problem leads onto others isn't it? :roll:

 

[Scrit]

Why are you trying to reduce the thickness of packing pieces when they're available in various thicknesses or wedged?

I'd agree with the hardboard suggestion as that's what one of my benches is done with, although 3.2mm MDF gives you twice the life as it can be flipped over and the other face used. Don't have bench dog holes in mine, but I reckon they could easily be drilled in situ, routed out (then finished with a sharp chisel if they were square).

Scrit

 

[Paul Chapman]

Or a sharp chisel - you don't have to use power tools for everything.

Paul

 

[Scrit]

If you pre-drill it it's a lot easier to chisel out than trying to chisel blind (just like mortising) - it also helps keep your chisels sharp. Running a laminate trimmer round is quick and easy on larger openings but possibly overkill here, although I'd use it if the dog holes were round as you can't do round dog holes with a chisel. In fact I sometimes get a bit of stick because I still carry a brace and bit set in my everyday "site" toolkit, but I still find it fantastically useful for many tasks

Scrit

 

[Neomorph]

Why are you trying to reduce the thickness of packing pieces when they're available in various thicknesses or wedged?
(snip)
Scrit

Errr... Don't understand.... I'm not trying to reduce anything... I'm talking about when the surface gets dinged sometime in the future and I want to true the surface up again.

Flipping over doesn't help either if the side you are flipping over isn't level any more either. It could end up as a rocking horse top :wink:

 

[Scrit]

Flipping over doesn't help either if the side you are flipping over isn't level any more either. It could end up as a rocking horse top :wink:

Got it! In which case I suggest a belt sander and a light touch.... To pack-up beneath why not consider something like trowelling mastic, although if you start with a level top and skin with hardboard you shouldn't need it.

Scrit

 

[Neomorph]

But you still wouln'd have a perfectly level top unless you are a master at using the things (which I am definately not).

The way I was going to flatten the top was this technique which would give perfect results every time. All you have to do is level the two side support planks and then the router and sled does the works for you. Obviously this couldn't be used if the top was MDF (as it would go through to the fluffier middle bit) or hardboard either. I probably will go with a plywood throwaway top as it's the simplest method.

 

[LyNx]

am i missing something here, but why would you want to flatten a 36mm MDF top. Surely it's flat enough for 99% of the work we all do.

Not matter how flat it is, is going to deform if the carcass supporting it, or the floor is not flat

Andy

 

[Neomorph]

am i missing something here, but why would you want to flatten a 36mm MDF top. Surely it's flat enough for 99% of the work we all do.

Not matter how flat it is, is going to deform if the carcass supporting it, or the floor is not flat

Andy

Yup... workbench top is flat to start with. It's not now that is the problem it's after you start working projects on it... then you accidentally drill into it... take a chunk out with a chisel... get glue on it... oops, the router was set too deep and you now have a channel in it... and so after numerous projects your perfectly flat workbench is no longer flat anymore and as I will be using it to assemble as well it becomes crucial that it be as flat as possible.

Hence having a replacable top is better than having to go about resurfacing the top every so often.

 

[LyNx]

Got Ya!!

Why not just replace the top section of 18mm MDF, flip it over. Then, when that sheet is shagged, use the bottom one.

Or be more careful with your drilling and routering :wink:

Andy

 

[Colin C]

Also when chiseling, you could try a cutting mat
You can get them from pound shops for a £1 , I have had one for about 6 years.

 

[Scrit]

I'm probably the worst person in the world on bench tops. I pin and/or glue temporary jigs onto them, drill into to them (by accident, I might add), gouge them with chisels, etc. But to flatten them it's either oput with the woodfiller and a quick blast with the belt sander or throw away the top and replace it. After all a sacrificial hardboard afcing is all of £1.50 (or even less when the timber merchant delivers me a couple of pieces as protection on veneered MDF)

Scrit

 

[Chris Knight]

IIWY, I would try and separate assembly tasks and bench work. Build a nice flat torsion box assembly table and use the bench for other stuff, then you don't have to worry as much about overall flatness. Of course this depends on having enough space..

 

[Scrit]

I do have a couple of KD assembly tables (trestles and torsion box tops), but at times one of my benches (the older cheaper one) still get the cobbled-up jig treatment, mainly because I wouldn't do that to the assembly tables....... Maybe I need another bench (and another 200 ft sq to accommodate it!)

Scrit

 

[Paul Chapman]

Neomorph,

Another possible idea, if you have a Workmate-type bench, is to make up one or more bench tops by gluing together two sheets of 18mm MDF, lipping the edges with softwood to protect them. Screw a batten on one side so that you can clamp the top in the Workmate.

I have made up two of these in different sizes - one is about 3ft x 2 ft, the other about 26" x 20". I have drilled three rows of holes in the tops in which I use Veritas Wonder dogs and Wonder pups and on the larger one I have fitted a small vice on one end.

The tops are protected by wax polishing. This also makes it easy to get dried glue off.

I find them very useful for clamping up or other jobs when my normal bench is being used for other things. I made them a few years ago and they have remained flat. When not in use they stand against a wall in my garage not taking up much space.

Hope this is of some help.

Paul

 

[Neomorph]

IIWY, I would try and separate assembly tasks and bench work. Build a nice flat torsion box assembly table and use the bench for other stuff, then you don't have to worry as much about overall flatness. Of course this depends on having enough space..

Yeah space is a problem... I have a 10'x6' shed and my kitchen is even smaller.

If the weather is good I do tend to do assembly work on the drive with a couple of sawhorses and a sheet of MDF on them but it's awkward as my drive is on a slope. It's so bad that the one time my girlfriend got up early to go to work and went to go out the back door... she came back and went mad at me for parking so close to the door... I told her "Don't be daft" and then took a look and the bumper of my car was around six inches away from the glass. I hadn't put the hand brake on but had left it in gear (if I can remember correctly) and during the night had slowly rolled down the drive.

One thing that may help now is that I built an almost level deck next to the flat. This means I could make some sawhorses that could make a properly flat assembly table which should help.

Another thing that may help is that I'm thinking of building a carport next to my shed. I could then use the drive for assembly when the weather is bad as well.