MDF Workbench top - best finish?

[JDW]

Having chosen MDF for my workbench top I'm now researching the best finish. I'm down to Hardwax oil, Danish Oil or Shellac. I'd appreciate any help with which one to go for.

PS, worth spending a few extra quid and getting MRMDF?

Cheers

Jim

 

[doctor Bob]

An MDF top is a poor choice in my opinion. if your going the use and replace root you are better of with raw chipboard.

 

[JDW]

Thanks Bob.

I'm going for MDF because it gives a smooth, fairly hard, stable and relatively heavy (when using 18+18mm) solution and you get a lot of surface area for your money.

Its major weakness is its propensity to readily soak up water based liquid.

I do know that with the appropriate finish the MDF will be well protected and give me a few years service - at 40 a sheet it certainly won't owe me anything when I'm finished with it.

I wouldn't use chipboard personally.

In fact, I've talked myself into MRMDF, I would just like help to decide on the finish.

 

[Terry - Somerset]

Given the choice I would go with ply as it is far more rigid than MDF which will sag unless well supported.

Could use MDF (9mm??) as a replaceable surface - in which case probably varnish which will soak in a provide some protection against liquid spills.

 

[JDW]

Thanks Terry, it will be braced so no chance of sag. I hear you about ply, I'm going to go 18mm mdf on 18mm ply.

I've got some hardwax oil and some poly so I'll run some tests.

Cheers

Jim

 

[doctor Bob]

The reason we use chipboard is you can abuse it, then unscrew and replace for peanuts, no more fretting about drilling holes through it of spillages etc. Our tops last about 3 months, then replace.

 

[robgul]

To answer the OP question - one of my benches is MDF (but edged all the way round the top) - I just gave it about 4 coats of cheap acrylic matt varnish from Screwfix - it repels any damp or chemicals - and the appearance doesn't matter too much.

 

[Jameshow]

Yeap poly varnish thinned.

 

[JDW]

Thanks James and Rob. I'm going to edge mine as well. Poly you say... guess you can't go wrong with poly. Did you bother with MRMDF or standard?

 

[Oscar43634]

I used Osmo Polyx on mine (MRMDF) as I already had some left; it's doing pretty well after nearly a year.

 

[JDW]

Thanks Oscar

I have some Osmo Polyx too. I'll test the Osmo and some poly.

Definitely going MRMDF

Cheers

Jim

 

[robgul]

Thanks James and Rob. I'm going to edge mine as well. Poly you say... guess you can't go wrong with poly. Did you bother with MRMDF or standard?

Just regular MDF - no point in spending more!

 

[Mike.R]

I use 25mm moisture resistant MDF for assembly bench tops, finished with thinned down polyurethane or Osmo or anything like that I have hanging around, just so the glue pops off. It's important not to overthink these things... although thinking about it, I wouldn't use chipboard.

For anything.

 

[Chris Hawkins]

I’ve been using 18mm MDF for my bench top for many years. It’s flat and stable and absolutely perfect. Simply finished with Rustins MDF sealer. It’s MFT'd with the Parf Guide System. I tend to replace it every 2 or 3 years or so when glue spills and general damage dictates. Always used cheap B&Q MDF but next one which is due shortly will be Medite MR. May even switch to Valhcromat if the price is not nuts. I find regular use of a chisel plane and occasional very light pass with RO sander keeps it tip top.

 

[JDW]

Thanks fellas.

Chris - what do you use to support your 18mm mdf sheet? Ply, solid battens?

 

[Jonm]

PS, worth spending a few extra quid and getting MRMDF?

I have an mdf workbench, 2.4 metres by 0.9 metres located in the centre of my garage. Has to be quickly and easily dismantle-able and storable so on trestles. Two longitudinal support timbers About 700mm apart so 100mm overhang down the sides. Top in two parts clamped and dowelled. Single thickness of 18mm moisture resistant mdf. I did not treat it and after 18 months it is fine. Still flat, no twisting, sagging, blowing or anything else, a bit stained in places.

I would definately recommend moisture resistant and if I was using it for a proper bench I would treat the underside of it the same as the top, just to try and keep moisture content same, top and bottom.

 

[Padster]

I used 25mm MRMDF and didn't bother with a finish, been great and stood up to the abuse I give it....

Padster

 

[TomB]

I made mine out of three layers of 25 mm bog standard MDF edged with beech. Three coats of polyurethane to seal it (top and bottom) with the first two coats thinned with white spirit.

Not the prettiest thing in the world but it didn’t cost much and it’s worked really well. No sagging in the middle. I added some thin CA glue to the inside of the dog holes and they’re holding up fine so far even with holdfasts.

 

[Puggers]

Hi Jim,

I’ve used 9mm MRMDF on top of 18mm MRMDF and applied Rustins MDF sealer followed by Screwfix’s no nonsense trade varnish. It’s stood some beating and the 9mm can be easily replaced when at the end of its life.

Mine’s mounted on C16 lengths and cross braces every 18 inches. Might be overkill but it works for me.

 

[Chris Hawkins]

Thanks fellas.

Chris - what do you use to support your 18mm mdf sheet? Ply, solid battens?

The bench is 1600 x 800mm. The MDF sits on a frame of the same size with 3 cross batons. I regret that design because the batons interfere with the orientation of the hold down clamps I use frequently with the MFT holes. When I change the top I’m going to remove the batons and replace with a couple of vertical posts which will simply sit on the shelf below (probably attached to the shelf with a domino or dowel). I’ve attached some photos if that helps.