I wanted to build a worktop to be clamped into a workmate or folding workbench to provide a larger working area and as I had some spare 18mm MDF, 2×2″ and 2×3″ CLS I used them. MDF can and does warp so I framed the edges with the 2×3″ which I glued and clamped and then drove a few screws to hold in place. This will provide extra strength and also provide a surface to clamp against.
All that’s needed now is to run over the bench frame with a random orbital sander 180 grit to remove the pencil marks and to improve the finish. I will then wipe over the frame with Danish Oil to protect it – two coats with six hours between coats.
Finishing the Workbench MDF worktop
The MDF top and shelf was varnished with polyurethane oil based varnish thinned by 50% white spirit for the first coat, left to dry overnight and then 25% white spirit 75% varnish for the second coat. It was laid on thickly and let soak well into the board. The varnish is thinned to really get it to soak into the board, rather than a top film of varnish that may chip away. Then a final neat coat of varnish was applied. I wiped the surface with 240 grit sandpaper between coats to key the surface.
[picture of varnish and white spirit]
This will soak in well and provide a durable and resistant finish for the bench top. Alternatively Boiled Linseed Oil or Danish Oil could be wiped over and again let soak in well or a piece of hardboard could also be used as a sacrificial top and replaced as required.
Making a Workbench Part 1 is here, Part 3 here, completed (almost) picture here tools lists here and final finishing here.
I first started by marking up the long sides with four marks to provide a fixing point for the legs and marking four points on the shorted sides – 2 to attach to the sides and 2 to attach to the legs. I marked this up on a template to speed the process up, then piloted drilled and countersunk the holes.