Procrastinatus

Why talk about it now?

Mission: Workbench Resurfacing

Posted by aonomus on April 1, 2011

So you may have seen my old workbench that I built a few years ago in a variety of videos, blog posts, and other bits of projects documented here. I recently decided that in order to not only resume filming videos, but to increase the production value behind them and make them look better.


Image: before (left) and after (right)

Read on for a detailed, image heavy post about the entire process.

The reasoning behind embarking on such an intensive overhaul was because the old bench was too ugly to photograph or film video for anything due to stains, burns, and scratches. Additionally any video overlays and titles were always problematic since both white and black text tend to blend in far too well with wood grain, decreasing legibility of the overlays, a solid background of either white or black would prove to be more useful than just plain wood. The old bench had no water or chemical resistance, and was hard to clean as well.

The old bench was so bad, this is what I had to start with – burns, scrapes, stains (mostly activated carbon), etc:

Image: a well used workbench

So the tl,dr; version of my workbench resurfacing saga is as follows:

  • Sanded plywood bench
  • Filled and smoothed with 2 coats of drywall compound, sanding after each coat (note: dust hazard!)
  • Coat of primer paint
  • 3 Coats of flat black latex paint
  • 5 Coats of Minwax polycrylic finish

The longer version starts from here:

The first step was to prepare the surface, mostly by removing everything on the bench, cleaning it up, and sanding it down with coarse sandpaper. This is mostly to reduce the surface variation, and remove any built up crap on the surface to prepare it for refinishing.

The next step was to fill in the surface with drywall compound, CGC drywall compound is essentially a mix of silica, calcium sulfate, and other viscosity modifiers like ethylene glycol, etc. Filling in the plywood texture helped the overall finish be as smooth as possible as well. I chose drywall compound over other products like polyfilla for several reasons: cost, and inertness. Drywall compound is about $6-8 for a big tub large enough to finish several rooms of a house, while polyfilla is significantly more expensive. Additionally, drywall compound is mostly mineral based with some organic binders for good measure, while polyfilla contains more organics that could be heat sensitive or chemical sensitive. Polyfilla does have 2 main adavantages – strength (less brittle and crumbly), and shrinkage (lower amount of shrinkage upon drying. Regardless, 2 coats of drywall compound were used, with sanding after each coat. It should be noted that drywall compound is a significant inhalation hazard: it contains silica and other fine mineral particulate that can cause silicosis  and the dust released has the consistency of icing sugar, a respirator must be used.


Image: wonderful stuff, drywall mud (left), post sanding of first coat (right).

After 2 coats of drywall compound with sanding, the surface was fairly smooth and ready for painting. A single coat of primer was applied so that any additional paint applied ontop of the first layer would not soak into the highly porous drywall compound.

Image: primed and ready for paint!

At this point I also prepared the fiber-board backing for the workbench by measuring and cutting it to size. I purchased 2, 2’x4′ panels from Home Depot with a white coating already on them. I wanted to do the measuring and cutting before I had any finishing coats on the surface.

Image: measuring lab bench back-board.

Now, I used a roller to apply some flat black latex paint onto the primed surface, it took 3 coats to get satisfactory results.


Image: (left) ready for paint, (centre) wet paint, (right) dried paint.

After the paint layers had been applied, the top-coat was applied. I used Minwax Polycrylic as an alternative to polyurethane (or even water based polyurethane varinsh) since the weather outside does not allow me to use polyurethane or other coatings which have higher volatile organics or toxic chemicals.


Image: (left) wet polycrylic coating, (right) dry polycrylic coating

After the first polycrylic coating, the surface was gently sanded to enhance inter-layer adhesion, however this only revealed that the initial drywall compound layer wasn’t smooth enough as initially expected leaving holes in the black paint all over the place. A thorough sanding to roughen the polycrylic layer and one coat of black paint later, the surface was smooth and ready for more coats.


Image: (left) bench with imperfections in black paint layer, (right) new layer of black paint

Once I had the bench surface smoothed and painted black, the rest was just the repetitive task of painting more coats of the polycrylic coating onto the surface for 5 coats total (excluding the early failed coat).


Image: more polycrylic! More!

Once all the layers of polycrylic had been applied and given a solid day and a half to cure, the bench was pulled back from the wall, and the backboard attached. The back board was just thin fiberboard purchased from Home Depot, attached to some 1×4 lumber. In retrospect I may have wanted to attach the back board to a total of 4′ high, not just 2′ high, though any clean background is better than none.


Image: The resultant bench surface with back-board

All in all this took about $80 in materials (with enough leftover paint to do at least another 2-3 benches this size) and about 5 days involving odd hours of sleep to get the number of coats quickly.


Image: After so much work, the end result was worth it.

The real test will be over the next few weeks. I took a chance using this polycrylic coating not knowing how good its going to be. It will continue to harden over the next few weeks, increasing resistance to scratches, chips, etc, showing whether or not it is a suitable surface for a workbench. Worst case scenario every month or two I can sand and strip off a thin layer of the top 1-2 coats of polycrylic and apply an extra 5 coats in a weekend if it sustains significant damage with heavy use.

Oh, and mission complete.

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