Chessboard modification

I received a 30cm chessboard box that was in a slightly poor condition. I have a better box in better shape (pictured above) so this was an opportunity to modify the damaged one.

The set is nostalgic for me as I played with similar pieces a lot during my childhood and youth in the 1980s-1990s. I believe these sets and likely the design itself originated somewhere in what was then the Soviet Union, and come in numerous variants and varying build quality. I have no idea how typical these might have been over there.

I am especially fond of the bishops, with no distracting "mitre" or knobs on them.

Admittedly the board is a bit dense for playing, although it looks visually pleasing to me and given the history I'm hardwired to accept this as a normal chessboard.

A board with slightly larger squares could still come handy. The goal at first was to increase the size of the playing squares, but I also became quite interested in the surface treatment.

Half board removed. The amount of dust is spectacular.

The box is 300 x 300 sized, with the original borders it makes the effective play area about 280 x 280 with 35 x 35 mm squares.

To fit this more with my blog theme, I used a Commodore 64 BASIC loop to calculate the measures. So, without the borders the square size becomes 300/8=37.5

The box is slightly deeper than it is wide, so I used 151.5/4 to get the other square dimension for each half-board, which was 37.875. Although this kind of precision is somewhat pointless for my handiwork, it is important for adding up the cumulative measures.

Sanding away the existing squares was the most boring work stage, although the actual sanding likely didn't take much more than 30 minutes altogether. The staining and lacquer treatment requires the surface to be well finished, and I used 80, 120, 240 and 320 grit sanding paper to get there.


Woodstaining

The measure marks were made to all edges of the board, then I used a paper knife along a ruler to pull grooves across and along the plywood. This means that when I brush in the dye, it won't be absorbed over the square edges.

Carefully testing the board, the pieces don't touch the stained parts yet

Still, the brushwork needs to be careful. It was better to allow the liquid to flood towards the edge instead of trying to brush directly along the grooves. Firstly, the absorption effect is quite forceful, and secondly, the brush could also easily touch the other square which would be "goodbye, board" to me.

The cuts across need to be quite deep whereas the cuts along can be shallow.


Lacquer

After letting the staining dry overnight, I applied urethane alkyd lacquer on the surface. One layer of the lacquer was nearly enough to make the kind of smooth surface I looked for. After 24h drying I made a light in-between sanding with the 320 grit paper, wiped out the dust with a moist rag, waited a bit and added another layer.

But after half an hour I dared to test the whole set. (This is still without the lacquer)

Afterwards I'm quite happy with the surface. I did get those tiniest bubbles for both layers. This might be unacceptable in a continuous table surface, but with this kind of checkered board it is not too visible. If you look for them they are there.

Can the bubbles be avoided? It turns out I had not heeded the instructions: the first layer ought to be thinned by 20% and multiple thin layers would be better than 1-2 thick layers. Also, a proper brush might have helped reduce the "bubbles".

Comparing the new width squares with the old.

The paper knife technique has the weakness that the grooves will remain visible. More often than not paints and lacquers tend to highlight scratches, dirt and unevenness, than smooth them out. Still, I don't think these grooves are ugly.

An alternative approach might have been to make a new board layer entirely from plywood and glue it on top of the existing one, this way I could have avoided the sanding. But it would have been a different project.