My process for weighting chess pieces

I just shared my weighting process as a comment somewhere, and I figured why not turn it into a proper post so more people can see it. I noticed people are concerned about cracking chess pieces and thus wouldn’t even attempt to weight a wooden set. I did some research into the proper method to prevent this from happening. Below is the process I developed over time, which has been working well for me.

Preparation

You need to get yourself a little vise with rubber grips so you can hold a chess piece in place. I bought a highly rated one on Amazon for just C$38—a small one that I’ve clamped onto my work desk. With the rubber grips, you can apply a bit of pressure to the chess piece to keep it in place, but don’t overdo it. When I drill into a chess piece, I still hold it while it’s clamped into my vise, just for extra security. What you definitely don’t want to do is hold a chess piece in your hand while drilling.

Drilling out the bases

On the left in the photo below, you can see I used three different-sized Forstner bits, with each smaller one going deeper. I basically start with the largest Forstner bit I have, and drill as deep as I’m comfortable with going without drilling right through the base. You will have to estimate how deep you can go, and take the slope of the base into consideration. Be conservative with the drilling. You can always hollow the base out further later with more refined tools.

Do start with the largest hole, because the Forstner bits need something to hold on to. If you drill out the center first, making the wider holes will be quite impossible (ask me how I know).

The smallest hole is smaller than the central column, so as long as I drill straight, I can go really deep. But I stopped before reaching the halfway point, in part because this Romanian set I’m weighting is a top-heavy design, so I wanted to put as much weight as possible as low as possible. Placing weight higher up will result in a heavier piece, but it’s not going to do anything for stability.

Hollowing out the bases

On the right side in the photo above is another rook, where I hollowed out the base more after drilling the three holes. I used a Forstner bit at an angle to hollow it out.

Below you can see the result of the four hollowed-out rooks.

I later found that I could hollow out the bases even more by using a dremel with a spherical carving bit (essentially a little sphere with spikes). Below you can see two white knights—two of the more recent pieces I weighted. As you can see, I went closer to the edge with the Forstner bits to take away more mass from the base, and the use of the spherical carving bit resulted in a more even interior surface, and a more gradual transition towards the smallest hole. Basically, each hole I drilled with the Forstner bits gave me a “save/safe point” where I knew I didn’t drill through the surface, so any mass in between two of the consecutive drilling holes was safe to carve away as well. As you can imagine, I managed to add quite a bit more weight to these knights than the rooks above.

Weighting materials

As for weighting, I recommend using fine lead grain. Below I made a table of different weighting materials and their cost. Lead shot balls and lead grain are the two best methods after tungsten grain, but they’re also one of the cheapest methods. I can recommend tungsten grain for very small chess pieces, but for anything larger than a set with 8 cm (3.15") kings, it’s just not worth it.

So why fine lead grain rather than lead shot balls? For two reasons:

• Fine lead grain allows you to pack more mass in a given space, thus optimizing how much weight you can add to a set. If you use lead shot balls, the optimal way to fill a space is with sphere packing, which will allow you to utilize only up to 74% of any given space. But that’s with sphere packing, which is a mathematically optimal packing. Using 2.4 mm lead balls with random disperson, you would be utilizing about 58–62% of the space. Whereas, by using fine grain of varied sizes, you could ideally fill up to 90% of the space. That’s a significant difference!
• By utilizing more space and getting a denser packing, you reduce the amount of space the particles will have to move in. If you let the grain settle by using vibrations (lightly shake and swirl the chess piece to let the grain settle), you can lock it in place and prevent the chess piece having lose weight or acting like a little shaker.

Warning: The downside of using lead is that it’s poisonous. Don’t touch the grain, and wear a lead paint removal respirator mask with a P100 or N100 filter.

During the transfer process, some lead dust may lift in the air—some of which could be so fine you may not even see it—and potentially enter your lungs. This happened the first time I transferred lead grain I bought from the bag it came in into a canister. I saw a cloud of lead dust lift, and I thought I would be safe by just leaning back. I was not safe! Five minutes later, I started to feel dizzy. I filtered the room and drank a lot of water, and the dizziness vanished half an hour later. I have since used proper protection even when transferring small amounts of lead into chess pieces.

Weighting your chess pieces

Slowly transfer the lead grain into the cavity of your chess piece. Once you’ve added the lead, lightly shake the chess piece and swirl it around a bit to let the grain settle as far down as possible. This not only ensures an optimal utilization of space (thus adding as much weight as possible), but it will also lock the lead in place so you don’t end up with shakers.

Sealing the bases

If you work with lead, it’s important to seal it properly. I leave about 2 mm at the top, which I then fill with two-part epoxy. It’s denser than most wood types, so the 2 mm epoxy seal isn’t a great loss. And the seal properly locks the weighting material in place. Below are two Romanian kings with sealed bases.

I have been told that super glue will also work to lock lead grain in place, but I haven’t tried this myself.

Oh and in case you want to know, the thing that’s holding the chess pieces is a silicone brush/pen holder I got from Amazon. They sell under different names, so just search ‘silicone brush holder’ and they will show up in various colors. I use one for my makeup brushes, one for my pens, and I have one for my chess projects; I find them really handy to hold chess pieces in place. Those silicone clover patterns are only connected to the sides of the case, so you can spread them apart and push knights of various shapes in between them, and they will stay in place. Or at least, I’ve used it for various knight designs, and I haven’t had any yet that wouldn’t stay put.

Sanding the bases

Once the epoxy has cured (give it 24 hours), I sand it down with a dremel and a sanding bit to get an even surface. I place the piece upright to check if the surface is indeed flat and level. If the piece is a bit unstable, I sand away more from the center. If the piece leans a bit, I sand the side it leans away from. I don’t sand any further than the surface of the wooden base—or at least I try not to sand the wood.

Adding felts

The final step is to add felts. I like to use felt with a 20–35% blend of Merino wool and rayon, and a thickness of 1–1.4 mm depending on the size of the chess pieces.

I first cut squares that are a bit larger than the bases of the chess pieces. I then cover the bottom of the chess piece with tacky glue, and wipe the excess off some paper. I may dip and swipe the base through the excess glue on the paper if I see an area that lacks proper coverage.

I then gently place the chess piece on top of the felt square, and lightly press around the edge of the base. You don’t want to press the felt hard on the chess piece, as that will make the glue leak through the fibers of the felt, resulting in noticeable glue spots. Put the chess piece aside and let it dry for a minute or so, and only then press the chess piece down onto the felt. Now let that dry for a little while.

After a minimum of five minutes, you can cut the excess felt off. I use small Japanese curved sewing scissors by Kai. I recommend investing in some scissors like this, as they are optimized to cut through fabrics. I basically just cut around the edge of the base of the chess piece—pressing the scissors against the base, and letting the shape of the base guide the cutting. Once the excess felt is cut off, there may be a few irregular spots around the felt, which I cut away to get a reasonably perfect circle.

Results

And below are two photos of the result of the weighted Romanian chess pieces. The weight of the rooks I managed to bring from around 12 g to around 20 g, and the kings from 15 and 16 g to 27 and 27.6 g.

I’ve been told that some of these sets were factory-weighted, but about 2 g lighter than my pieces. So I’m pleased with that!

I had actually estimated that I would be able to get the rooks to weigh 22 g, so I was 2 g short of what I was hoping for; but I found that 20 g is more than enough to keep them stable on the board, even with their top-heavy design. So I’m satisfied. I could have used my tungsten grain if I required/desired heavier pieces, but it’s so expensive that I only use it for really small chess pieces where you can’t put much weight in the bases in the first place.

I’m still in the process of weighting the set. I finished the knights about a week ago, and I guess I’ve become more skilled at hollowing out the bases (and perhaps more confident in going deeper without reaching the surface), as I increased their weight from around 10 g to 20–22 g—double the weight!

Final thoughts

So this is my process to weight a wooden set. Most of this process evolved through experience with weighting carbolite and plastic chess sets. Weighting a wooden set is relatively new to me, but based on my experience so far and what I’ve read, the process outlined above should prevent cracking during the drilling process.

To prevent cracking of ebony pieces and other brittle woods over time, perhaps it’s better to use something like silicone rather than epoxy to seal the weight, as a more flexible substance will allow for the wood to expand and contract.

Let me know if my weighting process has worked for you!

Wow! As ever, a detailed and excellent explanation - with great results! Possibly this could be more than a CBE post - your own chess.com blog!

Thank you so much! I do have my own chess.com blog, and it so happens that I did a rewrite of this post with a bit more information, which I posted there: https://www.chess.com/blog/SilverSovietChess/weighting-chess-sets

An excellent article. I bought a good friend of mine a tournament-size, triple weighted plastic set last year, and he was blown away by it. Before that he'd only played with cheap, light, small wooden sets. He's much more into OTB chess now.

Thank you! Heavy pieces definitely feel satisfying to play with.

This thread layout to include spacing, headings, divider lines, clear pictures, occasional use of bold text along with precisely worded descriptions is-- ultra professional @WandelKoningin. You must be a trained journalist and/or educator? Or... just have a knack for writing and proofreading.

Kudos and nice work!

(Personal opinion: Wish that more posters would take such care.)

Oh thank you so much! That’s such a nice compliment.

I’m a graphic designer by profession. I also used to write a lot on Quora, and over time started treating my answers as essays. I currently write research-based articles on autism on my website, Embrace-Autism.com; and I sporadically write about Soviet chess sets on my Chess.com blog, Silver Soviet Chess. I wish I had more time to post chess articles at a greater frequency.