Weighting Chess Pieces

Many people say they would never attempt to weight a vintage wooden chess set for fear of cracking the pieces—and rightly so, since drilling without the right approach can easily cause damage.

Although I have extensive experience weighting carbolite and plastic pieces, I was recently asked to work on a wooden set. Before starting, I researched the best techniques to avoid cracks. What follows is the process I now use: a blend of methods I developed and refined over time, combined with the knowledge I gained while weighting my first wooden set.

Preparation

Before you start drilling, get yourself a small vise with rubber grips to hold your chess pieces steady. I use a compact, well-reviewed model from Amazon that cost me just C$38. You can mount it, but I have mine simply clamped to my work desk. The rubber grips let you apply gentle pressure without damaging your pieces—enough to keep it stable, but never excessive. When I drill, I still keep a hand on the piece while it rests in the vise for added control. What you should never do is hold a chess piece in your hand while drilling!

Next, you should get yourself a set of Forstner drill bits, as they excel at creating clean, flat-bottomed holes with minimal splintering. You use these to drill at relatively slow speeds, so you can fully control the hole it carves.

Drilling out the bases

In the photo below on the left, using Forstner bits of different sizes, you can see I drilled three holes—each smaller one drilled a little deeper. My approach is to begin with the largest bit available and drill as deep as I safely can without risking coming through at the other side. You’ll need to judge the depth yourself, keeping the slope of the base in mind. Err on the side of caution—it’s always possible to hollow the base further later with finer tools.

Always start with the largest hole. Forstner bits rely on the surrounding material for guidance, so if you remove the center first, cutting a wider hole afterward becomes nearly impossible (I learned that the hard way).

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 of the photo above is another rook, where I expanded the cavity after drilling the three initial holes. To do this, I angled a Forstner bit to carefully hollow out more of the base.

The photo below shows the finished result across all four rooks.

I later discovered I could remove even more material by using a Dremel with a spherical carving bit—a small spiked ball. In the photo below, you can see two white knights, some of the most recent pieces I weighted. This time, I drilled closer to the edge with the Forstner bits to take out more mass, then used the spherical bit to create a more even interior surface with a smoother transition toward the smallest hole. Each hole made with the Forstner bits served as a “safe point,” showing me where I hadn’t broken through the base, so I knew the material between two holes could be safely carved away.

Having removed more material from these bases, I was able to add more weight, and as a result these knights ended up significantly heavier than the rooks above.

Weighting materials

For weighting, I recommend using fine lead grain. Below is a table comparing various materials and their associated costs. Aside from tungsten grain, lead shot and lead grain are the best options—and also among the most affordable. Tungsten grain is worthwhile for very small pieces, but for sets with kings taller than about 8 cm (3.15"), the added expense simply isn’t justified.

Why choose fine lead grain over lead shot balls? Two main reasons:

• Fine lead grain allows you to pack more mass into the same cavity, maximizing the weight you can add. With lead shot balls, even perfect sphere packing only fills about 74% of the space, and in practice, random filling with 2.4 mm lead shot balls yields closer to 58–62% utilization of space. By contrast, fine grain of varied sizes can approach 90% utilization—a substantial improvement!

• Denser packing leaves less room for movement. If you let the grain settle by gently shaking or swirling the piece, the particles lock more tightly in place, preventing loose weight and avoiding the “shaker” effect inside the chess piece.

Warning: Lead is poisonous. Never handle the grain directly, and always wear a lead paint removal respirator with a P100 or N100 filter.

During transfer, fine lead dust can become airborne—sometimes so fine it’s invisible to the naked eye—and pose a serious inhalation risk. I learned this the hard way when I first moved lead grain from its bag into a canister. A visible cloud rose, and I assumed I was safe by leaning back. I was not. Within minutes, I felt dizzy. After filtering the room and drinking plenty of water, the dizziness passed in about half an hour. Since then, I’ve used proper protection every time I transfer even small amounts of lead into chess pieces.

Weighting your chess pieces

Carefully pour the lead grain into the cavity of the chess piece. After filling the space to about 2 mm from the edge, gently shake and swirl the piece to help the grain settle as deeply as possible. This maximizes the amount of weight you can add while also compacting the grain, reducing movement and preventing the piece from rattling like a shaker.

Sealing the bases

When working with lead, it’s essential to seal it securely. I leave about 2 mm of space at the top and fill it with two-part epoxy. Since epoxy is denser than most woods, that small layer doesn’t compromise the weight, and it locks the filling firmly in place. Below are two Romanian kings with their bases sealed this way.

I’ve heard that super glue can also be used to secure lead grain, though I haven’t tested it myself.

In case you’re wondering, the stand holding the chess pieces is a silicone brush or pen holder I found on Amazon. They’re sold under various names—just search “silicone brush holder” and it will show up in different colors. I keep one for my makeup brushes, one for pens, and another for chess projects. They’re surprisingly useful for holding pieces in place—even knights! The clover-shaped silicone slots are attached only at the edges, so you can spread them apart to fit knights of different shapes. So far, every knight design I’ve tried has stayed put.

Sanding the bases

After the epoxy cures (allow about 24 hours), I smooth it with a Dremel and a sanding bit to create an even surface. I then stand the piece upright to check that it’s flat and level. If it wobbles, I remove a little more from the center; if it leans, I sand the side opposite the lean. I avoid sanding beyond the epoxy layer itself—or at least do my best not to touch the wood.

Adding felts

The final step is applying felts. I prefer felt with a 20–35% Merino wool and rayon blend, in a thickness of 1–1.4 mm, depending on the size of the pieces.

I begin by cutting squares slightly larger than each base. After coating the base with tacky glue, I wipe the excess onto scrap paper. If an area looks under-covered, I dip and swipe the base through the glue on the paper to ensure even coverage.

Next, I place the piece gently onto the felt square and lightly press around the edges. Avoid pressing too firmly at the center of the base at this stage—excess pressure can force glue through the fibers of the felt, leaving visible spots. I let the piece sit for a minute before pressing it down more firmly, then allow it to dry.

After at least five minutes, I trim away the excess felt. For this, I use small Japanese curved sewing scissors by Kai. Sewing scissors are designed for fabric, so this will ensure an even cut. In my experience, your average scissors will just leave ragged edges, and the cutting experience itself isn’t smooth. I cut around the base with the scissors pressed against it, letting the shape guide the cut. Any irregularities left at the edges are carefully trimmed to leave a clean, even circle. Or an approximate circle, in any case!

Results

Below are two photos showing the finished weighted Romanian pieces. I increased the weight of the rooks from about 12 g to 20 g, and the kings from 15–16 g to 27–27.6 g.

I’ve been told that some of these sets were factory-weighted at about 2 g less than mine, so I’m pleased with the result!

I had estimated that I could bring the weight of the rooks up to 22 g, and I ended up 2 g short. Still, at 20 g they are stable on the board—even with their top-heavy design—so I’m satisfied. I could have used tungsten grain to push the weight higher, but given its cost, I reserve it for very small pieces where the base allows only minimal weighting.

I’m still in the process of weighting the set. I finished the knights about a week ago, and with more practice—plus greater confidence in drilling deeper without breaking through—I managed to raise their weight from about 10 g to 20–22 g, effectively doubling it!

Final thoughts

This is the process I now follow for weighting a wooden set. Much of it grew out of my experience with carbolite and plastic pieces, but with the adjustments I’ve described, it works well for wood, and minimizes the risk of cracking during drilling.

For ebony and other brittle woods, it may be worth sealing with a flexible material, such as silicone instead of epoxy, as this allows the wood to expand and contract over time without stress.

If you try this process, I’d be interested to hear how it worked for you!