Solomon’s Vintage Go Equipment Care Instructions
Howdy folks. Here’s a guide to vintage Go Equipment, based on my personal experience working with traditional Japanese materials. Various knowledge dumps can be found via Sensei's Library and elsewhere as well.
In this guide I'll cover how to clean and care for:
- What not to do
- What to do
- Soaking in H2O2
- What not to do
- What to do
- Understanding moisture
- Different types of OIl
- Paste Waxes
- Applying Oil alone
Clamshell stones are a delight. Unlike glass, they have a soft feel and each has a different pattern. Clamshell is the preferred material for white stone in Japan, where I learned to play.
When in doubt, treat clamshell like you treat your teeth: keep them away from water that is too hot or too cold, rub them only with something soft like a plastic brush, and keep them clean!
What NOT to do with your Clamshell:
- Don’t use a chlorine bleach - you’ll permanently dull the surface.
- Don’t fidget with stones while playing - it puts oil on them and is a bad habit.
- Don’t wash white clams with black pieces - slate and glass are hard, they will scratch clams.
- Don’t wash stones in a metal tub - you risk scratching or chipping the stones.
- Don’t wash with hot water - it will make the clamshell brittle.
- Don’t allow h2o2 to dry on the stones - either keep them submerged or rinse them off.
- Don’t take food-grade h2o2 lightly. It’s dangerous stuff. In fact, I'll add a section to talk about Hydrogen Peroxide…
Hydrogen Peroxide (H2O2) is dangerous:
Hydrogen peroxide is a surprisingly potent bio-toxin. It kills organic cells, which is why it is sometimes used topically as a wound cleaner. But the reality is that it kills all cells indiscriminately, reacting with Iron to basically rust us from the inside out. Treat it like poison.
Hydrogen Peroxide doesn't react with proper plastic polymers. That is why it can be stored safely in a bottle for long periods. A bottle of h2o2 left alone will eventually denature, becoming just o2 and h2o (oxygen and water).
Higher concentrations of h2o2 (or 'food-grade') come in bottles with vents, so that they don’t explode from pressure. But these higher concentrations are so powerful that they are even more dangerous to living tissue, like our lung tissue (if inhaled). H2O2 is very harmful if swallowed (possibly fatal - either by significant damage to the digestive system or by oxygen bubbles in the bloodstream). High concentrations of h2o2 can also explode if they come into contact with other substances like Alcohol.
Please wear safety gloves and eye protection, and don’t bring such h2o2 into your home if there is a risk that someone might inhale or ingest it.
Thanks for taking a moment to learn about safety! Now back to the instructions...
Ready to clean some Clamshell?
First, make sure you have clamshell stones and not yunzi or plastic or glass. If in doubt, shine a flashlight through the pieces to check for growth lines. The following steps are only for clamshell. Even so, visually check the stones to remove broken pieces.
You'll need a container, soap, a clean cotton towel, and a plastic colander.
First, choose the washing container. A plastic or wooden tub is great to wash them in (if glass is all you have, be very gentle). I prefer a cleaned yogurt container (1 quart). Prepare the container with room-temperature water and a bit of detergent - a few drops of dish soap is fine. Then gently add the white stones.
Massage the stones gently with your hands. If the stones are very dirty, let them soak for a little while, then try using a toothbrush or some other plastic brush to remove the grime.
Rinse the stones. If you have hard water, consider rinsing with Distilled Water to avoid spots.
Transfer the stones to a plastic or wooden colander to drain. Then spread them on a clean towel to dry, in a sunny spot if one is handy.
You can stop here. Seriously. This is enough for an average cleaning. In fact, most books only think it's necessary to wipe each dirty stone with a damp towel.
Soaking Clamshell in Hydrogen Peroxide (h2o2):
If you don't like the cream-colored patina that clamshell takes on with age, then you can try to restore the clamshell’s whiteness. You will need to get some h2o2, which comes in different concentrations. Household h2o2 is perfect, which is usually sold at 3% concentration.
Find a container that will be the bathtub for your clamshells. A hard plastic container is best, but a glass jar is ok too. I use leftover h2o2 bottles.
Fully submerge the clamshells in the h2o2. Add a bit of extra h2o2 on top to account for evaporation, so that the stones remain submerged during the next step, they should not be exposed to the air. Remember to also not expose them to other living creatures - store them in a place where pets or children cannot disturb them by accident.
Leave the clamshells submerged, soaking in h2o2 for at least 2 days, and preferably up to a week, briefly agitating the stones every 12 hours or so (wear protective eyewear and try not to splash). By 'agitate,' we mean to move them a bit - either stir them carefully or swirl them or even just massage the plastic container. You will probably see oxygen bubbles rising from the surface of the stones when you do this. You should start to see some improvement of color by the 48-72 hour mark.
Carefully drain them in a plastic colander, and rinse thoroughly to remove any remaining h2o2. If you have hard water (high in minerals), follow up with distilled water as a final rinse to avoid spots. Then dry them fully, spreading them on a towel in the sun.
That's it! All done, unless you want to go a step further and polish your Clamshell to get a glossy, slick finish:
Decide what to polish with. Raw ibotarou powder is traditional, but difficult to find. Paraffin wax is good and easily available - you can just use shavings of a plain, colorless candles according to the guys that make go stones for a living.
Polish one at a time, or massage a whole bunch of them in a cloth bag.
Allow 5 minutes for the wax to set on the surface.
Wipe off the excess wax with another dry white cloth.
All done! They should feel like glass now. Properly dispose of your used rags and bags properly.
Before you put the stones in the bowl, place a cloth at the bottom of your go bowl to protect it from any excess wax that you missed.
Slate feels great. It’s actual stone, so it is not slippery like glass or plastic. Matte black, dusty and dry, or polished glossy, they all feel good and earthy. When you place them on the board they should all look nearly identical (as long as you’re not sweating nervously).
What NOT to do with your Slate:
- Don’t wash Slate with the Clamshells. Slate is hard and can scratch them.
- Don’t wash Slate in a metal or glass container. Slate may be hard, but it can also be brittle and chip. Some glass types are actually harder than slate.
- Don’t use a mineral oil with additives, like essential oils. The stones will be coming into contact with different types of wood which may be sensitive; and some people have allergies.
What to do when cleaning Slate:
Find a plastic or wooden tub to wash them in. Prepare the container by adding some water and a bit of detergent (a few drops of dish soap is fine). Visually inspect the stones to remove any broken pieces, then gently add them into the soapy water.
If the stones are quite dirty, let them soak for a little while and try using a toothbrush or some other plastic brush to remove the grime.
Rinse the stones. If you have hard water, avoid water spots by rinsing with Distilled Water before you dry them.
Transfer the stones to a plastic or wooden colander to drain, then spread them on a clean towel in a sunny spot.
If you like the look of the slate, then you’re all done! Polishing slate will make them darker black, but it is a matter of personal preference and is not strictly necessary.
What to do when polishing your Slate:
Get a clean, white, cotton cloth that you don’t care about staining. That old-shirt-that-you-were-going-to-throw-away-anyway is fine.
Add a few drops of mineral oil to the corner of the cloth.
Rub each stone until it is coated with mineral oil then set it aside.
Once all the stones are oiled, wipe off the excess oil from each stone with another clean white cloth. This takes some time, so maybe watch a Go streamer on Twitch while you keep your hands busy.
Put a cloth napkin at the bottom of the bowl before you transfer in the polished slate. This will catch any excess oil you missed, so that it doesn't end up on the wood bowl or on the next board you place the stones on.
Wood is wonderful to interact with. It's an organic material, like we are, so it requires some upkeep, like we do. If we think of clamshells like our own teeth, then we think of wood being like our own skin. Skin will be damaged by the sun, or become rough in our old age. We don't like our skin to be too wet or too dry for a long time.
Our floor boards come from Japan, where it is very humid, so if you do not live in a humid climate then please read to the end of these instructions for using oil and wax to treat the wood.
Humidity is a huge consideration for wood - too much leads to mold, and too little leads to desiccation. Wood will change shape as it gains or loses water, so our first goal is to minimize any change in the wood's moisture level. The second goal is to recognize that change may happen, but to make sure that it occurs evenly across the entire piece of wood. We can best prepare for these changes by sealing the open pores in the endgrain, where moisture can enter and exit more easily.
Wood shrinks as it dries, so drying wood has a higher tendency to develop cracks - this is why firewood is much easier to chop once it has dried. Be mindful not to store items where there is a wind or draft that can dry them out. Also, always keep your board & bowls away from direct sun or heat to avoid warping.
Generally you should clean wood with a dry cloth. That may be all you need! Old wax may appear white on the board, and this is a good sign. In the image above, a new layer of wax is being applied from the left and you can see the dusty white of old wax on the right. This was a fairly thin layer that was easily incorporated into the new layer of wax, and didn't seem to interfere with the penetration of oil into the wood.
Remember to clean before treating, so that you aren't sealing in dirt or mold. Some stains may simply not come out of the wood itself, and may be water marks. If a deeper cleaning is needed, always test a small, inconspicuous area first, such as the inside of a bowl or the underside of the board. Tough stains might need a solvent, like a citrus oil, or something stronger like Barkeeper’s Friend (this is oxalic acid, and it requires its own safety precautions, like using a respirator/mask).
ALERT: the grid of some traditional gobans were made with Urushi lacquer. Urushi oil is the same product produced by the Poison Ivy family. Use non-latex gloves and a respirator, especially if using a product that can thin Urushi lacquer, like Turpentine or Camphor oil or Kerosene.
It can be hard to treat some Go boards or Go bowls because they are varnished. Many bowls are varnished or shellacked (or even coated in carnauba wax) right on the lathe when they are made. The varnish/shellac method is just a simple clear-coat; this shows off the natural grain and color of the wood, and is an impressive look, but it does little to protect the wood in the long-term. In fact, a lacquer barrier will interfere with attempts to preserve the wood with oil. Some people prefer to see bowls age naturally this way. But in our opinion lack of treatment leads to bowls becoming brittle over time and cracking, either due to an accident or simply by drying out.
Please note that I do not subscribe to the traditional wood finishes that Japanese manufacturers use, as my climate (and goals for refurbishing) are quite different. If you are looking for an authentic how-to, I'd suggest Mr. Kuroki's youtube channel as a good jumping off point.
In my opinion, treating wood is essential to taking care of it. Just like we use lotion to treat our skin, wood benefits from oil and wax. Oil penetrates the wood (provided that there isn't some coating in the way), and wax creates a surface barrier on the wood to keep away dust, debris, scratches, and insects. These barriers also help the wood maintain its internal moisture level. This method will generally not produce as shiny a result as varnish or lacquer, but will certainly help the bowls last longer. The polymerization of linseed oil, for example, will lend strength to the wood that will help keep it intact in case of an accident.
If you need to do some wood-care, read to the end of my instructions before diving in. You may also want to visit a woodworking website or two - there are dozens of YouTube tutorials you can watch to familiarize yourself with the basics.
Wood absorbs any oil it comes into contact with. This can even be inadvertent; on old gobans you will see darker areas on the lower edge of the board where oil has built up over time simply from picking up the board with bare hands. Using oil on wood is a permanent decision, so do some research and consider the type of oil you are using.
There are some oils we don't recommend. Many non-drying oils are vegetable-based and will go rancid over time and start to smell bad. We don't recommend products that will attract mold to the wood, like Japan Wax because it is a vegetable fat.
Generally, we will divide oils into two categories: drying oils and non-drying oils.
But first, this is a good time for another Safety Alert:
Safety is a major concern when handling wood-finishing products. Eyewear is a great idea, and you should also avoid prolonged contact of certain oils on your skin. Wear gloves if you may have a sensitivity, or at the very least wash your hands with detergent afterward. Always read the safety instructions on any chemical products. Some oils are nut-based, and thus a danger to those with nut allergies.
A drying oil refers to an oil that will Cure over time. Curing is a chemical process. Most drying oils will darken the wood, and you should consider whether you want to darken it a whole lot or just a little. Walnut oil and Tung oil are very commonly used, but they are nut oils (some people have nut allergies). Walnut oil is nice because it does not go rancid, it adds a nice dark shade to the wood. Tung oil also changes the color significantly and needs less frequent application. If you don't want to change the color of the wood, we recommend Raw Linseed Oil. Linseed is very light, and a very safe bet for most wood types. The only downside of Linseed is that it takes up to a week to cure - Boiled Linseed Oil (BLO) cures faster by including Volatile Organic Compounds (VOCs) to speed up the process, so because of those chemicals we don't recommend BLO for safety reasons.
Our most recommended drying oil is Special Linseed Oil, which is pure raw linseed oil that has been vacuum-heated to jumpstart the polymerization process. This product leaves less 'food' that would attract mold, and it cures in half the time as raw linseed oil. Please note that Curing is still a long process - an item may feel dry after only a few hours but may not have finished Curing.
A non-drying oil does not Cure, it will remain 'wet' even though it is within the pores of the wood. Our recommended non-drying oil is pure Mineral oil. This is a food-safe product that is commonly used on cutting boards and other kitchen surfaces.
Our Paste Waxes
We provide both a drying oil and non-drying oil version of Paste Wax. Paste wax is a combination of oil and wax, so that you can treat a board and finish it at the same time.
For a drying oil, we offer Monkey Wax, which is Special Linseed oil and beeswax with a bit of turpentine to soften the paste and to help the oil penetrate.
For a non-drying oil, we offer Monkey Butter, which is mineral oil and beeswax.
For both products, the beeswax comes from a friendly Colorado beekeeper named Chuck at Defiance Bee & Honey.
There are also plenty of commercial Paste Wax products you can search for. I've heard good things about Tried & True; I've also heard good things about Renaissance wax, which boasts finer particles. However, I don't know the ingredients in these various products, which is why I made my own.
If you know the type of wood you are treating, do some research. Begin with a google search for "oil and wax to use on fine ____ furniture" filling in the blank with the specific type of wood you are treating. Certain products serve the same functions as oil, but may actually be shellac or lacquer or chemical substitutes. It's really up to you, based on what result you want. You may want to treat the wood with oil first, following up with paste wax afterward.
Treating wood with pure Oil:
For a more robust treatment, consider treating the board with oil, then later finishing with paste wax. Before applying any oil, make sure that you have removed any old wax or other sealants - they will prevent the oil from penetrating and instead the oil will build up on top of them. There are a number of 'removers' or 'strippers' that you can use to dissolve old varnish and shellac, if it is present on your bowls. Be sure to read the instructions on any such products, so that you use them safely.
If you're unsure, you could simply sand the wood down - use something like 150-200 grit sandpaper to start, then 220-300 grit to finish. Going up to 400-600 grit for a super-smooth surface is not needed (in fact, that may actually close the wood pores and prevent you from being able to apply certain finishes). Remember to wear a dust mask to avoid inhaling sawdust, especially since it is hard to know how the wood was treated in the past.
Clean off any sawdust before applying a finish. You can do this with a vacuum, compressed air, wiping with a Tack Cloth, or just use a piece of old cotton fabric. I usually use a cotton rag and denatured alcohol (with a respirator in a ventilated area).
In this old photo I've sanded some bowls that were in particularly bad shape. I staged them on paper bags in anticipation of applying Boiled Linseed Oil (BLO), which has chemical drying agents that help reduce the curing time. BLO is not my most recommended finish, but it is very common in woodworking and was easy to find. Simple instructions for BLO are as follows:
- Work somewhere well-ventilated and wear protective gear.
- Apply the oil with a paintbrush (preferred) or a cloth.
- Coat the bowls fully, then allow 15 minutes to let the oil penetrate.
- After 15 minutes, wipe off any excess oil (before it gets sticky) and give the bowls at least 24 hours to cure before the next coat.
- Place a canopy over the bowls so that dust doesn't land on the wet finish.
- One coat of BLO is fine, but you can apply a 2nd coat, or even a 3rd. Each coating will make the wood slightly darker and slightly stronger.
- Avoid doing more than 3 coats of linseed, as the oil can get gummy or the finish may get splotchy. Gummy linseed can be removed with turpentine.
If you are using raw linseed oil instead, note that it takes up to a week to dry between coats. The upside is that raw linseed is food-safe. Here are the same bowls a few minutes later:
If you can get it, Polymerized (or 'Special') Linseed Oil is made the old-fashioned way without chemical drying agents. This is done by cooking the oil just below its flash point (a dangerous process) to begin the polymerization. The result is a food-safe product that dries faster than raw linseed, though not as fast as BLO. I now use the Special Linseed Oil offered by EarthPaint. Pure linseed gives a slightly better, 'buttery' feel to the wood, and the only downside is the longer curing time.
Safety Alert: Oils are flammable! These warnings should appear on any oil containers, but they bear repeating:
Take care not to store the oil or work with the oil near a heat source or open flame. Linseed oil polymerizes as it dries, and this reaction itself is exothermic, releasing heat; oil-soaked rags have been known to spontaneously ignite when wadded up in the trash, so they should be washed with detergent if being kept. If being discarded, spread oil-soaked rags flat on the ground to dry, and weigh them down with a rock.
Oily brushes can be cleaned with turpentine or mineral spirits. Speaking of turpentine (pine spirits), you can actually mix some with your linseed if you want to thin it down. Thinned down with turpentine, linseed will have more penetrating power into the wood, a good idea for a first coat if you plan on doing multiple coats.
For applying Mineral oil, keep in mind that it is a non-drying oil. This means that it doesn't cure. It stays wet, and soaks into the wood over time. If there isn't a good wax coating, it may still wick onto anything touching the wood, so don't leave important papers on top of the board. It is a food-safe and non-flammable petrolatum byproduct, used commonly on cutting boards and wooden utensils. Feel free to apply it generously, then allow it up to 8 hours for the wood to absorb it before wiping off the excess. Allow at least a week between applications to avoid bloating the wood through over-absorption.
A good coating of wax will help seal most wood. Many go boards will have white residue from previous treatments, and that is a good sign that the board has been cared for. Again, remember that oil won't penetrate finished wood (it will sit on top of it, potentially being sticky) so if your wood has a layer of lacquer or shellac then consider stripping it or using pure wax without oil.
Beeswax is an excellent choice. Beeswax is also handy for filling cracks that cannot be closed (like in a goban), though you may want to look into professional products that will match the color your wood.
Carnauba wax without additives is also fine, and even a tiny bit of carnauba (1%-5%) adds a huge strength to beeswax if you want to create a mix. I've used Briwax (get the new kind without Toluene) that has both carnauba and beeswax. I've heard that carnauba oxidizes over time (besides being harder and shinier) so I generally avoid it. I've heard Minwax is also a great product. In any case, be sure to read and follow any safety instructions on the product.
Japan Wax is also good, but is from Urushi (a tree in the poison ivy family), so read the alert above regarding handling it safely. It also isn't actually wax, it is vegetable fat, so it is a potential food source for mold. This is what board makers recommend, but the climate in Japan is very humid and very few people actually follow their instructions which involve cleaning it off and reapplying it periodically.
Whatever you decide to use, apply the wax thinly and evenly. Super-fine steel wool (#0000 grit) is a great tool to use to apply the wax if the wood is finished, as it really helps work the wax in and make the grain pop, while avoiding leaving big globs of wax anywhere. An abrasive plastic pad or synthetic steel wool are also great. Or just use a clean cotton cloth.
Give the wax coating up to a half hour to settle into the wood - it should be mostly dry to the touch - then buff the surface with a clean cotton cloth to polish it and remove the excess wax. The result is a thin coating of wax. Don't be surprised that the cloth picks up a lot of wax, and the cloth may discolor with wood residue. Again, wood is like skin - old, dry skin gets flaky and needs to be exfoliated.
If you are using a particularly hard wax (Carnauba), don't give it more than 30 minutes to dry before buffing, because it will be very tough to buff once it has fully set.
Remember that any wax containing a drying oil will need to cure before it is ready to use, so allow adequate time before bringing it back into your home.
I like ultra-fine steel wool, especially for gently removing old shellac. Don't use steel wool on oak, as the tannins of oak will react and leave brown stains. Second, only use steel wool if you understand the difference between finished wood and unfinished (raw) wood. #0000 steel wool is the equivalent of 400-grit sandpaper, and it can be easy to create nearly-invisible swirls (scratches) that will make themselves apparent once the wax dries. If using steel wool, brush in the direction of the wood grain to minimize swirls.
If you are working with a wood product covered in a layer of lacquer or shellac, then you can apply straight wax with #00 steel wool without having to worry about scratching the wood. Then buff with #0000 steel wool. The finish provides a layer of protection, so the steel wool is not abrading the wood itself.
If you have an oil-finished wood, then #0000 steel wool is usually fine as far as I am concerned, because the important thing is the bowls get a protective finish. But if you want your end-product to be a work of art, then it is safer to treat it like raw wood and use synthetic steel wool instead, or even just a cloth or plastic abrasive.
Although I love #0000 steel wool, it can also be a problem on the rough end-grain of a goban or other textured surfaces, which have a tendency to trap small particles. A plastic brush like a toothbrush works well in those areas, especially when assisted with a hair dryer to keep the beeswax soft. Or just use a cloth.
GLUE (binding cracked wood):
Sometimes a bowl falls on the floor, and sometimes they just dry out from time and weather. In any case, putting a bowl back together can be a fun and rewarding way to extend the life of your set.
Glue does expire, so make sure not to use anything over 3 years old. It should be stored at room temperature and not allowed to freeze.
Here's a quick set of instructions for using wood glue on wood bowls:
1. Clean and dry all the surfaces, then apply some wood glue to the parts that need to reconnect. You can apply wood glue to one or both sides. In the case of a hairline crack, you may need to smear glue in with a finger.
2. Clamp the pieces together firmly - wood clamps are great, especially with a small piece of cloth or plastic to act as a cushion between the clamp and the piece you are working on. Instead of clamps, rubber bands can work on round objects like bowls (avoid gluing the rubber bands to the wood - use a toothpick to create a small bridge).
3. Tighten the clamp until you get a good squeeze-out of glue beads. Don't tighten too much, or you will risk cracking the wood in a new place.
4. Beads and other excess glue should be cleaned up right away with a damp cloth or damp paper towel. Glue is water-soluble while wet, and once it dries it is a stiff mess that has to be scraped or sanded away. Conversely, use the damp towel somewhat gently, you don't want to push water into the crack where it can dilute the glue.
5. Give the piece at least 30 minutes to set before you remove the clamps, and preferably allow the glue 24 hours to dry fully.
Well, that's most of the advice I have on this topic. Feel free to reach out if you have additional questions.
Thanks for reading this far and I hope you learned something new!