After a few years of daily practice, a sadhu board changes. The top face darkens where the feet meet the wood. The corners soften. The brass nails take on a deep gold patina. The finish thins under the arches. None of this is damage. It is the visible record of practice.
Some practitioners refinish their board every few years to keep it looking new. Others let it age and never refinish at all. Both are right. This guide is for the moment you decide to do a full refresh, and it walks through the process our Kostopil workshop uses on customer boards we are asked to restore.
First, decide if you actually want to
An aged board has character that a new board cannot replicate. Founder Eugene Oliynyk's daily-practice board, going on eight years of use, has a top face the colour of dark honey where his feet have stood. He would not refinish it for anything.
Refinish if:
- The finish has worn through and the bare wood feels dry and chalky under your feet.
- The surface has stains you find distracting (food, ink, animal).
- You are passing the board to a new owner who would like it fresh.
- You want to apply custom engraving to an existing board.
Do not refinish just because the board looks used. Used is the point.
What you will need
- Sandpaper, 180 grit and 320 grit, half a sheet of each.
- A sanding block. A flat scrap of wood wrapped in the paper, or a small purpose-made block.
- A vacuum cleaner with a brush attachment.
- A clean cotton cloth.
- Your usual maintenance oil (hardwax oil, tung, or boiled linseed).
- Painters' masking tape.
- Cotton swabs.
- Optional: brass polish, if you are also restoring the nails.
Power sanders are not recommended. They remove material too fast, dish the surface around each nail, and grind dust into the brass.
Step one: clean
Wipe the whole board with a barely-damp cloth and dish soap. Get the years of dust, skin oil, and floor grime off. Dry fully. This is not optional. Sanding over dirty wood drives the dirt into the fresh surface.
Step two: mask the nails
Tear small strips of low-tack tape and cover each nail head, or at least the rows you will be sanding through. You do not want sandpaper grinding across brass — it scratches the brass, fills the sandpaper with metal, and accelerates wear on both.
For tightly spaced nail patterns this is tedious. Allow half an hour for masking on a full-size board.
Step three: sand with the grain
Start with 180 grit on the sanding block. Sand the top face in long passes following the grain direction. Never sand across the grain — you will leave visible scratches that the oil will highlight.
Use light pressure. You are not removing wood, you are removing the old finish and a thin layer of stained surface fibre. A few minutes per face is enough on most boards.
Check progress by wiping the dust off with a dry cloth and looking at the surface in raking light. Old finish appears as patches with a slight sheen; bare wood is matte. When it is all matte, you are done with 180 grit.
Step four: sand finer
Switch to 320 grit and sand the same surfaces again. This smooths the scratches from the coarser paper and prepares the wood to accept oil evenly. Same long, with-the-grain strokes. Same light pressure.
Sand the side edges and the bottom face too, even if they look fine. You want a uniform surface so the oil takes evenly across the whole board. Spot-sanding leaves visible mismatched zones.
Step five: vacuum and wipe
Vacuum every surface with the brush attachment to lift sanding dust out of the grain. Then wipe with a clean cloth slightly dampened with water (no soap). The water raises any remaining loose fibres. Let dry fully — at least four hours.
Some refinishers go back over the surface with 320 grit one more time after the water-raise to knock the raised fibres back down. This produces the smoothest possible finish. Optional but recommended.
Step six: deal with the brass (optional)
If you want the nails polished as well, do it now while the wood is bare. Polish per our brass nail polishing guide. Remove the masking, polish, and re-mask just the heads before re-oiling so polish residue does not soak into bare wood.
If you are leaving the patina, skip ahead.
Step seven: re-oil
Apply your chosen oil with a clean cloth in long, with-the-grain passes. Use slightly more oil than for routine maintenance — the bare wood is thirsty. Cover top, bottom, and edges.
Wait fifteen minutes. Wipe off any oil still glistening on the surface. Let the board rest 24 hours.
For best results, apply a second light coat of oil after 24 hours, wipe off the excess, and rest another 24 hours. Two thin coats outperform one thick coat every time.
Step eight: remove masking and inspect
Peel the tape off the nails. Wipe each nail head with a dry cloth. If any oil has crept under the tape onto a nail, dampen a swab with rubbing alcohol and clean the head.
Check the whole board in raking light for missed spots, drips, or fingerprints in the finish. Touch up with a dab of oil if needed.
How long it takes
Allow a half-day of active work, plus 48 hours of curing time before practice. Less if you are skipping the brass polish.
If you would rather we do it
Ship the board to our Kostopil workshop and we will refinish it. We strip, sand, polish brass (if requested), and re-oil with the same hardwax oil we use on new boards. The board comes back looking close to new, with all its character (engraving, brass patina if you wanted it kept) preserved. Browse our full collection if you are also considering a second board for travel.
About the author. This piece was written by Eugene Oliynyk, founder of METADESK, together with the workshop team in Kostopil, Ukraine. Eugene has practiced daily on sadhu boards since 2018, including the most advanced 20Â mm nail-spacing boards. METADESK has been handcrafting wooden wellness tools since 2016. Reach the team at metadeskukraine@gmail.com.