A wobbly nail on a sadhu board is unusual. We seat each one in a precisely drilled hole using a press and a small amount of resin, and a properly maintained board can go decades without a loose nail. But it does happen, usually after the board has lived through extreme humidity swings or has been dropped onto a hard floor. This guide walks through the home repair, and tells you when to stop and send the board back to our workshop.
Diagnose first
Press each nail head with your thumb in turn. A solid nail does not move. A loose nail rocks slightly, or sinks a hair and pops back up. Sometimes you can hear a tiny click as you press.
Count how many are loose. One or two: a home repair. Five or more: something has happened to the wood, and the fix needs to address the cause as well as the symptom. Get in touch through our about page before you start.
Why nails come loose
The wood shrinks faster than the brass when humidity drops. The hole around the nail widens by a fraction of a millimetre. Repeated pressure (standing on the nail) drives the nail slightly deeper, and the resin bond breaks. Once the bond is gone, the nail rocks.
Fixing the loose nail is straightforward. Preventing more loose nails means addressing the humidity in the room where the board lives, which is covered in our storage guide for wooden balance boards.
What you will need
- A small bottle of two-part epoxy resin (the slow-cure kind, with at least a 30-minute working time).
- A wooden toothpick or two.
- A cotton swab.
- A small block of softwood, about the size of a matchbox.
- A small hammer.
- Painters' masking tape.
- A clean rag.
Do not use cyanoacrylate superglue. It bonds too fast, fills the wood pores instead of the gap around the nail, and turns brittle. Epoxy is the right material here.
The repair, step by step
- Mask the wood around the loose nail with low-tack tape, leaving only the nail head exposed and a small ring of wood right around it.
- Grip the nail head with pliers (with a soft cloth between pliers and brass to avoid scratching) and pull gently. If it comes out, set it aside. If it does not, leave it in place and work around it.
- If you removed the nail: look into the hole. If you see splintered wood or resin debris, scrape it out with a toothpick until the hole walls are clean.
- Mix a small batch of epoxy on a scrap of card. Pea-sized total, both parts.
- Using the toothpick, apply a thin film of epoxy to the inside of the hole. Do not fill the hole; coat the walls.
- Press the nail back into the hole and push it down to seat fully against the wood surface.
- Place the softwood block over the nail head and tap gently with the hammer to seat. Two or three light taps. You are not driving the nail; you are seating it.
- Wipe away any epoxy squeeze-out immediately with the cotton swab. Use a fresh swab dampened with rubbing alcohol if the epoxy has gone slightly tacky.
- Remove the masking tape before the epoxy cures fully, about fifteen minutes after mixing.
- Leave the board flat, nail-side up, for 24 hours.
If the nail will not stay seated
If the nail keeps backing out as you seat it, the hole is too worn. Two options:
First, thicken the epoxy with fine sawdust from a similar wood. The thicker mix fills the gap better. Press the nail in once, do not remove it, and let it cure.
Second, use a slightly thicker dowel approach: wrap a single layer of cotton thread around the nail shaft below the head, soak the thread in epoxy, and press the nail home. The thread wedges the nail tight while the resin cures.
If neither works, stop. The wood around the hole has compressed enough that a home repair will not hold. Pack the board and send it back to our Kostopil workshop. We can re-drill, plug with a hardwood dowel, and re-seat the nail in a fresh hole. We do this work at cost for any board we built.
Testing the repair
After 24 hours, press the repaired nail with your thumb. It should feel exactly like the nails around it. Stand on the board carefully and shift your weight around. Listen for clicks. If anything moves or clicks, give the repair another day and test again.
Once you are happy, oil the board lightly. The first oiling after a repair locks in the patch and blends the colour.
Prevention
One loose nail is a coincidence. A second loose nail within a year means the room is too dry for the board. Move the board further from heat sources, run a small humidifier in winter, or shift it to a more stable room in the house.
Most boards we make never have a loose nail. The ones that do almost always live within a metre of a radiator. Browse the collection for the full range of tools, and read our storage guide if you want to understand the moisture story behind why this happens at all.