Fixing oversize tuner holes

Here is a quick guide for an easy way to fix oversized tuner holes so push in bushes fit nice and snug. I would suggest doing this after you’ve applied any finish as that usually results in some overspray in the holes. If you plan to turn modern sized holes (10mm+) into vintage size (8.5mm ish), plugging and redrilling is the usual method. However if you are simply looking to get slightly oversized holes to work with push fit bushes this is a cheap and easy method. The usual disclaimers apply – proceed with caution and at your own risk.

You can see here that the hole is very slightly too large for the 10.8mm reducer bush. On this neck they are approximately 11mm, so only a little off.

The holes are covered with masking tape on the front of the headstock to prevent the superglue from flowing onto the face and superglue is applied to the entire circumference of the hole (face end) with a toothpick. I am using Loctite Ultra Gel as it is slightly flexible which I believe to be a good thing – we want the flutes of the bush to grip solidly without chipping.

Leave the superglue to dry for an hour and remove the tape. You can see that the superglue has built up nicely – there may be a film across the entire hole which can be carefully cut away with a boxcutter/craft knife. To get the new hole to the correct size take a *reamer and mark the required diameter with masking tape – I marked it at approximately 10.6mm to give some leeway. Carefully ream out the hole keeping the reamer level and using very little pressure – you want the reamer to do the cutting, not brute force. Test fit the bush a few times before you reach your marked size to check progress.  Stop once the bush just fits in the hole with finger pressure – final fitting will be accomplished with either a clamp or grips/pliers using gentle pressure.

Repeat for all holes that need reducing.

If you ever need to remove the bushes you can simply repeat this process before refitting to once again ensure a tight fit.


Keep an eye on our Clearance Corner for reduced prices on necks with oversized tuner holes.

*A reamer is a handy tool to have around and can save you from splitting a headstock by trying to force bushes into a too tight hole.




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