matthewwh
Established Member
I haven't made that many handles but I've certainly fitted my fair share of them. As this is an easy bit to get wrong and comes at completely the wrong end of the project for mistakes to happen, the following may come in useful.
A round hole with the same diameter as the width across the flats of the tang works on softer timbers like beech (which is a lovely wood to fit). Once you get up to bubinga or ash, taking the width across the flats and the width across the diagonals and averaging the two will greatly reduce the chance of splitting the timber. For really hard timbers like rosewood I go a little closer still to the diagonal dimension.
As a rule of thumb, if you can get it on halfway by hand, then go ahead and knock it on all the way.
All the above is based on full tangs, square and virtually straight. For tapered tangs, stepped holes work better. A drill press is pretty much essential for this job, if you have one - great, if you don't it's worth looking for a mate who will let you use theirs. Metalworking bits work beautifully for drilling into endgrain, and if you use a centre finder and then countersink the spot you will minimise the risk of the tip wandering when you come to drill it.
You should always drill the hole deeper than the length of the tang for bolstered tools, so that the forces are transferred via the bolster. For unbolstered tools like files and rasps, the tang should bottom out in the hole.
Burning tangs in is a bad idea, in theory it's a shortcut to make the hole the same shape as the tang and save you a bit of simple arithmetic, in practice it reduces the strength of the timber at the point where you want it to be strongest and the handle may eventually fall off. There will always be a few people who have burned in tangs that have lasted twenty years, but there will be a heck of a lot more who have had worse luck. More importantly though, by warming the tool up you risk meddling with the properties that the toolmaker has so carefully imparted on the steel.
On decent tools the tangs will be annealed (normalised) so they are soft and can be bent a fraction to straighten the blade if it's not quite square and true. The best way to check this is to hold the tool up against a contrasting background and rotate it about its lengthwise axis while observing the bolster or neck. If the neck is running true then you've got it on straight, if not, clamp the blade in a soft jawed vice and gently lean on the handle until it is.
If you go too far and end up with a loose fit, there's technically nothing wrong with using a blob of epoxy, although if you've got the job right it shouldn't be necessary.
A round hole with the same diameter as the width across the flats of the tang works on softer timbers like beech (which is a lovely wood to fit). Once you get up to bubinga or ash, taking the width across the flats and the width across the diagonals and averaging the two will greatly reduce the chance of splitting the timber. For really hard timbers like rosewood I go a little closer still to the diagonal dimension.
As a rule of thumb, if you can get it on halfway by hand, then go ahead and knock it on all the way.
All the above is based on full tangs, square and virtually straight. For tapered tangs, stepped holes work better. A drill press is pretty much essential for this job, if you have one - great, if you don't it's worth looking for a mate who will let you use theirs. Metalworking bits work beautifully for drilling into endgrain, and if you use a centre finder and then countersink the spot you will minimise the risk of the tip wandering when you come to drill it.
You should always drill the hole deeper than the length of the tang for bolstered tools, so that the forces are transferred via the bolster. For unbolstered tools like files and rasps, the tang should bottom out in the hole.
Burning tangs in is a bad idea, in theory it's a shortcut to make the hole the same shape as the tang and save you a bit of simple arithmetic, in practice it reduces the strength of the timber at the point where you want it to be strongest and the handle may eventually fall off. There will always be a few people who have burned in tangs that have lasted twenty years, but there will be a heck of a lot more who have had worse luck. More importantly though, by warming the tool up you risk meddling with the properties that the toolmaker has so carefully imparted on the steel.
On decent tools the tangs will be annealed (normalised) so they are soft and can be bent a fraction to straighten the blade if it's not quite square and true. The best way to check this is to hold the tool up against a contrasting background and rotate it about its lengthwise axis while observing the bolster or neck. If the neck is running true then you've got it on straight, if not, clamp the blade in a soft jawed vice and gently lean on the handle until it is.
If you go too far and end up with a loose fit, there's technically nothing wrong with using a blob of epoxy, although if you've got the job right it shouldn't be necessary.
