Thank you for your comments.
The method I use for split repair primarily involves clamping mating pieces together before flowing high or medium viscosity superglue/CA into the crack. The glue literally flows into the joint and is best done in stages by adding glue, zapping with accelerator and then adding more. The resulting fit is extremely tight and I find superglue bonds better when joining pieces are pre-clamped. A squirt of accelerator cures the glue almost instantly and the repair can quickly progress to clean up and the finishing stages.
TIP: If superglue clouds when dry, simply add a drop more glue and the clouding will dissipate/disappear as the fresh glue amalgamates with the original glue.
Handles most often break on grain lines, so most broken handles can be repaired with little trace remaining of any previous problems/breaks. Low spots where material may have flaked/splintered away can be masked off and filled (again using superglue) before making good the area with file/scraper, abrasive paper and steel 0000 wool. Because superglue dries transparently, such repairs can be made to take on the appearance of dark grain lines as the timber beneath provides colour for the glue “filler”. 🙂
Missing parts – such as damaged handle horns – can readily be replaced and blended to match the original timber, but plain beech or apple handles can be most tricky to repair invisibly due to the need for accurate colour matching and airtight jointing. Dressing across freshly glued cracks tends to conceal such repairs as elements of wood dust from filing bonds to the glue and becomes a form of filler matching precisely with the surrounding timber. 🙂
Quite often you’ll find splits will close if a handle is re-humidified and then the simplest form of repair can be resolved via re-finishing, but should a split prove too large to fill via humidity (Typically an old split) or gluing, I tend to prepare filler strips using matching timber with grain oriented to match. These strips are mated tightly to the opening and then fitted into place (Left slightly proud of the existing surface) and then flushed to the surrounding surface once the glue has dried overnight.
In cases where repairs involve the use of water based glues, you’ll find the timber swells, but recedes as moisture evaporates during curing. This is why (As well as bond strength) we allow the repair to cure overnight before re-dressing filler pieces to their surroundings. 🙂