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We don't have any secrets at Tharwa Valley Forge and are very excited to be able to share all that we have learned about knives and bladesmithing. In addition to being the largest knife-making school in the world, we employ the largest number of full-time bladesmiths in Australia, so we've got a large base of knowledge to share with you.
Science, geography and warfare have influenced your kitchen utensils more than you might think.
The Sutton Hoo sword represents the state-of-the-art of sixth century sword making. For such an old sword the level of sophistication and complexity of its construction are surprising.
Like other swords of this era, it is a wrought iron sword with a resilient soft core and a sharp hard edge. The soft core consists of eight rods welded together that are themselves made from seven laminated layers twisted in alternating Z and S shapes. The sharp cutting edge is forge welded to the core and is a hard rod made from 180 layers of lamination.
Everyone knows they need to rest meat after cooking so that the juices don't run-out when they cut it. So why do so many people tear their steak apart with serrated knives that leave the juices all over the plate instead of in their mouths?
Asides from their highly specialised cutting geometry, Japanese kitchen knives are also notable for their distinctive handles. Home cooks frequently overlook the mechanics and ergonomics of knife handles, neglecting an element that factors into the performance of a knife as much as the shape, size, and grind of the blade.
Almost all professionals prefer carbon steel blades because they have the sharpest edges, stay sharp for far longer, and are easier to sharpen than stainless steel blades. With a modicum of knowledge and a minimal amount of care you too can enjoy the superior performance of carbon steel blades whilst getting a literal lifetime of service out of your knives.
I was making a large kitchen knife for a client, when I realised that it wasn't going to fit in my knife vices to shape the handle. So I made a new holder that bolts onto the existing bracket just for this one. It is a monster - 75 x 25 x 350mm. Enough for the biggest of blades. It needed three screws to squeeze the blade tight.
A nice feature of the Knife Vice Mark II design is you can have different sized clamps that fits different blade. Easy to swap in and out as required.
When hardening blades, especially large ones, warpage can sometimes occur. The choice of steel can minimise the risk, as can a good normalising cycle, but sometimes it just happens.There are a number of different ways to try and fix the bend, not all of them are guarenteed.
One gentle way is to use a Japanese straightening stick or "Magebo". I found this in Murray Carter's excellent book "Bladesmithing with Murray Carter". It is made with a large piece of hardwood, by cutting a slot or to (just thicker than the blade thickness) and making a handle. The bent blade is first tempered, then the back softened. This is to reduce the risk of breaking. The blade is then placed in the slot, where the bend is, and some gentle pressure applied to torque it straight. Gently does it.
It possiby could be used straight after quenching when still hot, I'll have to try it. I dont normally expect my blades to warp, but should have the Magebo hanging up near when I heat treat for emergencies.
I asked John Price from Radiusmaster what he recommends for belt grits in grinding a knife. His tip was to use a sequence of belt grits 60, 150, A45 then A6 to take it to almost a hand rubbed finish level. This is the smallest number of belt changes he recommends.
A good quality 60 will remove stock without putting too many scratches in. The 150 will clean out the 60 scratches before leaving an even finish. The A45 and A6 Trizac belts put the final touches on. The blade can be quickly hand sanded with 500 wet and dry for a satin finish, or higher grits before being buffed for a mirror polish.