Monday, 21 October 2013

Home making field cutlery

Recently the spring broke on my lock knife i use for preparing game when hunting, i bodged it by wedging a piece of metal behind the spine. So now the blade doesn't flop about when i'm using it, but now it can't fold away any more. Then i thought why not just make a new one, after all i know how to work with metal and how to harden and temper steel.

The only sheet of steel i had to hand was 1.5 mm thick which was a bit thin for a sturdy knife blade, but it would be ideal for testing methods for making a knife blade with a tang. The sheet was covered in black paint so it was easy to score a knife design into it, scratch out a design between the various holes in it. 

Knives and the metal they were cut from.

 Then using a metal cutting blade in a jigsaw i cut out the rough shape,

Using a jigsaw to cut metal.

Trimming the knife into shape

then trimmed of any i couldn't get to on the first cut. It was then a simple matter of filing and grinding to the final shape i required, using an angle grinder, cutting disk, and the trusty old metal file.

Using a file to get the final shape

It could be done with just the metal file but takes longer, however i think you would get more control over the final shape this way.It's best to shape and drill any holes for the scales now, because it's a lot harder once the metal has been hardened and tempered

Any way i was left with three knives which i found fairly easy to shape, though with them being only 1.5 mm thick i was worried the might warp when i heated them.

Small bramble hacker, really needs to be thicker and heavier, but i can do it in principle

Small skinning knife, needs holes drilled for the scales (handle).

Back of blade has ribbing for thumb grip and little finger fits into the concave at the base.

 To harden metal it must be heated till it is red hot then plunged into water or oil, usually the blade and the first third of the tang is treated. I recently picked up 25 litres of a mystery oil for a tenner for this doing just that, it's cheaper than motor oil and even veg oil at that price. The cheapest would be old motor oil from a garage or scrap yard, though most places put it in a big old drum and find it to much bother to get back out again.

25 litres of hydrolic oil i reckon, had been sitting unused in a shop for 10 years so the basicly got it for a few pints.

To temper metal is to give it a bit of spring back after hardening so its not so brittle, it could be heated with a blow torch till it goes a blue colour or put in a oven at 200 degrees for one and a half hours. At the moment i can use my forge when casting metal to heat the knife blades at the same time, then give them a bit of spring using the oven method

There are many You Tube videos with loads of ways of making knives using old files, using an old piece of spring steel, or the way i've described. You can make machettes by just hardening the cutting edge in a forge, and even make a forge from an old cast iron wheel hub. I find myself looking on you tube a lot before tackling something new, or something i've not done for years and need a reminder of the details.

Any how i will be reporting how the rest of the project when i have time to complete it, as i seem to be juggling a few projects at the moment.


Wing Commander Sir Nigel Tetlington-Smythe.

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