Turn a Katana Into a Cutlass




Ever since I was a pirate-obsessed child I wanted a real cutlass, but not just any cutlass, an 1845-pattern cutlass. Yes, 1845 is completely the wrong era for English pirates, but it's still the cutlass everyone knows from movies and storybook illustrations. You can see this in the screenshots I took from one of my favourite movies, the 1990 version of Treasure Island (probably the best pirate movie ever made...) As far as I'm concerned this makes it the quintessential literary pirate cutlass.

Unfortunately, originals are very expensive and no one makes a replica, at least not available in Britain, so I decided to make my own. But I don't have the chops to make my own blade so I decided to borrow the blade from a different sword. Katanas are about the right shape and are readily available (although the government is clamping down on them again this year *fume*) so I bought the cheapest one I could find, £50 delivered.

A katana blade is quite long, and the handle is much too long for a cutlass, so I cut the end off the tang with a hacksaw and further used a file to eat into the blade by a further two inches or so. This brought the actual blade length down to 25 inches which looks right to me. Because it was a cheap katana the cutting edge is not hardened, so it was easy to file.

To remove the hamon (the milky pattern along the cutting edge) I dipped it into a strong solution of potassium permanganate for about eight minutes. You can buy this very cheaply online because it is used for etching circuit boards. I used half a litre in a bit of PCV pipe. The blade turned completely black (and got very hot during the etching process!) but after sanding the oxide off with some wet and dry paper I was left with a pleasing antique-looking finish, and no hamon.

Step 1: Making the Hilt

The hilt began as a piece of 1.5mm thick steel. The piece I used was nickel plated because that's what I had, but it would have been better to use plain steel since the nickel coating messed with my blackeneing method (see later). I made a cardboard template and used it to cut out the shape with a hacksaw and file. I also drilled and filed out a hole for the tang to fit through.

To create the bowl or cup shape I used a piece of timber (a bit of fence post actually) and gouged a shallow depression into it. Placing the steel over the depression and gently hammering it with a ball-end hammer quickly caused it to curl up and take shape -in fact I was surpsied how easy this was! I also hammered the edges of the hilt over a piece of steel bar so they fold in the reverse direction, which strengthens the thin part of the hilt (in retrospect it would be easier to do this part first while the steel is still flat). Once I was happy with the shape and size I made another hole in the thin end of the hilt for the peg on the end of the tang to fit into (if this doesn't make sense see later for how it is all constructed).

I then filed and sanded out most of the hammer marks (at least on the outside of the hilt) which also removed the nickel coating (or so I thought).

Apparently Naval cutlasses were painted black. However, I'm somewhat skeptical that they used regular paint back then, so I used an alternative traditional method of blackening with boiled linseed oil. The process is simple: clean the steel thoroughly with wire wool and acetone to remove any grease. Then heat the reverse side of the metal with a blowlamp and paint the linseed oil (use boiled, not raw linseed oil) on the other side. When it gets hot enough the oil will start to smoke and 'bake' on. Repeat this a couple of times and you will be left with a durable black coating that looks just like black satin paint! I did get trouble with traces of the nickel flaking off as it heated up, leaving un-blackened patches. Fortunately this is only visible on the inside of the hilt and rust may hide it later, but I learned my lesson: use only plain steel!

Step 2: Making the Handle and Peening Block

The handle I made from a piece of scrap beechwood, but any wood would work. It's made in two pieces with a channel chiseled out for the tang. Then I glued the two piece together and sculpted the handle with a rasp and electric sander until I had a shape I liked. Finally I stained and oiled the wood.

For each end of the wooden handle I made a spacer from craft foam (I coloured the foam black with a permanent marker). This helps to absorb any shock to the handle during the peening process, and also compresses to fill any gap between the handle and hilt.

I also made a brass washer thing to fit above the hilt to hide the less-than-perfect hole where the tang slides into the hilt, plus it's a cool detail.

Finally I made a peening block. This is a piece of thick (4mm) steel that slips over the peg on the end of the tang, which allows you to hammer or 'peen' the peg over without hammering all over the nicely-made hilt. A subtle detail is that the hole in the peening block should be filed at an angle; this means the peened metal will mushroom over and form a wedge which cannot come loose (you can see what I mean in the next step).

Step 3: Assembling the Parts and Peening

I assembled the component parts, stood the sword on a block of wood and proceeded to peen the peg with a ball-end hammer. This is a fancy way of saying "keep hammering until it mushrooms over!'. You don't have to be very violent, just firm with your hammer strikes. After about ten minutes it was nicely spread out and everything was tightly held. I considered filing the peened metal flat, but I decided I like the rustic look as is.

Step 4: Making the Scabbard and Baldric

I considered making a leather scabbard for my cutlass but decided the katana's saya would look good, and this would also avoid the embaressing 'floppy scabbard' problem that cosplayers will be familiar with! I simply sawed it to the right length, sanded off the varnish and stained the wood darker before waxing it (I like using wax rather than varnish; it's a habit).

I made a baldric from a pair of work belts -you can find out how in this cool instructable. The only difference is I used Chicago screws rather than rivets.

I am very pleased with the result. The only things I would change next time would be to make the handle a little shorter (I think 4 1/4 inches would look better) and to make the narrow end of the hilt even narrower so it smoothly meets the thickness of the handle. As it is, the weight of the sword when you swing it tends to make the bottom of your hand rub on the edges of the hilt. Fortunately I'm not in the habit of getting into prolongued Highlander-style combats!



    • Trash to Treasure

      Trash to Treasure
    • Tape Contest

      Tape Contest
    • Jewelry Challenge

      Jewelry Challenge

    2 Discussions


    4 weeks ago

    Надо попробовать!


    5 weeks ago

    This is great. I love the simple approach of just modifying an existing sword! Why start from scratch when you don't have to? Excellent work!