How to Grind a Fuller on a Sword or Knife

The elusive fuller. For a long time I struggled with them. For almost as long I was really unhappy with the way mine used to turn out. Then I read Tinker Pearce's The Medieval Sword in the Modern World, and finally I was able to develop a technique of my own standing on the knowledge Tinker imparts in that seminal book that allowed me to fuller swords with excellent results.

I'm not going to discuss the merits of fullering swords here, so much has been written about it already. I will say though that aesthetically a fuller is a very attractive addition to a sword, and getting them right is challenging. If you know how though, it gets easier and easier each time you do it.

So here's the dilemma: most grinding equipment has a broad face. This means that it is not easy to get grinding gear into the fuller in the first place. The second problem is, when you get the grinder into the fuller, keeping it straight is difficult. People set up rigs, others use mills, others yet use CNC grinding gear. None of them are great solutions though for the following reasons (in order): rigs tend to require a fuller to be uniformly wide the length of the sword, as do mills. CNC gear is prohibitively expensive for the average sword maker.

The solution I find works best presumes you have a belt grinder. I don't mean a belt sander either, because take it from me, if you use them to make swords they won't last long - the wheels they use are not designed for heat and heavy contact like a belt grinder which is designed for metal. You really need something like this to do a fuller like the one I will be demonstrating. If you don't you can still do a fuller but you'll need to do them with an angle grinder on a stand, using a rig made of pieces of timber or steel to guide the angle grinder, but this guide is not about angle grinder fullers, but instead is about doing belt grinder fullers.



First mark out your fuller:



I like Sharpies because the ink has amazing staying power and they are non-toxic, but any permanent marker or engineer's chalk is fine.

As mentioned above, the contact wheel cannot be run up and down the area where I want the fuller (i.e. with the roatation of the contact wheel parallel to the blade), mine just wouldn't fit, it's 2 inches across. You might get away with it with a smaller contact wheel, but you would probably struggle to get the nice round hollow shape that most fullers are.

Next you start grinding! Hold the sword by the tang and the tip. Tinker points out that this part of the sword making is best done before any other grinding has been done, and it's very true. This is for a bunch of reasons: if you muck it up you can figure out how to fix it more easily, it's almost impossible to get a good result with a fuller on a sword that has distal taper or the edge bevels in place already. There are other reasons too, take it from Tink though, do the fuller first!

Run the sword up and down the blade with the contact wheel's rotation perpendicular to the blade, taking a little more off each time. I like using a 60 grit for this stage, but you might prefer a 40 or 80. You could theoretically do this part with a bench top grinder stone if you don't have a bench grinder belt attachment, but I haven't tried it so I can't vouch for it either way.

It will take time, believe me, you will probably be going at this for hours. I get my blanks prehardened so I keep them cool with a watering can I keep outside my grinding room. Always pour water over the sword on the grass outdoors WELL AWAY from powertools! Also, always wear rubber soled shoes when working with electrically driven power tools! I hope I don't also need to point out that you should ALWAYS, ALWAYS wear eye protection. It only takes one little piece of metal at the right angle to take out an eye, and no sword is worth that. I wear a heavy duty dust mask with a latex frame and replaceable catridge type filters, but I make swords as an occupation, and I understand this isn't practicable for the average hobbyist so get yourself some good dust masks and make sure they are fitted tightly. I use welding gloves to grind with, as when I was a starter making swords I suffered two major hand injuries from angle grinders, and f$%k they hurt, not to mention that I could have lost a finger. Just remember all this stuff. It can happen to you. That doesn't mean it will, but why the hell take the risk?

After many hours of grinding when you're happy with the shape move on to 80, then 120, then 320. Tink then uses a buffing wheel to remove the horizontal lines that will be left in the fuller, which is a fantastic way to finish it off. Unfortunately I don't have a buffing wheel attachment, so I do the next best thing which is get some emery paper over a small block of wood I rounded off on one side. These are easy to make, and you can make different ones for different types of fullers. The other great thing about 'blocking' like this is that it removes any waviness in the fuller. Tink can probably grind a fuller spot on by feel, but I'm not that good, so the block goes a long way to tidying my work up.

You'll be left then with a very pretty custom fuller like this:



I've tried a few other ways of doing grinding fullers but this consistently produces the best results for me. I've tried flap discs but they were problematic because the edges tend to score a crooked line in the fuller when used at an acute angle. I've also tried using flap wheels on a dril which results in bumpiness in the fuller.

With practice and a bit of patience you'll be able to use your belt grinder to create beautiful fullers using the technique described above. I've tried so many other ways of doing this, and to date, I've never found a technique that works as well.

Happy grinding!

See also: How the Japanese Make Fullers (Bohi)

Finished sword: