Joe Kertzman - Grind a Blade the R.J. Martin Way

R.J. Martins Rampage fixed blade features a radical grind. The popularity of this grind has led to two successful folder designs, and the author plans to make a longer version of the fixed blade in the near future. It just goes to show what can happen when you push the envelope in blade grinding.

It has been 30 years since I first picked up a bar of steel and applied it to a moving abrasive belt in hopes of ending up with something that resembled a knife blade. I dont remember that first knife, but I remember the feeling of fascination and satisfaction that accompanied the process of grinding the blade.

The magical process of transforming a rectangular bar of steel into an edged tool by grinding away what doesnt belongthat is the essence of knife making.

When I was a high school kid in the 1970s, I started making knives. Back then, the field of knife making was still in its infancy. There were only a handful of knifemakers, none of whom lived near me. If there had been some, it wouldnt have mattered much because I couldnt drive yet! So, the possibility of visiting a knifemaker and learning by watching or by instruction was not possible for me.

Fortunately, there were books and I read every one I could find. I studied the picturesthey were most helpful, as the actual process of grinding is not an easy thing to describe. I am indebted to David Boye and Robert W. Loveless because these two men penned the words and provided the pictures for the book How to Make Knives that started me on my way.

I hope that in the following paragraphs I can provide for you, the reader, as much insight into the process of blade grinding as these talented individuals did for me. I am privileged to have Jim Cooper behind the camera lens in this effort, and I am sure that his talents will greatly help to clarify the meaning of my words.

If youre going to grind blades, youve got to have some sort of grinder! If you plan to grind dozens or hundreds of blades and make a living at it, you need a well thought-out piece of machinery capable of performing all the tasks required quickly, accurately and with a minimum of operator stress. In my shop, that machine is a Bader BM2 belt sander. Actually, I employ four BM2s and the larger Space Saver machine that takes a longer belt and allows me to sit down while I grind.

You dont need five machines; one will do it all if you equip it with the needed accessories. Ill point out the accessories as they are used in the grinding of the working blade for this book chapter. I should add that there are several brands or belt grinders available and each has its loyal following among knifemakers. I have never considered buying another brand, primarily because I havent found any grinding task that I could not accomplish easily with my Bader, and it seems to offer the best value.

The folks at Bader (Dan, Doug, Carrie and Paul) are incredible people who have assisted my career greatly over the past 20 years and have earned my loyalty. I will be using the BM2 to profile, hollow grind and taper a tang. I can also flat grind with a Bader, but I prefer to use a Sears 6 48 for flat grinding.

Id be remiss if I didnt mention the need for eye protection. The glasses I wear (although not stylish!) are prescription safety glasses of the best quality available. I have an industrial dust collection system in my shop, so I can grind without a respirator, but without such a system, a good respirator should be worn. If not a full face respirator, a good welding fume respirator that covers the nose and mouth is advised.

Youll also want a fire extinguisher close at hand. Grinding produces a considerable amount of small, hot chips. A bucket of clean water for dipping your work into is also essential. Youll notice in the accompanying photos that I dont wear gloves. Many knifemakers do, but I feel safer without them, and I have a much better feel for what I am doing when working barehanded.

A coarse belt snagging my glove and jamming my fingers between the work rest and a moving belt is not my idea of fun. If you choose to grind as I do, youll probably burn your fingers a few times in the beginning. After a while, your fingers will toughen up and your hands will become much more durable. In the meantime, dunk your blade after every pass, and remember the saying It feels good when the pain stops!

Grinding blades is not easy. You cant actually see what is happening between the blade and the belt while youre grinding. You have to see it in your mind. Thats rightblade grinding is all about visualization! You feel each pass, and then you look at the grind and see what happened. This visualization is the feedback.

Eventually (and it may take months or years), your mind will become so connected to the feelings in your hands and body that you will know precisely what is happening to your blade as youre grinding. You will develop muscle memory, and through experience, you will know exactly how to manipulate the blade to change or correct the appearance of the grind, whether moving the belt up the blade, correcting the plunge line or thinning out the edge.

This takes time, so, dont be frustrated if your first efforts are not successful. Experience is the best teacher, but there are some things you can do to help speed up the process. The first is to concentrate. You have to immerse your mind in the process at hand and pay attention. Listen to your grinder! It is talking to you!

Second, maintain a positive attitude. You have to convince yourself that when you step up to your grinder, good things are going to happen. Visualize the finished grind in your mind. If you cant see it before you start, its not going to happen! Third, dont get too hung up on achieving the precise grind line you envision. Instead, work on achieving symmetry and flow. If the finished grind doesnt have exactly the sweep you wanted, no one but you is going to know.

But, other folks will know if the grind line on one side of the blade does not match the grind on the other. I hear from new knifemakers all the time who say they got one side of their blade ground perfectly, but ruined the blade because the second side came out differently and they went too far trying to even up the grind lines. The flaw is in their approach; they should have focused on grinding a blade where both sides are symmetric, even if the appearance of the grind line isnt exactly what they envisioned.

R.J. Martins Kwaiken model showcases a chisel-ground blade. A chisel grind is a one-sided grind that eliminates the problem of maintaining symmetry in blade grinding.

Using a 10-inch length of A-2 tool steel, the author scribes the blade outline onto a blade blank using a template made from scrap G-10 and a carbide-tipped scriber.

I will be performing four specific grinding operations: Profiling, hollow grinding, flat grinding and tang tapering. If you can master these four operations, you can grind virtually any knife blade. Grinding a blades profile is the starting point for anyone practicing the stock-removal method of knifemaking.