Monday, February 9, 2015

Choosing a grafting knife

    At this time of year, most avid gardeners are pouring over seed or nursery catalogs and dreaming about the spring planting season. For me, planning spring activities means cutting pecan scionwood and making sure my grafting box is well stocked with the proper tools and supplies. One of the most important tools for any grafter is a good grafting knife. Lets take a look at some the options.
   All knives suited for grafting pecans have two things in common. First, the blade has the "lamb's foot" shape that features a straight cutting edge and a sharp point. Secondly, the knife blade is beveled on one side and flat on the other. This means a grafting knife is sharped on the beveled side only, much like you would sharpen a chisel or plane blade.
    The first choice to make in selecting a grafting knife is to decide if you prefer a folding knife or a knife with stationary blade (photo at right: folding on left, stationary at right). I prefer using a folding knife because I can easily protect the finely honed cutting edge by closing the knife before walking to the next tree.
   Over the years I've collected several grafting knives. The photo at left shows four grafting knives that range in price from $16.00 to $113.00. From left to right these knives are:
     1. Antonini, model 5036L, high carbon steel, Italy, $28
    2. Barnel, model B6050,  high carbon steel, Solingen Germany, $65
    3. Tina, model 605T, high carbon steel, Germany, $113
    4. Victorinox, Grafting knife, stainless steel, Switzerland, $16

    First off, I prefer a knife with a wooden handle because I can keep a firmer grip on the handle while grafting. Nylon handled knives seem to slide around in my hand. Also, notice how the knife blade is attached to the handle of each knife above. With the Tina and Antonini knives, the cutting edge starts adjacent to the end of the handle. In contrast, Barnel and Victorinox have cutting edges that start well above the handle. Over the years, I have found that I can keep better control of the knife when the cutting edge of the blade is closer to the end of the handle and my hand.
    In choosing a grafting knife, the type of steel used to make the blade impacts how long the knife stays sharp and how easy the blade is to resharpen. Grafting knives are made with either high carbon steel or stainless steel blades. The photo at right shows two knifes built by the same manufacturer, A.E. Coltellerie Inc. of Maniago, Italy. The knife on the left has a high carbon steel blade, kotibe wood handle and is sold under the company's brand, Antonini. The knife on the right has a stainless steel blade, rosewood handle and is marketed in the US by A.M. Leonard Inc. High carbon steel blades are easier to sharpen and hold that edge longer than stainless steel blades. The only advantage stainless steel has over high carbon steel is that it doesn't rust. I personally prefer high carbon steel blades for grafting and save my stainless steel knives for cutting apples, frequently sampled from my wife's orchard.
   Often overlooked in choosing a grafting knife is how well the handle fits in your hand. The photo at left gives you an idea of how much handle thickness can vary between manufactures. In the photo, a Tina knife is shown on the far left, the Antonini knife is in the center, and the Barnel knife is on the right side.
    I have been using a Tina knife for grafting pecan trees for 35 years and have come to love that knife. However, the I've noticed that as my hands get older, my fingers seem to cramp up after a long day of grafting. I'm thinking that a little larger diameter handle might help with my hand fatigue. In handling the Antonini and Barnel knives, I found the Antonini just about right but the Barnel felt uncomfortably large. The bottom line is that you need to find a knife that fits your hand. I'll be giving the Antonini knife a good work out this coming grafting season to see how my hands hold up.