Hello All,

A couple people asked about this subject, so I put some thoughts together. this installment deals with the tang. Next installment covers the handle material itself. I hope you find it worth a read.

Tips on Success for Full Tang Knives Part One
by Paul Granger of Largo, Florida copyright 2006

The following is of course my opinion and my method. There are as many ways to do a thing as there are people who want to do it. And most of them are right.

In a full tang knife, the maker wants no visible gaps between any part of the handle material and any part of the tang. In part one, we'll consider the tang.

The tang must be flat. It is just that simple. If you have a surface grinder that will do the trick (Although I would still advise using the methods explained in the "removing less material" part of this article). You must sand it flat. There are two ways to increase the efficiency of doing this. First let's address FLAT.

You can not sand a surface flat by using something that is not flat to back up the sandpaper. Therefore I use a piece of safety glass approx half again as big as a full size sheet of sandpaper.

First put down a soft, clean cloth (that is bigger than the glass) on the front right corner (this is all written from the point of view of a right-handed person) of your work surface . Now stand on (or think from) the right end of your work space. Then using a good quality masking tape, I adhere approx 25mm of the far wide side of the paper to the near wide side of the glass. Then Flip glass and sand paper over and, using plastic tipped hand clamps (I use Pony clamps), clamp glass to your work surface (hanging over the front and the right about 10mm) so it won't move. Then pull sandpaper tight to the far wide side of the glass and tape tight as can be. Now you have something like a big resurfaceable grinding stone.

You will need something to use as a handle to move your blade across the sanding surface. I have made a bar magnet by using about six small rare earth magnets about 10mm round sandwiched between two bars of steel that are about 4mm thick, 10mm wide and 120mm long. To make one first lay a double layer of wax paper on a metal surface that is very flat. I put the magnets on one bar with as little a gap between them as possible and cover the magnets with silicone sealant, non-metallic 2-part epoxy or construction adhesive. Apply the other bar, squish them together and lay the edge (so that both pieces of metal bar and each magnet is touching the wax paper. Let it dry thoroughly and clean it up.

Now you can move the almost flat of the blade across the very flat sanding surface until the flat of the blade is flat. This will require some practise until you learn to apply pressure only to the middle of the blade along the full length of your stroke; otherwise you'll have a thick middle and two thinner ends (as you may rock the pressure from one end to another with each stroke). Prolong your sanding surface by keeping it clean. Use a speaker magnet in a plastic bag and periodically run it lightly over your sanding surface to remove metal accumulation. When the mag-in-bag gets too furry, turn the bag inside out, empty it out and replace.

Now after a few hours, you may think, "this is taking so long... Is there any way to spped this up?" Well, I'm glad you asked! Now we'll discuss the second way of increasing the efficency of acheiving a flat tang.

You can speed up the process dramatically by simply removing less metal with each stroke. There are two chief ways to do this. With either a hollow ground tang or a series of holes in the tang.

In figure I (above) you'll find a perfect world where all things are forever flat. Sadly perfect flatness is rare (especially handle material, which we'll study in part two).

In figure II (above) you'll find one solution. Grind a slightly concave (or hollow ground) area on all the flats (both handle slab inner sides and both sides of the tang). Before you begin this, be sure to drill all pin, bolster and thong holes. If you wait to do the holes until after hollow grinding the tang, your drill bit will wander on the slopes.

In figure III you'll see an end view of the tang grinding in progress. This is not a scale drawing, so don't grind that deeply on both sides.

In figure IV you'll see the other method of removing material. Again drill all of your pin, bolster and thong holes first. Then Drill holes all over the tang. Keep these holes about 5mm from the edges and the pin holes. Keep them about 3mm from the other material-removing holes. If you accidently overlap a couple material-removing holes, no worries. Stop drilling holes well short of where the handle or bolsters will end (so the holes don't show on the blade). ALWAYS, ALWAYS slightly counter sink all the holes. First it helps with pin alignment during assembly and second, if you are using stainless, doing this will help avoid stress fractures. Below you'll see a hole-ridden tang.

Now your full tang is ready for a perfect gap-free fit. In part two, we'll examine how to prepare your handle material for the same gap-free fit. Thank you for reading my post.

BTW While you can (often) bend a bowed, heat treated carbon steel blade back into proper shape (if it is edge quenched), here's another way to deal with the same bowing problem: