Step 8 - Cleaning the Blade and attaching Bolsters 

 

With the knife blade heat treated and tested, I now clean up the knife before attaching the bolsters. Heat treating and quenching in oil causes the surface of the steel to change color, so I grind that off of the knife blade.

The biggest challenge is removing this discoloration from the file work. There are a lot of ways to clean up the file work, but normally I use a fine abrasive blasting process to get into the intricate patterns. Afterwards, I  use a variety of buffing wheels and compounds to bring the steel to its final luster.

Next comes the tang. This is a flat surface, so I use either a normal grinder or our surface grinder to grind this slightly. For example I may take .002" from each side (the reason I left the blade a little thick when surface grinding earlier). 

I now turn my attention back to the bevel grind. You may recall that I left this part of the knife a little thick before heat treating. I now finish grinding the bevel of the blade with progressively finer abrasive belts. Keeping the blade constantly cool during this phase is absolutely vital to the blade. As the blade is ground, heat is built up very, very quickly. Therefore, I dip it in the water constantly. In comparison to grinding before heat treat, the blade will now remain cool to the touch the entire time. This is critical, especially since the thinner section of the blade will heat the fastest and the hottest. If not performed correctly, the very edge could actually become hot while the rest of the blade feels cool to the maker. This would ruin the temper of the steel on the very most important part of the blade – its edge. So I take great care to keep it cool.

Once ground to the final dimensions, I buff the blade and any other parts of the steel which will be exposed. We usually start with a 600 or 900 grinding buffing compound and then go to white and green rouges. Again, I make sure to keep the knife cool during this process. 

The final finish is then put on the blade. I offer a few different finishes on our knives, including mirror finishes, glass bead blasted finishes, abrasive/matte blasted finishes, or a satin finish. By far the most popular finish for our knives has been the satin finish. The reason for this is that our knives are designed to be used (we hate it when they are not!). Most are used for hunting. As a knife is put through its paces in the field, it naturally gets scratched up a bit. The satin finish on the blade helps hide these scratches. They tend to blend in. That is not the case with a mirror finish where the knife looks great in the box, but once used, the owner may become disappointed in the look of the scratches. The satin finish is actually put on the blade using a 72 inch Scotchbrite™ belt in conjunction to a cork belt. This is performed after buffing out the blade. A close second in popularity is our glass bead blasted finish that provides a similar finish but without the vertical striations of the satin finish.

Again, there is no right or wrong when it comes to choosing the finish on your blade as it is all personal preference. 

Next I attach the bolsters to the blade. The knife featured in the pictures on this page is a Klipspringer model - which is a thinner all-around hunting, bird/trout knife, bush knife…etc. It's rather compact and has really struck a positive chord with our customers, hunters and non-hunters alike. Anyway, brass bolsters have been specified for this knife.

Bolsters are permanently pinned to the knife steel. Three 1/8 inch holes have been drilled through the bolster and tang of the knife. Many models have four, but the compact nature of the Klipspringer calls for three (many knife makers use two pins on even the largest of blades… which is perfectly acceptable). 

To start, we taper ream the bolsters from the outside in. The leaves the hole in the bolster a bit oversized on toward the outside, and then narrows to 1/8" as it nears the knife steel on the inside. This process is performed on both bolsters. The bolsters are then placed on either side of the knife and matching pins are put into place.

Once in place, the pins are hammered which will then lock them into position. This is done many times on both sides with portions of the pins protruding past the side of the bolster surface. A rounded ball hammer is then used to smash the pins into the bolsters further. The force of the hammering expands the pin, filling the tapered void. All three pieces of metal have essentially become one. The connection is incredibly solid.

At this point the bolster is oversized on the top and bottom of the knife. These will be ground down either now or after a handle has been attached.