Sunday, November 1, 2015

DH44-02 INITIAL LAYOUT

I have a request for a Christmas gift. It's a hunter like the DH44 pattern but has a deeper blade and modified handle. I am making it from Crucible Industries' CPM154 1/8" x 1-1/2" stock.

 I have made a steel pattern for this one, roughly based on the HD44 template here.
I clamp the pattern down to the steel and trace the outline with a permanent marker.
Once traced I take the pattern off and start cutting out the shape on the band saw.
At this stage I am going close to the line. The inside curves are made with a series of cuts that can be easily ground out on the grinder.
On the belt grinder with a fresh ceramic 60 grit I bring the shape back to the line. The flat platen and work rest is great for this. Make sure your rest is 90° to the belt face.
Once the profile is made, I stand the piece up and remove the coarse scale and any pits in the steel surface.
Here I taper the blade portion of the knife. I use a magnet to hold it while I push heavily on the front (stabby end) of the blade. I don't want a radical taper here, more of a line from full thickness at the ricasso area to about 1/16" of an inch at the tip.
Now I layout where the handle will be. We need to know this before we start drilling in the tang. I am using a protractor to make the arc and drawing the shape with a permanent marker.
Once the idea for the handle is set, I determine the mid points and then the quarter points for the pins. This knife will have a lanyard hole of 1/4" diameter.
I like to center punch the pin holes before drilling. This helps keep the bit on mark.
Drilling the pin and lanyard tube holes. Numbered bits 12 and F are used for 3/16" and 1/4" pin stock respectively.
After the pin/lanyard holes are done, I de-burr the holes with a countersink bit. This helps me to identify them later when the whole tang is full of holes.
Now it's time to go nuts and drill a bunch of holes to lighten up the handle and better balance the knife. How many to drill? I check the balance by holding the knife in my hand and then resting the finger choil on my forefinger. When it feels like the handle and blade are the same, I stop drilling holes.  The idea here is the that steel removed when making the bevels is about equal to the handle material. Of course this entirely depends on the weight of the scales and pins that you choose.



This is the knife ready to start the layout and primary grinding.

DH44-02 SANDING, FILEWORK AND HEAT TREAT

After the bevels are close on the belt grinder I usually go over the blade with some sand paper for a wet sand. This isn't the final bevel as it will be carefully ground after heat treatment. The objective is get get the surface smooth and free of any large scratches that can cause stress during quenching.
Before going to heat treatment, I thought some filework would make a nice spine. Here I have marked off at 10mm (3/8") intervals
 I start with the half rounds alternating left and right on the marks.
Then I cut the leaves just above the half rounds. A small sharp needle file works good for this.
 This is before heat treat and will be cleaned up afterwards.
 Coating with Condursal Z1100.
 Bring the oven up to 1060°C for a soak.
Out of the oven into the warmed oil. Normally, I have been plate quenching stainless, but after a conversation with veteran knifemaker Ed Storch at the Metal Art Show in Wetaskiwin, I wanted to try some oil quench and see if it really gives an extra point or two of hardness.
In an instant the flame is out. I am lucky to catch the photo with the auto timer. From here it's immediately into the tempering oven at 200°C.








DH44-02 FINISH SANDING AND SCALES

After heat treatment, I take to the finishing belt to clean up the blade.






This is the effect of the conditioning belt. Most hand sanding is done longways, this belt will make a satin finish across the blade (more like what we see in production knifes).



For the handle I have two beautiful pieces of maple burl. I use a protractor mark the fronts in an arc.
I have made marks on the knife where the scale fronts are to line up. I clamp and drill one scale. For the centre pin and lanyard hole I use an F bit. For the two 3/16" pins, I use a #12 bit.
Once the one scale is drilled I fix it with some dowel.
Now to align the second scale to the first. Clamp, remove one dowel and drill through. Then tap the dowel back in and continue drilling the other holes. This keeps things perfectly lined up when drilling.
I use the bandsaw to get the scales into their approximate shape.
Using the same 3/16" dowel I pin the the scales together and finish the fronts.
After the cutting the pins and prepping the steel with acetone, I am ready to start the epoxy. This is West System's G/flex.







About 1-1/2 tablespoons of epoxy is mixed in the cup and applied with a Popsicle stick. Coat the pins and insert them. This ensures epoxy is all around the pin and there are no voids. Also the depressions in the filework needs to be fully filled.



After tapping the pins in, I clamp all around with medium force and wipe up the excess.

DH44-02 HANDLE WORK

After the G/flex has hardened overnight, I got the handle on the 4x36" belt sander and flattened the pins and evened out scales so they are equal thickness. It's easier to do this when they are on the knife as you have something to hold on to.  
Next I walk around and shape the profile bringing the shape of the scales close to the steel.
Here we can see the fill in the vine pattern. G/flex is looking good and doesn't smell like other epoxies.
 I sometimes use the 2" wheel on the platen to shape inside the belly of the handle.
For tighter rounds I go to the spindle sander or use the small wheel attachment on the 2x72".
Next the rounding of the handle happens. This is all done by eye and feel. I am checking how thick the handle feels and how it tapers, symmetry etc.

I like to do the bulk of the wood removal with a 120 grit belt.




Some more precise sanding goes on at the bench with 220 grit and 320 grit. I use blocks and pieces of dowel to get inside the curves.
A first application of mineral oil really brings the burl to life.