Thursday, May 21, 2015

KN11-2 CHEF'S KNIFE - LAYOUT AND GRIND

For this new KN11, I wanted to use some AEB-L 0.130" as I was thoroughly impressed by the KN9 I made a year ago. I traced the basic shape, but made the blade longer so it's overall length is closer to 13".
I cut the basic shape on the band saw. This has become one of my most used tools in the shop. See Porta-Band Bench Mounted Conversion.
Here's the blade with the pattern.
I used the spindle sander to shape the inside curve.
With a magnet, I use the belt sander to clean up the surfaces. AEB-L is really nice as it has a very clean surface from the manufacturer.
This it, ready for the initial bevel grinding.

I used a Blaze 60 for bevelling. Starting at the tip and drawing across.





Although this looks pretty rough right now, it will clean up with some 120 grit action. I'll clean it up a little and get the heat treatment done.

KN11-2 CHEF'S KNIFE - HEAT TREAT AND REFINED GRIND

Before going to heat treat, I need to make the holes for the pins to hold the bolsters and scales on.







The layout will be a front bolster, scale and rear bolster arrangement. It's laid out and punched before drilling.

Drilling with #30 and F bits and coolant.







Now for a wrap in some stainless steel to make an envelope.

Oven is up to temperature. A soak for 10 minutes at 1070°C (1958°F)
Into the copper plates to quench.

Once cooled until the gloves won't burn when touching it, cut open the envelope and get it right into an awaiting oven set to 185°C (365°F).

Two hour at tempering, then cool. Again for another two hours at 185°C.


After the blade is out of tempering, I start on grinding away the rest of the bevel. This is done evenly on both sides, frequently dipping in the water to keep it cool and preserve the hardness in the steel.

I use a caliper to check the thickness at the edge. I want this to be 0.020" and even.Some more grinding brings it down to spec.
Now for some scrubbing with sand paper and Windex. This takes out any scratches. I start one grit back, say 100, then go up to about 400 with wet sanding.
It's ready for the maker's mark.

KN11-2 CHEF'S KNIFE - BLADE FINISHING & MARKING

On the blade I am looking for small imperfections on the surfaces. I usually make a quick mark of the areas and work them with sandpaper and windex until they disappear.
The satin finish is achieved by sanding up to around 400 grit. Not usually more than 600 grit for a satin finish. Sometimes I will take the blade over to the buffing wheel and buff with green compound. This often reveals hidden scratches that need to be worked out again with sand paper.
Once satisfied with the blade finish, I clean with acetone, dry and apply my stencil.
The electro-etching pad is dampened with some electrolyte and applied to the stencil to etch my logo. As most people are right handed, I generally apply my logo to the left side of the blade.
Spray the etch area with some windex and wipe with a rag. This will neutralize the electrolyte. Then a quick buff with a blue scouring pad and it looks good.
Now to tape up the blade to protect it while we do the bolster and handle work.

KN11-2 CHEF'S KNIFE - FRONT BOLSTERS

For the bolsters I am going with 304 stainless. I like the corrosion resistance, but it's tougher to work with. I have a bar of 3/8" x 2" that I cut from with the band saw.
Once cut, I square it up on the grinder, then cut it into short lengths. One per side.






After clamping and drilling one hole through. Insert a temporary pin, then clamp the second bolster side. Now pull the pin out and drill through the hole.








Here I am using some temporary 1/8" pins to hold the pieces together for drilling.






Once the second bolster piece is clamped to EXACTLY match the first piece, pull the temporary pin and drill right through.







After the second hole is drilled, you can remove the bolster pieces and pin them together for shaping as a single unit. The focus is now on the fronts. 

Once the faces are trued and polished, I pin the two pieces back on the knife.






Grind the faces flat and take some away from the inside curve. Remember, these are temporary pins and will be punched out and replaced with proper stainless steel pins.

KN11-2 CHEF'S KNIFE - SCALES AND EPOXY

I have two pieces of yellow birch to go as scales. These I have stabilized with Stick Fast
I cut the front angle to match the slant of the bolster. This is easy on the compound mitre saw.
I clamp and drill through one scale. There will be three holes, two for 1/8" pins and another for a 1/4" mosaic pin.
I temporarily pin the first scale with dowel and clamp the second scale on as well. Then removing one dowel at a time I drill through the second scale.
I trace the tang shape and trim about 1/8" from the line to give some room to bring everything in line and leave some wood there for shaping.
I cut the pins to full width plus about 1/8". I touch up the ends with some sandpaper and remove any burrs.
Pins are ready. I'll clean and test fit everything before gluing.
Here I am mixing 5 ml of Brownell's Acraglas. The most amazing epoxy I've tried.
I used just about all the 5 ml of Acraglas. Making sure that the holes in the tang are filled. Once clamped I wipe up with Armor All wipes and let it sit overnight.

KN11-2 CHEF'S KNIFE - REAR BOLSTER

In my last build of a knife similar to this I put the front and rear bolsters on first and then attached the scales after. This build I changed the sequence to see if the process could be made easier. would work easier.

This is after the epoxy had set.
Here I have pieces of 304 stainless steel, about 1/4" thick by 1-1/4" x 5/8". I've cut and ground these to be a close match to each other.

I clamped with the vise-grip and drilled a #30 hole through the tang.





Once the first piece is drilled, I pin it with some temporary pins. Then clamp the second piece on with vise-grips. Then remove one pin and drill the hole right through all. Repeat for the second pin.
Now we have two pieces drilled and marked with a permanent marker.
On the band saw I cut them close to the lines to reduce the amount of grinding to be done after they are attached. I clean the holes with acetone and sand all the surfaces with sandpaper to clean them.
The bolsters and pins are pressed with a hydraulic press. I find this works better than hammering them.
I take to the belt grinder and a 120 grit belt to start the handle work. First on the flat faces. I like to use the belt longways against the flat platen for this.