Before I say anything else, I would like to thank the hard work and earnest effort to preserve, archive, and circulate the data and technical know-how amassed on these forums by those dedicated users; folks such as BladeSmith (Stacy), Dan Gray, Kevin Cashen, Ariel Salavererria, Tai Goo, and Salem Straub (to name just those a few whose work I've read and reread [and will continue to read and reread]) have all been incredible sources of information and inspiration on my journey to becoming a versatile, knowledgeable smith.
I would never have found the love and sincere calling in bladesmithing were it not for the wealth of wisdom, integrity, and humor such people bring to the community.
Getting to the point of this post--I am very particular about my plunge lines and consistently working towards perfecting the variables to offer both those classic styles while also keeping an eye towards other aspects of how we design them.
For "simple" straight plunges, I wanted to keep straight, consistent pressure evenly across the flat without risking too much bite or deviation. A hardened file guide is one thing, but I also considered the natural range of motion from wrist and elbow the length of the stroke; fixed guide-rod systems only create lateral movement, which does not serve well for convex or hollow grinds.
The other night I was rereading Salem's W2 Fighter with integral and hamon (mark my words--Salem's one of my biggest inspirations and quite probably going to be one of the best in the newest generation of smiths) and as I was skimming the section on hand sanding with his 1" bar, I considered making something similar strictly for plunge lines.
Pic first--then more rambling:
Now, as a cautionary for other novices and beginners reading this: Before I committed to doing this, I took my file--in this case a Mayco Swiss Pattern, Double Cut, Rectangular, #00--to a colleague at the university in geosciences and tested it with their XRF Spectrometer determine the steel, in this case W1. Without such foreknowledge, attempting to harden in Brine with surfactant could have had dangerous results.
My first steps are fairly well outlined in my warning--unsure if I was working with L6 or a W series file, I had it analyzed before grinding off the teeth along one side and setting the file in a vice to heat and bend.
I matched the contour for the bottom bend against one of my more frequently ordered designs by hunters that request hollow grinds--still relatively small, 3/4-1.5"x3-5" and ground on an 8" wheel. I then reversed this by convex grinding a piece of mild scrap to brace atop the vice jaw as I heated and bent the file 3/4 the length so that working the hollow plunge is more of a rocking motion (such as stroking a billiard cue) rather than a full stroke.
I then added the second curve so the tip end could still be use for working flat grinds along the wrist's natural angle. To accomplish this, rather than flip the file upside down in the vice and bending straight, I moved the file lower. I keep my vice's fixed jaw parallel to the bench edge--something I started just as a means of truing, but found aids in providing support when clamping longer objects. I then heated the file from underneath and bent the file backwards to meet the bench edge, and provide a stable angle.
I then ground the tip at an angle because, well, I rest my left thumb there and it just seemed practical to keep my thumbnail level with the ridged edge so I can apply more even pressure.
I then triple normalized the entire file in my forge and then annealed it in ash and vermiculite to relieve stress.
To temper the file back to reasonable hardness, I made a tempering "clamp" similar to Goddard's tempering gizmo (though I'll never understand why he'd suggest brass) out of two pieces of angle iron. I'd hoped that between keeping direct flame off the file, and reducing the water's impact on the teeth, those stress risers wouldn't initiate a fracture.
Rather than cool my brine, I warmed it to about 110-120 degrees and did a full vertical quench before letting it soak in the oven twice at 400.
As you can tell from the picture, it survived--university's RC tester showed her at 61.
I cleaned off the crud using electrolytic rust removal and gave the end a brush of lavender nail polish (compliments of the wifey) as I'm used to just quick color coding my files (red = bastard, blue = single cut, purple = 00 double cut, and green = 1-2 Swiss double cut fine) so I don't pull a Mr. Magoo trying to peep the cut through my magnifiers.
Given Time, a proper grinder and platen, experience, and practice, I guess it will eventually be relegated to just a simple sanding stick, but it was fun to make and the experience is going to come in handy eventually.
I would never have found the love and sincere calling in bladesmithing were it not for the wealth of wisdom, integrity, and humor such people bring to the community.
Getting to the point of this post--I am very particular about my plunge lines and consistently working towards perfecting the variables to offer both those classic styles while also keeping an eye towards other aspects of how we design them.
For "simple" straight plunges, I wanted to keep straight, consistent pressure evenly across the flat without risking too much bite or deviation. A hardened file guide is one thing, but I also considered the natural range of motion from wrist and elbow the length of the stroke; fixed guide-rod systems only create lateral movement, which does not serve well for convex or hollow grinds.
The other night I was rereading Salem's W2 Fighter with integral and hamon (mark my words--Salem's one of my biggest inspirations and quite probably going to be one of the best in the newest generation of smiths) and as I was skimming the section on hand sanding with his 1" bar, I considered making something similar strictly for plunge lines.
Pic first--then more rambling:
Now, as a cautionary for other novices and beginners reading this: Before I committed to doing this, I took my file--in this case a Mayco Swiss Pattern, Double Cut, Rectangular, #00--to a colleague at the university in geosciences and tested it with their XRF Spectrometer determine the steel, in this case W1. Without such foreknowledge, attempting to harden in Brine with surfactant could have had dangerous results.
My first steps are fairly well outlined in my warning--unsure if I was working with L6 or a W series file, I had it analyzed before grinding off the teeth along one side and setting the file in a vice to heat and bend.
I matched the contour for the bottom bend against one of my more frequently ordered designs by hunters that request hollow grinds--still relatively small, 3/4-1.5"x3-5" and ground on an 8" wheel. I then reversed this by convex grinding a piece of mild scrap to brace atop the vice jaw as I heated and bent the file 3/4 the length so that working the hollow plunge is more of a rocking motion (such as stroking a billiard cue) rather than a full stroke.
I then added the second curve so the tip end could still be use for working flat grinds along the wrist's natural angle. To accomplish this, rather than flip the file upside down in the vice and bending straight, I moved the file lower. I keep my vice's fixed jaw parallel to the bench edge--something I started just as a means of truing, but found aids in providing support when clamping longer objects. I then heated the file from underneath and bent the file backwards to meet the bench edge, and provide a stable angle.
I then ground the tip at an angle because, well, I rest my left thumb there and it just seemed practical to keep my thumbnail level with the ridged edge so I can apply more even pressure.
I then triple normalized the entire file in my forge and then annealed it in ash and vermiculite to relieve stress.
To temper the file back to reasonable hardness, I made a tempering "clamp" similar to Goddard's tempering gizmo (though I'll never understand why he'd suggest brass) out of two pieces of angle iron. I'd hoped that between keeping direct flame off the file, and reducing the water's impact on the teeth, those stress risers wouldn't initiate a fracture.
Rather than cool my brine, I warmed it to about 110-120 degrees and did a full vertical quench before letting it soak in the oven twice at 400.
As you can tell from the picture, it survived--university's RC tester showed her at 61.
I cleaned off the crud using electrolytic rust removal and gave the end a brush of lavender nail polish (compliments of the wifey) as I'm used to just quick color coding my files (red = bastard, blue = single cut, purple = 00 double cut, and green = 1-2 Swiss double cut fine) so I don't pull a Mr. Magoo trying to peep the cut through my magnifiers.
Given Time, a proper grinder and platen, experience, and practice, I guess it will eventually be relegated to just a simple sanding stick, but it was fun to make and the experience is going to come in handy eventually.