How To Carve Steel - Wormy Wood
Posted 26 February 2009 - 02:10 AM
This is my method; Iím certain there are other ways to accomplish the same thing. I use power tools when it makes sense, and I donít apologize for it. If you enjoy doing things in the traditional ways, then may you have every success.
WARNING!!!! EYE PROTECTION IS ABSOLUTELY REQUIRED. The techniques described here are dangerous, and not for inexperienced persons. Know your tools and safety procedures!
Hereís my starting canvas, 5160 carbon steel, with copper grips. The steel has NOT been heat treated yet, so it is still soft enough to engrave and carve. Iíll harden and temper the blade after all engraving and carving is complete on the blade, and before I begin to engrave and carve the copper grips. There is some risk to the blade during the quench, so Iíll not expend the effort on the grips until I know I have a good blade. I wish I knew a method to allow the engraving and carving AFTER heat treating, but I donít, so I just take the risk. Consider the turtle, who never gets anywhere without sticking his neck out...
You can see one side of my pattern in the background, and Iíll be transferring the bark pattern part of it to the steel of the blade. Donít forget to flip the image horizontally in the computer, or youíll get a mirror image of what you thought you wanted. I print it out on a laser printer (you can use a toner-based copier as well), place it face down on the metal, and use a cotton swab dampened with lacquer thinner or acetone (fingernail polish remover). The liquid will dissolve the toner and deposit it on the metal. Be careful not to use too much, or the toner will run and youíll have a blurry transfer.
Here are the tools Iíll be using for the carving portion. For the engraving, Iíll be using a Lindsay Palm Control. I wonít go into how to engrave, since thatís way beyond the scope of this tutorial. If youíre interested in engraving, I suggest you start at www.engravingforum.com and http://igraver.com/forum.
On the left is a 35,000 rpm NSK micromotor grinder, with carbide burrs. I get the 4 sizes of carbide burrs I use from http://www.lascodiam...ts/stndcbhp.htm. I use the 3/32inch shanks, but 1/16 inch shanks are available. Below, circled in red, are the 4 sizes I use.
On the right is the hand piece for my Foredom flex shaft grinder. I use these two types of Scotchbrite polyester abrasive pads for a LOT of my knife work. The olive drab is the coarsest, and the maroon is finer. The coarse will leave a brushed finish on steel, remove burrs, quickly eat off fire scale, and will rapidly smooth copper. The maroon will simply shine the metal. I use a standard mandrel with a small washer on each side of the pad - if you omit the washers, the pad will quickly tear out the center. I cut small squares and just punch the mandrel screw through the center - donít bother cutting them round, as they will round up very quickly in use. Also, donít use them full speed, or they wonít last long. About quarter throttle seems to work the best.
After applying the bark pattern, I engraved the lines, as shown above. The blade is held in a small pitch bowl, filled with lead and pitch from www.northwestpitchworks.com. Note the duct tape over the edges of the blade for safety.
I used the NSK micromotor grinder and the #2HP carbide burr to texture the bark segments. I cut a radial channel, starting in the center and stopping about a millimeter from the engraved edge. Here the radial cuts are shown in red. This first set of cuts looks pretty good at the edges, but usually leaves a confused looking center. I go back for a second set of short radial cuts in the center area, stopping well short of the edges.
Iíve used Birchwood Casey Super Blue to darken the engraved lines. Iíll be removing the blue several times during the process using the Scotchbrite pads and Foredom flex shaft, and reapplying several times as well. I prefer the Super Blue because it will provide a nice brown patina for the copper as well as a dark black for the steel.
Above is the final bark texture, smoothed with the olive drab polyester pad, and blued once more. Note that the untextured area in the center (which will be bare wood) needs to be cut down below the level of the bark.
Since Iíll be cutting next to engraved lines, this is a good place to talk about cutting strategy. The image on the left shows the first cut using a carbide burr, running along an engraved line. Iím holding the grinder in my right hand, and cutting from top to bottom. Since the burr is rotating counter-clockwise (the underside of the burr is rotating towards the bottom of the image), the best cutting action is against the rotation (towards a right-handed carver). Itís also the ďSafeĒ direction. I say ďSafeĒ because like the tires of your car, the burr rotation wants to drive the burr towards the top of the image (away from a right-handed carver). In this case, a slip will tend to cause damage above the burr (away from me), but probably not damage the engraved line Iím cutting next to. If I slip, or the burr unexpectedly gains extra traction, itís away from the ďSafeĒ direction that the tool wants to go (up in the image, away from a right-handed carver). The direction is ďSafeĒ because any unexpected damage wonít be in that direction. The idea here is to realize what direction the tool will cut best, and the direction that any damage will occur, and orient your carving to exploit that knowledge. Of course, you wonít always be able to carve in an optimum direction (thank you Murphyís Law). In those cases you need to realize what might happen and be prepared to counter it. Fortune favors the prepared.
Burrs will suddenly gain extra traction should they snag an edge. In this particular case, should the burr catch the edge of an engraved line in the ďDangerĒ direction, the tool will suddenly move away (up in the image), damaging the edge and any metal the burr makes contact with. Also, the same will happen should a corner of the blade be encountered in the ďDangerĒ direction. The burr will suddenly gain traction, jerking the burr over the corner, damaging both the corner and any metal beyond. Should you need to carve near an edge, the safest option is to carve against the rotation of the burr and towards the corner, where a slip wonít pull the tool over the edge.
Here Iíve successfully cut along all the engraved lines. The image on the left shows the direction and sequence of cut along the engraved lines to the left. Iím trying to cut away half of the line, leaving the other edge untouched. The image on the right shows the direction and sequence of those cuts - note that I rotated the blade 180 degrees so I could keep the engraved lines to the left side.
At this point, now that I have carefully ďoutlinedĒ the edges (remember coloring in kindergarten?), I have a ďsafeĒ buffer zone between the mass of metal in the center I want to remove, and the bark that I donít want to damage.
Here Iíve completed removing the metal in the gap of the bark. Itís deepest at the top of the gap, and shallowest at the bottom edges of the bark where it meets the undisturbed metal of the blade surface.
Hereís how I hold the grinder (like a pencil) and the position for carving along the engraved lines on the left of the gap.
Here is the gap fully carved, and blued. I used several sizes of burrs here, starting with a larger one to remove metal quickly, and smaller ones to get right up next to the bottom of the engraved lines.
Since the burrs are round, thereís no way to get a 90 degree bottom to the cut. I use successively smaller burrs to approach that goal.
Now itís time to begin carving on the rotten wood. Sorry that the shiny metal doesnít show up too well in the photo. Here Iíve begun carving small channels similar to the ones grubs cut in under bark. I used a Sharpie permanent marker to sketch in what Iím going to cut out. I only use this pattern as a general guide, and alter and add as I proceed. Not to be flippant, but the goal here is to cut away everything that doesnít look like rotten wood...really! Fortunately for us, the round burrs are absolutely ideal for channels of this shape - we donít have to deal with 90 degree corners here.
Here Iíve blued the area, so you can see it a lot better. I tend to blue as I go - it shows me how it will really look when finished. Thereís a remarkable difference in appearance between shiny metal and the final patinated results. Note how in the deeper areas Iím undercutting somewhat.
This is probably a good place to talk about another danger with the burrs and the grinder. You should not carve a channel in the metal that approaches half of the diameter of the burr in width AND depth. Less than half diameter in depth works fine, but when the burr begins to get crowded, a resonance can instantly occur which will cause the burr to go uncontrollable. The burr will likely be damaged, and the hole you are working in will suddenly and dramatically get MUCH larger. You can avoid this by making sure the hole/channel is significantly larger than the diameter of the burr. If you need to carve a very deep hole, use a burr that is significantly smaller than the hole, or carve the hole wider as half the diameter of the burr is approached. Close in size is VERY BAD!
Continuing on with more channels and holes. Note how some are shallow, some are deep, none are really circles but more irregular in shape. Also the deeper ones are undercut, and not going straight into the blade, but at angles away from the surface.
I want some of the holes (see the blue arrows) to go all the way through the blade and connect with the rotten wood on the other side, and some to be tunnels connecting with other holes. Rather than trying to carve all the way through (3/16 inch thick 5160 steel) I used a 1/8 inch drill bit and drill press to lengthen holes I already began cutting. Since these holes are now pretty circular looking, Iíll enlarge them and make them more irregular.
Finished with this side! Iíve added some rotting further down, and carved in several tunnels.
Here are the three tunnels - you can see the point of the tool in the other end. Areas like this add to the sense of hollowness by allowing light into the dark recesses.
Hereís the finished side. Iíve engraved three carpenter ants for a little more visual oomph. A good carving should tell a story, and there should be sufficient complexity that a piece wonít ďwear outĒ with little surprises for the viewer.
Above is an image of my Lindsay Palm Control engraver, and how I hold the Lindsay, for what thatís worth.. Itís a very compact but quite powerful air-driven system, and the control (how fast and how hard the internal piston hits the graver) is in the palm part. The harder you push, the more power the ďhammerĒ delivers - very responsive.
Basically I draw the ants on the steel, using a very sharp pointed nib pen and india ink, then engrave those lines using a 90 degree square graver in the Lindsay PC. All of this can be done using a simple hand held graver and hand held chasing hammer just as the old timers did for many past centuries (and some folks still do today).
Some bad news: Iíve tried the hand method with hand-made graver and hammer (you are on a knifemaker forum, so hammer and graver manufacture is certainly within your skill set). I can confidently say it will take a LOT of practice to get decent enough for your work to be seen in polite society. Conversely, I cut something fairly recognizable the very first time I used the Lindsay PC.
Thereís more bad news: this new generation of air powered engraving tools is quite costly, and needs support equipment like graver sharpeners and compressors, also not exactly cheap. The good news is they are significantly easier to learn than the traditional hand method. Lindsay has a new engraver, the Artisan, that is considerably less expensive than the Palm Control. It has a foot control, like the foot accelerator on your car, rather than the control on the handpiece. Probably a little less convenient than the Palm Control, but Iíve seen some very nice work done with them. Iíd love to have one as a second system, especially for stippling, but thatís another story.
If you want to learn more about engraving, visit these sites - itís how I learned to engrave:
Lindsay Engraver commercial and training site
Finally, here is the finished push dagger. While sharpening it today, I recalled why I swore off double edged knives - takes twice as long to sharpen them. Remind me to follow my own advice next time...
The engraved and carved copper scales are patinated with Birchwood Casey Super Blue. The engraving and carving on the scales is done exactly like the bark and wormy wood on the 5160 steel blade. The only difference is that the copper is, of course, much softer than steel, and in fact is a little bit ďgummy.Ē The carbide burrs tend to move (smear, maybe?) a little bit of the copper rather than cut it, leaving a little bit of flash sometimes. The flash is easily removed by trimming with the carbide burr from another angle.
Here is a test to find out whether your mission in life is complete. If you're alive, it isn't. Richard Bach
Posted 26 February 2009 - 10:32 AM
Posted 27 February 2009 - 03:34 PM
Here is a test to find out whether your mission in life is complete. If you're alive, it isn't. Richard Bach
Posted 08 March 2009 - 11:50 PM
I want to try to cut metal on the knife
There is another way of working with metal etching acid.
We have in Russia a little bad with the burrs .
Of course, after the acid you need to refine the burrs or cutters!
Posted 10 March 2009 - 09:00 PM
- Bruce Lee
"Drawing is the honesty of the art. There is no possibility of cheating. It is either good or bad. "
- Salvador Dali
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