Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
Moderator
Knifemaker / Craftsman / Service Provider
- Joined
- Aug 20, 2004
- Messages
- 38,521
The light is starting to shine now.
It makes me happy to see the thread move toward an understanding of what causes something, not just how to do it.
Indeed, the clay thickness. and the mass of the steel are the key elements of placing a hamon.
Here is more info on my procedure:
After all normalizing and spheroidizing,I sand the blade to 220-400 grit. I leave a fairly thick edge, somewhere between .030-.040" . I leave extra niku (meat) in the blade bevels to take out in the final sanding.I wash the blade well and dry it. I coat the blade with a thin wash of satanite and dry it with a hair dryer. I then add more satanite to the mix to make it like thick cake batter. It should be thick enough not to flow easily, but not too stiff. I put about 1/8" of this over the blade surface (I do one side at a time). I then strike off the ha (edge) with the side of my thumb. If all this is done fairly quickly, the dried thin wash still remains ( if not, no worry). If you quit here, you will have a suguha hamon (more or less straight line). If you shape the clay rim to get the desired pattern, you can get many more elaborate patterns. I add ashi lines of thinned clay to the ha surfaces usually. These are just little lines made in a sort of "X" pattern going from the thicker clay across the ha right to the edge. They greatly improve the look of the hamon, and I believe aid in preventing breakage in quench. I use a popsicle stick to tap them all over the edge. Dip the stick in the thin clay and tap it gently to the , lifting immediately. Just enough clay will transfer to leave a little ridge of clay running from the thicker clayed spine area to the edge.Once one side is done and dried with the hair dryer, do the other side. While you want the sides to match pretty closely, it is not so much important that the two sides are mirror images as it is that the distance from the edge is maintained.
The following is done in a shady smithy and often at night:
I set up the quench tank and warm the oil. I clear everything flammable out of the way and blow out all the leaves ( often a big task in my smithy). I have a wooden mallet and a brass hammer sitting by the anvil. All things needed are ready (you won't be able to stop and go get a rag later).
Once the clay is well dried, I warm the blade in front of the forge. ( I usually do these blades in the forge by eye and magnet, but the oven is a good choice if it is big enough ,swords don't fit mine). After the clay is well cured, I start the heating in the forge.I have already set the forge to run at about the desired temperature, somewhere around 1500F, and allowed it to fully heat up (about 15 minutes). I set the blade in the forge ,edge down, and usually keep it moving back and forth (in and out of the back port for longer blades).As the blade heats up I watch for the areas that heat up faster. I speed up the push-pull in these areas. When the blade is evenly red, i check with the magnet. As it crosses the Curie point (non-magnetic) the blade edge will start to have shadows run across it. I keep heating until the color becomes constant and appears to be about 100-150F higher that the transformation point. At this point the blade should be well soaked and about 1450-1500F.
Before I started the quench, i did several practice "quenches" with an unheated bar of steel to make sure I had the tank and everything in the proper places. I feel this is important, because many bad quench results can come from a slight hesitation during the quench. It need to go into the tank quickly, smoothly, and in one stroke. Don't be in a rush to "stab" the blade into the oil, just a smooth even quench. As always, the tank should be secure and non-tippable..... you don't want several gallons of flaming oil running across the floor.
Back to the heated blade - When all is ready to quench, i pull the blade out and in one smooth motion run it point first straight into the tank. I don't move it at all once it is in. I say (out loud) One, Two, Three, and pull the blade straight out of the tank. Be prepared. It will burst into a flaming ball. Don't panic, it will be fine. I count again One, Two, Three, and plunge it back into the tank. The oil will snuff out the flames shortly. ( A trick here is to put a layer of CO-2 on the top of the oil (the oil level should always be about 3-4 inches below the rim anyway). A squirt with a CO-2 extinguisher, or a chip of dry ice dropped in will do the trick. This makes the flare up much less) Move the blade up and down in the tank and from spine to edge (never sideways), to speed up the final cooling. After about 5-8 seconds pull it out,run a forge scraper along the blade to knock off the clay.Wipe it off with a rag (be careful, it is still very hot!) quickly check for warps or twists, and place on the anvil,and pound out any that are there (or use gloved hands). If the blade starts to feel stiff....quit straightening. Place back in the tank to cool .Pull out and give a quick rub down with 220-320 wet-or-dry. If the hamon looks like it will be acceptable, clean up a bit more, temper, sand, etch, finish, etc. If it is not right, wash the blade and re-clay it.
Final tip:
The rag used to wipe down a hot blade will often catch fire. While we all have a metal can close by to drop flaming things into (you don't?), a fire proofed rag is a good idea. Take a piece of cotton cloth or toweling, and soak it in a hot solution of water and borax (20 mule team is fine). Take it out and wring it . Let it dry. The cloth will greatly resist catching fire now. It will still scorch and all, but won't flame.
Hope this all helps.
Stacy
It makes me happy to see the thread move toward an understanding of what causes something, not just how to do it.
Indeed, the clay thickness. and the mass of the steel are the key elements of placing a hamon.
Here is more info on my procedure:
After all normalizing and spheroidizing,I sand the blade to 220-400 grit. I leave a fairly thick edge, somewhere between .030-.040" . I leave extra niku (meat) in the blade bevels to take out in the final sanding.I wash the blade well and dry it. I coat the blade with a thin wash of satanite and dry it with a hair dryer. I then add more satanite to the mix to make it like thick cake batter. It should be thick enough not to flow easily, but not too stiff. I put about 1/8" of this over the blade surface (I do one side at a time). I then strike off the ha (edge) with the side of my thumb. If all this is done fairly quickly, the dried thin wash still remains ( if not, no worry). If you quit here, you will have a suguha hamon (more or less straight line). If you shape the clay rim to get the desired pattern, you can get many more elaborate patterns. I add ashi lines of thinned clay to the ha surfaces usually. These are just little lines made in a sort of "X" pattern going from the thicker clay across the ha right to the edge. They greatly improve the look of the hamon, and I believe aid in preventing breakage in quench. I use a popsicle stick to tap them all over the edge. Dip the stick in the thin clay and tap it gently to the , lifting immediately. Just enough clay will transfer to leave a little ridge of clay running from the thicker clayed spine area to the edge.Once one side is done and dried with the hair dryer, do the other side. While you want the sides to match pretty closely, it is not so much important that the two sides are mirror images as it is that the distance from the edge is maintained.
The following is done in a shady smithy and often at night:
I set up the quench tank and warm the oil. I clear everything flammable out of the way and blow out all the leaves ( often a big task in my smithy). I have a wooden mallet and a brass hammer sitting by the anvil. All things needed are ready (you won't be able to stop and go get a rag later).
Once the clay is well dried, I warm the blade in front of the forge. ( I usually do these blades in the forge by eye and magnet, but the oven is a good choice if it is big enough ,swords don't fit mine). After the clay is well cured, I start the heating in the forge.I have already set the forge to run at about the desired temperature, somewhere around 1500F, and allowed it to fully heat up (about 15 minutes). I set the blade in the forge ,edge down, and usually keep it moving back and forth (in and out of the back port for longer blades).As the blade heats up I watch for the areas that heat up faster. I speed up the push-pull in these areas. When the blade is evenly red, i check with the magnet. As it crosses the Curie point (non-magnetic) the blade edge will start to have shadows run across it. I keep heating until the color becomes constant and appears to be about 100-150F higher that the transformation point. At this point the blade should be well soaked and about 1450-1500F.
Before I started the quench, i did several practice "quenches" with an unheated bar of steel to make sure I had the tank and everything in the proper places. I feel this is important, because many bad quench results can come from a slight hesitation during the quench. It need to go into the tank quickly, smoothly, and in one stroke. Don't be in a rush to "stab" the blade into the oil, just a smooth even quench. As always, the tank should be secure and non-tippable..... you don't want several gallons of flaming oil running across the floor.
Back to the heated blade - When all is ready to quench, i pull the blade out and in one smooth motion run it point first straight into the tank. I don't move it at all once it is in. I say (out loud) One, Two, Three, and pull the blade straight out of the tank. Be prepared. It will burst into a flaming ball. Don't panic, it will be fine. I count again One, Two, Three, and plunge it back into the tank. The oil will snuff out the flames shortly. ( A trick here is to put a layer of CO-2 on the top of the oil (the oil level should always be about 3-4 inches below the rim anyway). A squirt with a CO-2 extinguisher, or a chip of dry ice dropped in will do the trick. This makes the flare up much less) Move the blade up and down in the tank and from spine to edge (never sideways), to speed up the final cooling. After about 5-8 seconds pull it out,run a forge scraper along the blade to knock off the clay.Wipe it off with a rag (be careful, it is still very hot!) quickly check for warps or twists, and place on the anvil,and pound out any that are there (or use gloved hands). If the blade starts to feel stiff....quit straightening. Place back in the tank to cool .Pull out and give a quick rub down with 220-320 wet-or-dry. If the hamon looks like it will be acceptable, clean up a bit more, temper, sand, etch, finish, etc. If it is not right, wash the blade and re-clay it.
Final tip:
The rag used to wipe down a hot blade will often catch fire. While we all have a metal can close by to drop flaming things into (you don't?), a fire proofed rag is a good idea. Take a piece of cotton cloth or toweling, and soak it in a hot solution of water and borax (20 mule team is fine). Take it out and wring it . Let it dry. The cloth will greatly resist catching fire now. It will still scorch and all, but won't flame.
Hope this all helps.
Stacy
