Roger Keagle Posted March 2, 2007 Share Posted March 2, 2007 I have a question, does any one kow how to do "Popcorn surface" as seen on many Japanese tools ? Quote Link to comment Share on other sites More sharing options...
Glenn Posted March 2, 2007 Share Posted March 2, 2007 Roger, do you have any photos of the finish? Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted March 2, 2007 Share Posted March 2, 2007 As I recently learned, it is probably the effect of spot carburization. When heating and heat treating in a coal or charcoal forge, the places on the steel that are in direct contact with the fuel carburize, and the places not in direct contact with the fuel decarburize. It's what SOME people MAY call a blister effect. There will be lots of small raised round dots varying in size. I've seen some probably 3/4 the diameter of a dime. Quote Link to comment Share on other sites More sharing options...
Roger Keagle Posted March 2, 2007 Author Share Posted March 2, 2007 I believe Tyler is on the right track, all of what I have learned so far seems to point in this direction. Not sure is we can do the surface using Western alloys of steel...does any one know more ? THis has been a great help so far, I will try and find a pic for example. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted March 2, 2007 Share Posted March 2, 2007 Probably similar to what you see in color case hardening. Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted March 3, 2007 Share Posted March 3, 2007 I no longer heat treat directly in contact with the fuel, so I can't tell you what steels it will definately work with, BUT, any steel will decarburize and carburize, thus it should work with any steel, BUT some steels are more resistant to decarb. I believe O-1 is one of them, off the top of my head. Quote Link to comment Share on other sites More sharing options...
Roger Keagle Posted March 3, 2007 Author Share Posted March 3, 2007 First I know it is noting like case hardening, and I have done that. The surface is disrupted like it had been selectivly been burned away...still trying to find a good pic, that will help I think. Quote Link to comment Share on other sites More sharing options...
Roger Keagle Posted March 3, 2007 Author Share Posted March 3, 2007 Found a fair shot of an old plane blade with the surface I an trying to make...Japanese woodworking plane Tsunesaburo Quote Link to comment Share on other sites More sharing options...
clark-kentski Posted March 3, 2007 Share Posted March 3, 2007 Looks like he used acid since even his touch marks are effected,or he tossed some metal filings on his anvil and worked the hot piece on top,easy enough to try!Then again maybe your thinking of a japan finish like you see on old binoculars and such thats like a black crinkle paint.:confused: Quote Link to comment Share on other sites More sharing options...
skunkriv Posted March 3, 2007 Share Posted March 3, 2007 Not sure if this will give you what you want but I have seen a method of forge texturing demonstrated by George Dixon. He heats his piece in the forge and lets it scale real good then picks off spots of the scale with his fire pick and scales some more, picks some more, repeat and repeat and repeat..... His finished piece did not have as fine of texture as the piece you showed but if you carried it to an extreme (repeat, repeat etc.) I don't know. This would involve some major grain growth in any tool steel which would require grain refining heat cycling for sure. George was using it for decorative pieces. Nice effect when the textured piece is stacked behind a pierced piece overlay. I think I have seen him do this in both gas and coal forges. Am guessing it might be a little quicker and easier to control (see) in a coal forge heating the piece hard from underneath and leaving the top surface exposed to the air. Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted March 3, 2007 Share Posted March 3, 2007 The surface of that plane blade looks a lot like the surface of bloomery made iron as it is compacted. There are a lot of impurities in the iron and it must be forged to fully consolidate it and drive out the inclusions. The smith who made that blade clearly saw the texture as aesthetically pleasing and did not remove it. Or not. Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted March 3, 2007 Share Posted March 3, 2007 The surface of that plane doesn't look like what I was talking about. Quote Link to comment Share on other sites More sharing options...
oakwoodforge Posted March 4, 2007 Share Posted March 4, 2007 Roger, One of my blacksmithing teachers, Yataiki ( Miyano dai Endo) had a hammer with a randomly textured face that I think was for making finishes like this. Wish I spoke better Japanese, I Might have a better answer for you if I did. Jens Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted March 4, 2007 Share Posted March 4, 2007 By Tai Goo Quote Link to comment Share on other sites More sharing options...
Tyler Murch Posted March 4, 2007 Share Posted March 4, 2007 Better pic of the texture. The hammer he uses to give it this texture can be seen in the link in my previous post. Quote Link to comment Share on other sites More sharing options...
Roger Keagle Posted March 4, 2007 Author Share Posted March 4, 2007 Yep, some more food for thought, again, thanks for the input guys ! For one thing, I know the finish is NOT crinkle paint ! The example I showed is at least 100 years old, and more than likly older...I am not any expert in such. Saw some older Japanese tools at a show in Melbourne and they really impressed me...the surfase gave a good grip besides looking good, and contrasted well with the highly polished cutting surface. I noted a harmon line where the edge had been tempered so perhaps the method suggested by Skumkriv might be close to what I am seeking. I use a coal forge so scale is not a problem, sweep up heaps of it after every firing.. SMILING....Trust Tai Goo to invent a wacker...this also has merit, and perhaps is combined with other things could get the desired result...guess you guys know what I will be doing on the next few cool days here in Oz (Thats short for Australia) Quote Link to comment Share on other sites More sharing options...
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