Michael Pikula Posted January 5, 2009 Share Posted January 5, 2009 Hey guys, is the only way to protect a nonferrous inlay (I'll be using bronze and copper) in a pattern welded blade from etching/contaminating the acid to paint some resist on top of it with a steady hand and a small brush? Also so is it better to paint slightly over the edge of the inlay or as dead on as possible? Thanks Link to comment Share on other sites More sharing options...
GEzell Posted January 7, 2009 Share Posted January 7, 2009 That's a good question. Would it be possible to cut the channels, etch, then inlay? My concern would be etchant getting trapped inside/behind the inlay, that would be bad. Perhaps leave a panel containing the inlay unetched by masking it... A very light, mild etch with vinegar or lemon juice, just enough to bring color to the surface, but that would wear away quickly, or slowly be replaced by a natural patina with use... but it may work (I like a deep etch though). George Ezell, bladesmith" How much useful knowledge is lost by the scattered forms in which it is ushered to the world! How many solitary students spend half their lives in making discoveries which had been perfected a century before their time, for want of a condensed exhibition of what is known."Buffonview some of my work RelicForge on facebook Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 7, 2009 Author Share Posted January 7, 2009 That's a good question.Would it be possible to cut the channels, etch, then inlay? My concern would be etchant getting trapped inside/behind the inlay, that would be bad. Perhaps leave a panel containing the inlay unetched by masking it... A very light, mild etch with vinegar or lemon juice, just enough to bring color to the surface, but that would wear away quickly, or slowly be replaced by a natural patina with use... but it may work (I like a deep etch though). With the steel I am using I don't think that doing the inlay after the etch would work, since trying to push hardened L6/O1 down to trap the bronze isn't going to happen. I am planning on doing the inlay while the blade is still soft, then heat treat the blade, give it the final grind, then etch some how.... I was thinking maybe I'll try to paint resist just over the inlay then do my deep etch, remove the resist, give it a super short etch, just to get the pattern to start showing then a long soak in hot water with baking soda to make sure all the acid is gone. Another thought I had was to just leave a slight line of unetched metal around the inlay... I will have to do a sample to see if the etch line around the resist doesn't look out of place. I am with you on a nice deep etch! Link to comment Share on other sites More sharing options...
Doug Lester Posted January 7, 2009 Share Posted January 7, 2009 Michael, just an idea, engrave the channels for the enlay before etching and undercut the edge of the channel so that you aren't reliant upon pushing the edge of the steel over to hold the enlay. You might even undercut the channels after etching so as not to present a fine edge at the top of the channel to the etchant. If you don't have a power graver, you will probably have to use a hammer to drive the graver. Come to think of it, if you're engraving after hardening the steel you probably already have a power graver or are planning to drive a hand graver with a hammer anyway. Doug Lester HELP...I'm a twenty year old trapped in the body of an old man!!! Link to comment Share on other sites More sharing options...
Matt Bower Posted January 7, 2009 Share Posted January 7, 2009 I am truly spitballing here, but has anyone ever tried electro-etching (e.g., with salt water and a DC power supply) pattern welded steel? I ask because I think a steel blade would become a sacrificial anode and protect a bronze inlay from corrosion during electro-etching. But I could be wrong about that, and I don't know how well (if at all) electro-etching would develop the pattern. Link to comment Share on other sites More sharing options...
cdent Posted January 7, 2009 Share Posted January 7, 2009 Just wondering, if the inlay can survive heat treating the blade and finish grinding, does it need to be protected from the etch. Take care, Craig Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 7, 2009 Author Share Posted January 7, 2009 Hi Craig, The inlay should survive the heat treat since the melting temp of the inlay is a couple hundred degrees higher then the austenizing temp. This is something that Jody Samson told me about back when he was doing some inlay work. I will be heat treating in salts so I can get my preheat treat shape very close to my finished shape. I will leave about a mm edge thickness then I can clean up my surface with a finer belt, drop in my edge bevel, and good to go. Doug, I was thinking about doing inlay work after etching, but wouldn't the random hammer mark on the surface and the cleaning up of the surface of the inlay mess up the etch? From what I have seen inlays need to be cleaned up after being set so I don't know how practical it might be to do a "clean set inlay", But I could be very wrong. I don't have a power engraver, I was going to carve in the channel by hand, then raise up a small lip with a chisel and hammer. Interesting idea Matt, I might try to find a scrap piece of pattern weld laying around the shop and see if it works. Link to comment Share on other sites More sharing options...
Matt Bower Posted January 7, 2009 Share Posted January 7, 2009 (edited) It really seems like it should. Careful about the chlorine gas. Etching a whole blade probably will produce quite a bit more than just etching a small mark. Edited January 7, 2009 by Matt Bower Link to comment Share on other sites More sharing options...
McAhron Posted January 8, 2009 Share Posted January 8, 2009 Post the question at Hand Engraving Forums or the Engravers Cafe.Many of the worlds finest engravers hang there.I have never seen bronze inlayed as its so hard but just cause I've not seen it doesnt mean it cant be done. N'T McAhron Sqwaukin Vulture Verrinder "to create is to make art" TREMBLING EARTH KNIFE WORKS (website coming soon) Link to comment Share on other sites More sharing options...
B. Norris Posted January 8, 2009 Share Posted January 8, 2009 I will be heat treating in salts so I can get my preheat treat shape very close to my finished shape. I will leave about a mm edge thickness then I can clean up my surface with a finer belt, drop in my edge bevel, and good to go. That sounds like a great plan, the high temp salt will not let the inlay get overheated and melt. The only thing I would worry about is salt getting in between the steel and bronze during heat treat and then rusting its way out later. A good, looong, soak afterwards would be warranted. If you could get your hands on some de-ionized water, that would really do the trick. I suppose if the bronze was hammered in well, and thoroughly came into contact with the bottom and sides of the channel, it could be a non-issue. Another thought is to go over the bronze with a torch, after inlaying, until it becomes molten. You could flux the channel before inlaying the bronze and then torch it but, the flux might cause corrosion if it was not all displaced by the bronze. Hmmm... If it was me I would do up a test piece and try several different ways to see what worked best and to make sure the bronze made it through the high temp salts without problems. Of course, the benefit of this is that you get to be a guinea pig and report your findings to the rest of us! ~Bruce~ “All work is empty save when there is love, for work is love made visible.” Kahlil Gibran "It is easier to fight for one's principles than to live up to them." - Alfred Adler Link to comment Share on other sites More sharing options...
Simon Attwood Posted January 8, 2009 Share Posted January 8, 2009 a possible answer would be to use liquid latex over the inlay, but I'd do a test piece first. regarding the risk of salt and/or etch getting under the inlay and causing corrosion problems later on, I'd suggest a long (24 hrs +) soak in acetone after each process. "When our eyes see our hands doing the work of our hearts, the circle of Creation is completed inside us, the doors of our souls fly open and love steps forth to heal everything in sight." Â Michael Bridge Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 8, 2009 Author Share Posted January 8, 2009 I didn't even think about the corrosion issue if salts were to get trapped between the inlay and the steel... It's a good thing you guys did some thinking for me! I think a long water soak, and then an acetone soak should work well to get everything out. Bruce, I like your idea of going over the inlay with a torch to get it molten. I have tried Brazing inlays before but I couldn't get a nice thin line without getting little flux bubbles/pits. Fluxing, hammering in the inlay, then heating it could work rather nice. I will be sure to do a few test pieces and see what I get, I can also cut it up to look at the cross section of the inlay to spot any major problems. What would be a good way to jump start the corrosion process since the corrosion would start to be noticeable only after sometime, in the clients hands. Would soaking in salt water for a couple of days or so be a good way to go? Time to get to work! Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 25, 2009 Author Share Posted January 25, 2009 Hey guys, Thought I would post an update. So I inlayed one side and got a weld to open at the tip and one in the shoulder so it turns out I had the best test piece I could hope for. I didn't inlay the second side, I am going to do that later on this week so that I can compare pre heat treat and post heat treat effects, plus test more welds. I ground out the welds at the shoulder making the blade slightly shorter, and I am planning on cutting off the tip, making it shorter yet, but if no more welds break then I know everything else I got is solid! I just heat treated the blade and the crack at the tip didn't spread, however where the crack met the inlay the inlay came loose, other then that it looks pretty good, no melting or other kind of problems so far. It is tempering now so I can't do much but in an hour I will pull it out, cut off the tip, take some cross sections of the cut off inlay, and take the inlayed side up to 240 and post pictures of what I got. Later this week I'll inlay the other side and post progress as it comes along! Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 26, 2009 Author Share Posted January 26, 2009 (edited) So there really wasn't much to see from doing the cross sections except that my undercut really wasn't as "under" as I thought. Besides that the bronze stays in really good the way that I did it. I'm including a picture of what it looked out of heat treat. I found two little cracks between layer plus I realized that cutting the tip off would leave me with no mass at the tip so I decided to do some tests on it. I will post that in a seperate thread to keep things on topic. I'll still polish up a small section later on to see about protecting and blending the finish. Edited January 26, 2009 by Michael Pikula Link to comment Share on other sites More sharing options...
Alan Longmire Posted January 26, 2009 Share Posted January 26, 2009 Wow, that's a nice blade! I see what you're trying to do now, was having difficulty visualizing it at first. As an aside, I have a book about gas welding and brazing in which the author says not to braze some alloys, specifically 4140 tubing, because the brass can cause intergranular cracking that won't show up until stressed. I wonder if that has something to do with your delamination issues on this blade? Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 26, 2009 Author Share Posted January 26, 2009 Wow, that's a nice blade! I see what you're trying to do now, was having difficulty visualizing it at first. As an aside, I have a book about gas welding and brazing in which the author says not to braze some alloys, specifically 4140 tubing, because the brass can cause intergranular cracking that won't show up until stressed. I wonder if that has something to do with your delamination issues on this blade? It WAS a nice blade!!! hahaha, I'll be grinding the replacement today so hopefully by the end of the week I'll have a finished blade that is done right. That is interesting about brass causing intergranular cracking.... could it be the way that the brass fuses with the bonding metal plus the grain growth from the act of brazing? I don't know if this would apply to my problem, I think it was just me hammering on bad welds. Link to comment Share on other sites More sharing options...
Alan Longmire Posted January 26, 2009 Share Posted January 26, 2009 That is interesting about brass causing intergranular cracking.... could it be the way that the brass fuses with the bonding metal plus the grain growth from the act of brazing? I don't know if this would apply to my problem, I think it was just me hammering on bad welds. After seeing your other thread I think you're right. Darn it! That blade shape is next on my plate, and I can only hope mine ends up looking as nice as yours. I think the way way the brass thing works has to do with the low-alloy Cr-Mo steel. The idea as I recall was that the brass could actually penetrate intergranular boundaries through capillary action, leading to a fracture-prone structure. Since that is kind of how brazing works, it could have some merit. I don't know why the guy specified 4140 tubing only, though. He was perfectly happy brazing mild steel gas tank brackets onto an old Corvair. I have never had any problems with pipe hawk bowls cracking off when brazed, and most of mine are mild steel tubing. Under magnification you can see some intergranular penetration, though. Maybe the 4140 tubing air hardens a bit or something. Idle speculation on my part, didn't mean to hijack the thread. Link to comment Share on other sites More sharing options...
jake cleland Posted January 27, 2009 Share Posted January 27, 2009 man that blade was going to be beautiful. did the fuller on the top one strt out like that of the one below it, and taper during the grinding? Jake Cleland - Skye Knives www.knifemaker.co.uk "We can't solve problems by using the same kind of thinking we used when we created them." "Everything should be made as simple as possible, but not simpler." "Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe." Albert Einstein Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 27, 2009 Author Share Posted January 27, 2009 So I have been doing a lot of thinking so as not to screw up my next blade and have decided to do the inlay after I heat treat and after I am done with my 120 grit, then go back with the 120 for a touch up of the inlay. I have come up with this order for several reasons, most of then obvious but none the less here they are: * I would rather have hard or half hard inlay rather then annealed inlay * The amount of flex that I might have to do to correct a warp might very well screw up the inlay by contracting one side and pulling on the other * I frequently drip the blade in low temp salts to correct warps, this would lead to way to many long soaks and possibilities for salts to get stuck in the channel * I had a dream that I did it that way and it worked just fine Ok, there is not logical reason why the last reason is valid but the first three are more then enough! Also I have decided to cut my channel in with the flex shaft machine and a .030 cutting wheel, then put a slight fish tail on my inlay wire to ensure a really nice lock, plus this decrease the pressure needed to lock in the inlay, and I can set both sides, then when I hammer them home I am applying force to only the inlay on both sides and reducing stress on the blade itself, or so it would seem logical. Still have to do my test strip for the etch, that will be coming shortly! After seeing your other thread I think you're right. Darn it! That blade shape is next on my plate, and I can only hope mine ends up looking as nice as yours. Thanks Alan, I have blade attempt #1 done and will be working on the hilt this week, I hope to have it done by wednesday.... if I am lucky, I'll post pics as soon as I can. It is the shorter one on the stool in the post heat treat pre RIP stage. If all goes well I hope to have blade attempt #3 done this week, but I have to hold of on pictures until I get the handle done and my customer takes delivery. But I'll be sure to post progress notes. Link to comment Share on other sites More sharing options...
Michael Pikula Posted January 27, 2009 Author Share Posted January 27, 2009 (edited) man that blade was going to be beautiful. did the fuller on the top one strt out like that of the one below it, and taper during the grinding? Hi Jake, Yes, that is how I cut in my rough fullers, then as I move through my grits I fade the tips out a little at a time. The bottom blade is done and I'll post pics as soon as I get the blade mounted. Best, Michael Pikula Edited January 27, 2009 by Michael Pikula Link to comment Share on other sites More sharing options...
guarnera Posted January 27, 2009 Share Posted January 27, 2009 That sounds like a great plan, the high temp salt will not let the inlay get overheated and melt. The only thing I would worry about is salt getting in between the steel and bronze during heat treat and then rusting its way out later. A good, looong, soak afterwards would be warranted. If you could get your hands on some de-ionized water, that would really do the trick. I suppose if the bronze was hammered in well, and thoroughly came into contact with the bottom and sides of the channel, it could be a non-issue. Another thought is to go over the bronze with a torch, after inlaying, until it becomes molten. You could flux the channel before inlaying the bronze and then torch it but, the flux might cause corrosion if it was not all displaced by the bronze. Hmmm... If it was me I would do up a test piece and try several different ways to see what worked best and to make sure the bronze made it through the high temp salts without problems. Of course, the benefit of this is that you get to be a guinea pig and report your findings to the rest of us! ~Bruce~ Brownells has stuff for getting all the bluing salts out of tight places that it might get stuck in. This might help to get any H.T. salt out off anyplace it might get into. Tony G P.S. You could solve this problem the easy way, by using gold for the inlay. That's a joke. Link to comment Share on other sites More sharing options...
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