evfreek

Hi Thomas. Yes, I understand the mottling effect of low layer count billets. Actually, I was going for that look. But, what I did not like was the different etch amounts within each different steel. I now realize that it was a combination of two effects. Wrong steel and too fast. The muriatic acid did a better job, as it was much slower (few hours). The ferric chloride started well, but started to lose differentiation after about 10 or 15 minutes. Next time I will dilute it more. Maybe I will try to weld up the remaining bimetal blades, but hotter, and with a more aggressive flux. Also with the pallet strapping cleaned better. Another thing I had problems with was excessive tapering of the knife point. That caused delaminations and loss of pattern. I would have been better off just grinding.

Hi Jens, Rich, Thomas and Chuck. Thanks for all the good information. It is really helpful. These were some scrap bandsaw blades that I retrieved from a fab shop which was relocating. I was hoping to use these for hacksaw blades, but they proved to be too slow cutting. Probably need a broken or stripped blade for this, otherwise it may prove to be dull. The blade that I saw on Ebay was 1.5" wide. Not nearly up to the 6" that Thomas and Chuck mentioned. I suspect that it will be easier to just order 15N20, since that will cost less than hunting around. I would like to use up the old blades that I have, but if they are poisonous to grind, they may not be of much use. Also, the pallet strapping is only medium carbon. Definitely not 70 points according to a spark test. More like 40-50. Also, I did not clean the coating or remove the bandsaw blade teeth. I tried two etchants: 1/3 strength muriatic acid and full strength Radio Shack PCB etchant (ferric chloride). Both produced mediocre results. The acid was slower, but it seemed to give a nicer looking pattern. Unfortunately, it was uneven. In otherwords, it produced a mottled pattern on both types of steel, with the contrast of the mottling similar to that between the different steels. Perhaps I should try a diluted solution of the ferric chloride and let it sit for longer. Next hammer-in I go to, I'll search for the mono steel wide bandsaw blade. I will need to calibrate my eye for the nickel alloy sparks, since I don't know what to look for yet. I hate to waste the old metal cutting bandsaw blade that I have now, but maybe it will be good for shop knives. Thanks again. This stuff is tricky.

Hi. I tried to weld a billet out of pallet strapping and old dull bandsaw blades. There were a lot of inclusions in the final billet, and I noticed that the etch did not attack the pallet strapping and the bandsaw blades all that differently. It was possible to see the layers, but the difference was not all that stark. Perhaps they were the wrong kind of bandsaw blade? They came from the scrap bin in a metal fabrication shop. They were about 1" wide, and 10 tpi. A spark test showed the teeth were a different material than the rest of the blade. The teeth sparked like a tungsten high speed steel, and the bulk of the blade as medium carbon. The blades were hard to shear. I have read that the correct nickel bearing blade material is found on sawmill wood bandsaw blades. There was one offering on Ebay of "knife bandsaw blade". It looked iffy, since the seller said that they were normally $12. Is this a reasonable price for half a dozen 10" lengths? I don't think so. Do the blades have to be above a certain width? I cannot seem to find the really wide ones (4-6"). Could these be what is required?

Hi Hillbillysmith. Some touch-up with a stick welder really helps out that RR track for use as an anvil. I have found that those track plates do not really have useful holes, since they are kind of the wrong size and are in the wrong places. I tried to cut a 1" hole in one, but it was a Pyhrric victory. Too difficult for the gain. Much better to go for Mike-HR's portable hardy hole design (given in the BP's). You are handy with a welder, and that is a great application. The main weakness of a RR track anvil is that the edges are not very useful. There is too little support by the relatively thin web. There are two ways to work around this problem. One was given above by acoop101. Bolster the sides or weld two rails together side by side. Another is to use the vertical rail idea. This really improves the edge rigidity, since the foot or web is used as the edge, and it is supported all the way down to the ground. There is some guy who shows up at blacksmithing conferences who pieces anvils together with junk steel and an arc welder. It does work. If you don't use the edge of the anvil, I guess that it does not matter that much.

Hmmmmmm. "a good hammering cherry red (800 F, 430 C) in 20 minutes" Even in well-regarded refereed journals, misstatements such as these weaken the credibility of the article. I would not commit a few thousand dollars to build a prototype after seeing these figures in the plans. I think that when I was beginning, one of my problems was not getting the metal hot enough. But this is ridiculous. First, 800F is not "cherry red". I cannot see 800F reliably, not even at night. And I have a pyrometer. Second, "cherry red" is not "good hammering". "Good hammering" is light orange or yellow (2000F +). Again, these are my preferences, and some smiths may prefer cooler, but not that cold.

Hi. I just took a tour of the Techshop in Menlo Park, CA a few weeks ago. The tour guide was very enthusiastic. The concept has been proved by the pilot and is considered very successful. That is the reason for the expansion. The website is a little out of date. The Marin expansion is on indefinite hold due to personnel reasons. Also, the Menlo Park site will be relocated in the next 18 months to a larger site, since they are bursting at the seams with tools. That place is packed!!!! But, as pointed out above, no power hammer. To tell you the truth, the corporate district that they are currently located in is not really an appropriate location for a power hammer. My smithy is an appropriate location for a power hammer. But not for a Bridgeport mill or a laser engraver. As for the question about consumables, currently they are provided at no extra charge. When we toured the stockroom, nearly all the hard consumables were from Harbor Freight. If I ever worked in there, I would bring my own grinding disks/belts. It is not worth the inefficiency. Sure, Harbor Freight is cheap, but some of their abrasives are not worth the risk/slowdown. I especially made sure to ask the tour guide about gas. I know how much gas a goofball can blow through in one night. (By experience: I visited another co-op and saw a couple of greedy, inconsiderate, self-important gas hogs blow through $50-100 of gas.) Currently, there is no extra charge. Oddly enough, I did not see any gas hogs during the tour, although they only had one small Lincoln Precision Tig 175 there. Nobody was using it. There was one fellow using the Oxy-Ac torch, but the wasn't a hog. I do not have a problem with the $40 (used to be $30) that they charge for the "lessons". This is more like certification, since you cannot learn much aluminum TIG in one hour with a bunch of other classmates. You will learn what the switches mean and how to grind a tung. All in all, I believe that the Techshop is a great idea. At the urging of a fellow blacksmith, I once signed up for a co-op like this, since he said that it would "round out" my metalworking skills. It was a wonderful experience and a great deal, and I met some truly rotten people who I would never want to see again. I also decided that I do not want to be well-rounded. I want to be a better blacksmith. And I have a really long way to go still.

Magnet trick, then heat a little bit longer. OK, I realize that it is not that great, but I cannot see recalesense (sp?) very well. And the magnet trick works just fine for heat treating chisels. Should I have used a tempilstik?

HWooldridge, you are absolutely right about that. Do not use a mixture with a faster flame front in a tip designed for a slower one (within sensible limits; I have a couple of acetylene/propane National tips, but you crank up the flow for acetylene). A couple of years ago at a CBA conference, someone connected a MAPP tank to a propane rosebud. Ran OK until it got hot enough to flashback, then BOOM. The tip was about the size of a D flashlight battery and cost about $200. It looked like a gun that Elmer Fudd fired without realizing that a bunny had stuffed a carrot in the end. One of the fellas said that he was sure glad that he wasn't the one who goofed the tip. I didn't get a chance to speak with the victim, but it must have been spectacular. I heard that you could use MAPP gas in an acetylene one piece cutting tip, but propane would not work. One fellow who tried the propane confirmed this. The article also pointed out that this is only as a last resort. The use of the correct tip would save more than the cost savings from not buying another tip in pretty short order. Since this thread was posted, I looked around on the WWW for a propane rosebud for my torch. I could only find large ones that required over 600 cfh of oxygen to operate . And, they are expensive. If I ever need to do larger scale heating, I will use a propane cutting torch tip. Or, a venturi burner and a pile of firebricks. I've heard that this works pretty well. As for all the other tips, they are cheap enough so that I will just buy them at the welding store. But not the rosebuds, so I understand why the question was being asked.

Hi Matt. It was about 100F. Just warm. About 7% brine. Maybe it was too warm.

Hi. I came upon this interesting link. Heat Treatment To summarize, the document advocates quenching in brine, interrupting the quench at 900F (no color), air cooling, then slow cooling from 400F or so on down. I tried this, and was not able to get my steel to harden (pallet strapping and bandsaw blade). The alloy is hardenable, as the pallet strapping tested out at about 50-60 points of carbon (not 1095!!!!). Interestingly enough, when I annealed the steel in ashes (dead soft), there was a hard spot where the tongs gripped it. According to the explanations and the TTT diagram, the technique should work. It is very similar to marquenching or Intensiquenching. Has anybody had any experience with this technique, either positive or negative. :confused: Thanks!

Hi Dr. Dean. Dr. Seuss is pretty funny, but I wouldn't trust him for building electronics equipment I guess that I need to put a front panel and terminal block on that thing. But, if you are looking at it and trying to decide, decent panel or copper bracelet, the bracelet wins. I think that the next thing it is calling out for is a foot pedal. I just bought a bench shear. It works great and I look forward to using it. Maybe this will be good for fabbing a foot pedal. Just some string and a little slide. Weld it up with the homemade TIG. Should be good. I really miss the foot pedal on thin stuff, so that might come before the lugs and decent cables. Good thing I'm in no hurry ;)

Hi Glen. I think that this is a great idea. I will give it a try. By the way, conductances add, so this will always lower the resistance. For example, adding pipes to a network (fully developed flow) always improves the rate. Note that this does not apply for incompletely developed flows, for example, adding extra inlets to a naturally aspirated burner. The arc blow problem is a valid one. Still worth a try.

Spark test and use crumbles for forge hardfacing?

Hi. I think that from the standpoint of fabrication, there are no standard engineering practices that involve welding to high strength bolts. It is just a tacky thing to do . (Sorry about that; I really am.) Still, I have done it in situations which call for a hack. One example is for a quick and dirty bending fork. The high strength bolts are substantially more resistant to bending. Tom Clark uses 1050, and that works pretty well. A lot of these high strength bolts are something similar, or have some CrMo in them. Might be able to see this in a spark test. Don't count on it unless you are an expert. Normal HSLA rules apply. Select the welding rod (I use 10018, lo hy is important). Preheat. Peen (maybe). Overweld and grind the last layer of weld off. There are cold welding compounds given in some of the old machinist reference texts. They act like the opposite of never-seize, and can be thought of as "always-seize". They usually contain some sort of acid, and will create corrosion in the joint. For bolts, they are as strong as welding, and the bolt will fail first if you try to turn it. I am not recommending this, and I have never tried it, but it is something to think about. I would be afraid of corrosion induced stress cracking.

Hi woodwalker. You need to find a fellow high school chemistry student who knows how to do a heat of reaction/fusion balance. 1/8 t of each ingredient will not sever a 1/2" thick angle iron. Plus, thermite is better for demolition than cutting. In our high school chemistry class, the instructor set a few teaspoons on fire. It was not enough to melt through lab tweezers, but it did melt the tool into the blob, rendering it useless. Demolition, not cutting. As for igniting it, you need finer ground mixtures and more of it. Also, if you are in GA, you can probably get ignitacord. This stuff burns HOT! That's because one if the ingredients is thermite. And it lights easily. You can even light it with hammer and anvil. As for your angle iron and hot cutting it, don't mess with the forge. Ground fire. Search the blacksmithin' forum for the phrase. It will get you out of jams with the big stuff.

This is an excellent price for coal. Lazzari's (from the ABANA coal scuttle list) just raised their prices to $23 for a 50# bag. This is excessive . Any lower cost alternatives for California (bay area)?

Hi Dr. Dean. Here are the pics you requested . The arc starter is not homemade, but the welder is made out of an old microwave oven. GE Spacesaver, I believe :cool:

Hi Dr. Dean. Thanks for the compliment. My buddy who is into small stuff turned me on to this design. He swore off the big stuff after I passed off a 7/8" S-7 bar to him to break down into a knife. The welder I used to do the ends of the bracelet is my homemade microwave oven welder. It uses the frame, rewound transformer, bypass capacitor, fan and plug from the oven. I "borrowed" an arc starter from a real TIG welder. I have a paper bag containing a high current isolated triac, a diac, and a sheet aluminum heatsink. I need to fab up a foot pedal. Right now, I am working out the bang-bang to make sure I don't skip cycle or glitch. Also, I need to size the potentiometer, since a lot of these designs sink a lot of power (like the Miller pedal).

Hi Dan. No slight intended. I just wanted to point out that the masses do not add, even if the contact is pretty good. If you have ever tried cutting over a plate, it subtracts, rather than adds to the rigidity of the anvil. Try cutting out a complex shape in hot 1/8 or 1/4 plate with a chisel, and you will have plenty of time to think about this observation. As for the possibility of damaging the anvil, the theory behind a heavier anvil is that, for an elastic collision, more of the energy goes back into the hammer, so less is available to damage the anvil. My suspicion is that anvils get damaged by getting their faces gouged up and swaybacked, as well as getting the edges chipped. Adding mass around the bottom might not help as much as changing the shape to the blocky one associated with the larger anvil. This is more guesswork than experience. I only sledge on the big anvil at the farm, and it is more damaged than the small one, mostly because the face is softer. One day an old man came by and said that he used that big anvil 70 years ago, and it was old at that time. I have never chipped an anvil, nor have I put a swayback in one. But, I did see a striker knock a chip out a fairly large (300 lb) anvil. It was scary. I have this funny feeling that it would not have helped to have a big plate under that anvil. But it may have helped if the plate were on top :)

Here are some pics of the bracelet:

Hi James. Thanks for the tip. And others about the flux. The copper fused well without flux. I like the idea about the nearby plate, or just a sacrificial welding table like HWooldridge's (I just bought one of those; if it gets goofed up, I will just get another.) I used scrap Romex as filler. It seems to work. The key for me was to keep the bundle of strands together (with another copper wire). If one gets loose, it is like the weak animal which falls behind. It gets eaten by the mountain lion My welder does not have a foot pedal. I really need to get one. Maybe that's my next project. Or is it a guillotine tool. Or is it a new slitter, or shear or ... :D

Last night I tried welding copper with TIG. I did not use any flux. Would brazing flux help? The project was the one on Ron Reil's www pages: Gallery Making Copper Wire Bracelets The process was not very controllable, and I was successful only by striking an arc, then immediately stopping as soon as I saw a shimmer. The welds ended up looking pretty clean, but the copper dripping off got oxidized pretty badly. Does one commonly use a paste flux? My welding books don't seem to cover copper. Only steel, stainless, aluminum and titanium. No flux.

Hi Dan. Before trying to beef up the apparent mass of your anvil, try to get a little more blacksmithing experience. One experience that I highly recommend is doing some hot cutting with a chisel on the top of a cutting plate, which protects your anvil face. You will notice a lot of noise and slop between the plate and the top of your anvil. That should give you an idea about how the masses add. The plate weighs about 1 pound, and it is much better with the anvil than without it, so there is some additive effect, but the combination of the two is less than their sum, and probably even less than just the mass of the anvil. It is hard to communicate. You will understand exactly what I mean after you do it a few (dozen) times.

Hi John, and others. I just got some time at the forge, and made a set of 1/2" Poz tongs. The fork and isolated bending heat really cleans things up, but I still did not get the bends quite right. I located the fuller marks with soapstone (which disappeared) and nicks on the edge of the anvil. The problem is that the isolation of the heat determines the curve of the jaws. So, if making the tong ends on opposite sides of the bar (to avoid using tongs), it is difficult to make them exactly the same. Also, the second taper is hard to get quite right. It does not go all the way through the length of the section, but rather ends about half way. This affects the length of the jaw and the width of the boss, two very important dimensions. As for the EC I mentioned above, Ron Reil's site is correct. Unlike the original instructions, the fullers should be on opposite sides of the bar. The first fuller is the inside of jaw curve, and the second fuller is the offset of the handle on the inside. So, both fullers face in across the rivet. Therefore, they must be on opposite sides. Also, there is a slight error in the dimensions. It is better to use the overall length in the drawing and not the text. 7" going from 5/8" down to 1/4" will more than double the length of 1" stock when drawn, by volumetrics.

Hi. I have been having a lot of trouble with creating clean bends on tong jaws. It always seems like something is bending that is not supposed to be bending. Recently, I saw an article on afc-abana on how to make "poz tongs". The bend is done with a U shaped bending fork, and there are instructions to isolate the heat to keep the bends precise. It looks good, but I don't think that these tongs can be made in 20 minutes. Doing a search on "poz tongs" shows the following interesting page: The Best of "Theforge" - Vol. 1 of 3 It give a correction to the fullering orientation. Is the EC valid? It does look that way.