evfreek

Hi easilyconfused and jayco. Thanks for your replies. They are very informative. This blade does cut, but slowly. Good Starrett bimetal blades are so inexpensive, for the amount of cutting that they do, at the hardware store and decent old garage sale "tungsten steel" blades are even more so that it does not pay to economize here. The teeth don't seem to be bent or deformed. It looks like the blade was sheared into several pieces, probably because it was becoming troublesome. Oh well, it was at least worth a try. The scrap cost was minimal, and I did get to try my new "hole drilling" method . There are maybe two or three more things I can do with these blades: 1) knife stock 2) spark test (I tried, and cannot see any nickel, but I am not an expert). Try acid etch too. 3) mini steel rule (just "lost" my 3rd vintage one), bet I won't lose one made from a bandsaw blade.

I made a solar cooker. It could get one hot dog to about 300F. Nice and sizzly. Unfortunately, it took me about as much time to make as my washtub forge. I also had to sounce a special piece of mirror plastic, since aluminum foil wasn't shiny enough. The hot dog would barely get warm. A quick heat transfer calculation showed that the design is marginal because convective cooling around the diffuse focal point is too high. Either the focal point had to be sharpened, or steps had to be taken to cut down the losses. Wrapping the hot dog with foil did not help. Buying special solar foil that was flat black on the outside and shiny on the inside helped a lot. For those of us who think that kaowool, IFB and fireclay is hard to find., that solar stuff is much worse. For larger applications, where convection is not so much of a problem, it might be OK. For example, solar might work well for a glass annealing kiln. About 900 F for a few hours.

A buddy of mine gave me a piece of truck axle. Sparked like 1050. Forged and heat treated (water quench) like 1050 also. I looked at the spark pretty carefully, and it did not look like 4140.

Nothing like a nice big pedestal grinder for cleaning up those tools, but remember that it is dangerous to grind anything heaver than the wheel. The bouncing severely stresses the rock, and these things are fierce when they explode. For dressing big stuff (mushroomed flatter, for instance), the tool of choice is an angle grinder. These wheels are fiberglass laced, and anlthough the dust is unpleasant, wheel breakage is not so scary. It is unlikely that you will get in serious trouble if you: refrain from grinding in notches, discard any dropped wheels, never remove the guards, wear full coverage side shield safety glasses behind a full face shield, use a leather apron and gloves (keep hands away from wheel). I've broken angle grinder wheels before. Scary and hurts (through leather), but I have heard of people dying from exploding pedestal grinder wheels, especially 10" and up. The funny thing was that when I went to a liquidation sale at a fabricator, all the angle grinders (about a dozen) that were on sale had their guards removed and discarded My favorite uses for bench grinders are sharpening drills, touching up chisels (go through a big box when chipping or stone work)., shaping HSS tools, or touching up the bevel on a small homemade knife.

Careful about the zinc. I usually try to avoid burning it off, especially around kids.. I made a Tim Lively style washtub forge. The galvanized sheet metal does not even get hot with all the homemade refractory. The zinc is your friend . This forge is 4 years old and I have left it out in the weather. It is starting to develop some rust spots on the galvy. I don't think that it has many years left in it. That's OK. I have a table forge with a nice Centaur firepot and hand crank blower that can take over. Welds better too. Put enough refractory up, and you don't even need sheet metal. Wood will do.

Hi Jose. Thanks for the reply. I do notice the tungsten getting blunter early on AC. for steel. I just read that AC is often used for brazing with silicon bronze. It is probably a heat into the metal control issue. Perhpas the tungsten is getting blunt because of lack of fine motor control. Time will tell as that skill develops. Just need to practice more. Looking at the charts on the Miller web site, the current capacity of thoriated tungsten is only a little less for AC than it is for DCEN. Much less, though for DCEP. I notice that the heating rate is much more directional with DC. The puddle gets much more slow to establish for angles off 90 degrees.

I went to going out of business sale at a fabrication company. They had some dumpsters filled with different metals and sold stuff out of them for low prices before they were hauled away as scrap. I fished out several pieces (about 3-4 ft long) of 1" bandsaw blade. It felt pretty sharp, and all the teeth were there, so I decided to try out BP0142. Free hacksaw blades. Well, not really free, but close. I have a lot of trouble drilling holes in the ends so I tried a new trick. DCEN on a battery carbon . Zkpped right through, and pretty accurate too. Pretty small HAZ, and nobody uses that part of the blade anyway . The blade was noticably dull. It had a difficult time biting. Not enaough pressure, or maybe it was just plain dull? From the Blueprint, it looked like bandsaw blades wore out by getting teeth stripped off them, and you just had to go to the good sections and they are usable as hacksaw blades. Or, do they wear out uniformly? As for hacksaw blades, I usually break mine before they get dull. But they cut a L O T of steel, including annealed tool steel, before they get retired.

Hi Ice Czar. I built a welder out of a microwave oven. It is not easy. I also saw the plans, but decided on a simpler approach. The painful part is rewinding the transformer. It sounds easy, but it is reall painful . First you need to remove the high voltage secondary. This is absolutely no use for a welder. Fortunately, the secondary is wound on a different section of the transformer. I am not quite sure how I did it, since it was so long ago, but I believe that it involved a hacksaw and a drift. You have to be very careful to make an angled cut so that you don't nick the primary. If you do, the transformer is junk. It is really unpleasant knocking the fine wire out of the core. Once you can get 10-20 percent of it out, the rest will fall out naturally. Then, you have to rewind with thick magnet wire. dansworkshop recommends THHN, but this is really cheesy. THHN is only good to 105 degrees, but even worse, when used in transformer service, it must be derated because the wire is overlapped and under pressure. Use good magnet wire and kapton tape. Magnet wire is expensive. in the thicker sizes. If you use surplus, it will have little holes in it, and you must enamel the transformer with red enamel dope. This enamel should really be vacuum dried, but a vacuum drying chamber is usually not present in a blacksmithing shop. If you don't vacuum it, the transformer will eventually vibrate itself apart from humming and may explode . The core must be disassembled (angle grinder with zip wheel ). Do not attempt to rewind the core without disassembling it and making a decent bobbin. You will nick the insulation and the transformer will be dangerous. Do not knock out the magnetic shunts. These play the same role as the screw in core on a buzzbox. They limit the current to the arc. The reason is that the magnetron in a microwave oven has similar characteristics to an electrical arc: negative resistance. There has to be a means for current limiting. Remember, with the shunts in, the transformer will be "inefficient" in terms of line current. Not all the flux will be available to excite the secondary. Some will leak around the shunt. So, you will need slightly more than one turn per volt on the secondary. Really, you will have to make a test winding to see what the real ratio is. I shot for 30 OCV. This is pretty low, but any higher, and you will have weak current. At 30 OCV, the maximum theoretical current is about 120/30 X 10 or 40A. This is weak. Since it is so weak, it needs to be a DC welder. I bought 4 Schottky diodes surplus at a flea market, and heat sinked them hot into some cutoffs from a salvaged rackmount unit (aluminum plate). At the low OCV and current, this will not even hold an arc with 3/32 6013. It makes a weak carbon arc wihch will barely melt brass. It needs a smoothing choke. This can be made out of a heavy high current transformer. Carefully remove all the wire, and quadruple it up, and rewind it. This is painful, since it does not behave well. Since it will not go in smoothly, you will eat a lot of the core window with air gaps. Again, these air gaps will spell death by vibration from the humming, so it must be heavily varnished with coil dope. Even then, it makes a poor, cold arc, even with 3/32 6013. Probably no better than a Harbor Freight 120V cheap welder. Almost useless for stick welding. But, I held on to this little welder for the time that it would be useful. Remember, there is really no lower limit with TIG. Use the microwave oven capacitor, along with two power resistors for a HV bypass, and bypass all the diodes with film capacitors. Connect it to a HF box for TIG welding. Negative to the torch for DCEN. Turn on 10 cfh of argon. Fire up the HF. It works, and it works well! Just the ticket for fixing boo-boo's and tiny welds. Very smooth and nice arc. Use 1/16 copper coated filler rod. Good luck with the plans.

Hi Jerry. If you are interested in thermite, you may wish to read: http://journalof911studies.com/volume/200704/JLobdillThermiteChemistryWTC.pdf Especially interesting is Figure 3. Disregard all the non-thermodynamic stuff. The appendix is a great reference section for the temperature dependent heat capacities of the reactants. The iron phase transitions are neglected, and these will cause the calculations to be optimistic (pessimistic ). But the error introduced by neglecting radiation and other mechanisms of heat loss is much higher. I wonder that, with sufficient diluent in the form of low carbon steel/iron, you could decrease the temperature requirement of the refractory. The characteristic heat transfer time for small steel punchings or granules is probably on the order of a second, with the high radiative component.

Hi. I just connected a DC welder to my HF box and TIG torch to see the difference. There is not much difference in the quality of the weld. It is more important, it appears, to select correct amperage. The arc is much quieter and smoother. It is also more focussed and predictable. I used DCEN (the standard polarity for TIG). Now I understand why the people in the welding class complained about the sound of AC arcs for welding aluminum.

Once upon a time, I took a metalworking class at adult ed. There were a couple of artists there doing metal sculpture. One of them put her sculpture right in the middle of the shop and she would strike an arc at random times, even when hands-on instruction was given. Eventually, some of us complained to her, and we were sharply reminded to "keep our eyes where they belong". Probably, she was used to being the center of attention and did not give a care about anybody she did not feel like warning. I picked up a trick from an old timer which worked pretty well. Wear a pair of flash goggles. If in doubt, use the lightest shade IR & UV goggles possible. Also, 99% + wrap around polycarbonate sports sunglasses work well. Some people had their doubts, but I chucked a pair on to a Beckman spectrophotometer, and it had excellent near UV protection. A couple of seconds of flash is OK at 50 feet, and 99% will get you in to 5 feet with the same exposure. It absolutely got rid of the "sand in the eyes" problem, but you still saw stars and cursed the self-absorption of the inconsiderate flashers under your breath. Polycarbonate sunglasses are shade 1 or 2, so just add that to your welding glass. For example, if you normally use a 10, you can use the 8 with these glasses and just leave them on all the time. Just watch out for the tripping hazard.

Hey, this should be in the welding section Just kidding. I just bought a cheap used Century stick welder. The construction is more flimsy than the big names, but it works just fine. The cord had the old fashioned "dryer" plug on it, so I needed to make an adapter. This will cost you $20, adding substantially to the price of the welder. From looking around the Internet, there seems to only be one common problem with this welder, besides general cheapness. The magnetic shunt used to limit current does not have a screw in mechanism like on the Miller Thunderbolt. This really feels cheesy, and it jams easily. It really smacks of backyard engineering. Eventually, the magnetic force of the circuit will suck the shunt to the lowest current setting so you will only get a second or so of high current welding out of the thing It's OK if all you do is low amps . Mine is almost there. The fix is to either rebuild the mechanism, drill holes so you can anchor the lever with a pin (then you are stuck with fixed settings wherever you have drilled holes) or cobble up a bracket that you can hold with a vice grip or C-clamp. You may think that paying double for a used Thunderbolt is excessive, but when you snag your apron on that stupid C-clamp, you will think twice. Or, maybe, you will smile knowingly and pat your pocketbook.

Hi fellas. Thanks for the great advice. HWooldridge, I am glad that I can run on AC until I get a DC welder. I tried welding DCEP in welding class once, and the heat really builds up on the tungsten and balls it up pretty quickly. Also, the charts show that max amperage is pretty low for this reason. AC is confusing, though. I ran a couple of beads, and rounded my tungsten pretty good, but I must have accidentally touched it without realizing it. Timekiller, thanks for the tip about Tillman gloves. The kind of glove seems to make a big difference in feeding the filler. I will go to the local welding store to pick up a pair. Don't need much of an excuse to go, since it is owned by a blacksmith and the boys there are great. Hillbillysmith and Dr Dean, you are probably correct about the foot pedal. This welder is a cobbled together stick welder, and does not have a foot pedal. The only thing TIG about it is the torch and flowmeter, as well as the HF box. A foot pedal is not difficult. I have all the parts for one; just need to put it together. They work a lot like those cheap router speed controls, with a special hysterisys and balance circuit for the inductive load. I have a better torch (Weldcraft wp17) but it has no accessories, so it is idle. The beads I made look good, if a bit wobbly. I even burned through once. The interesting thing is that if you burn through, it is much easier to fill the hole than it is with stick. Filling a hole in sheet metal with 6013 almost guarantees me a slag inclusion. When I set the current a little low, the bead rode too high, just like stick. This is fun. I was a little leery about the per foot argon cost, but it is worth the ride. I'm on my second tank now .

Hi. I just bought a welder on craigslist for a very reasonable price. It was not advertised as a TIG welder, but it came with an HF box, a TIG torch, thoriated 1/16" tungstens, and a reg/flowmeter. Unfortunately, it only produces AC. Can this machine be used to weld steel? I looked at the Miller guidelines, and it said that 1/16" thoriated 2% can be used from 60-120 amps on AC, nearly as much as for DCEN. I tried putting down some beads on sheet metal with some filler rod. Looked like decent fusion/penetration, even though I was welding in the wrong direction (away from filler). Now that I read the Miller site, it is clear that a push technique has to be used. The beads had some start-stop craters (no foot pedal and I had a hard time feeding the filler with a gloved hand). Made a funny noise. But it doesn't seem to say much of anywhere on the web that AC can be used on steel. Is there anything obviously wrong with this? :confused:

Hi. I looked into this and it is in a gray area. It is actually very deep and interesting, with some strong voices on both sides. Many construe ripping of copy protected DVD's as a violation of the DMCA, and therefore illegal. This is even if you own the DVD. According to the EFF, this falls under the same situation as reverse engineering. This can make you liable for a violation if you do something as innocent as repairing a welder by replacing a chip whose number was sanded off by the vendor. Since I don't want to create a controversy, I would like to reword my original query. Do the UMBA DVD's have copy protection? If so, I will have to bring my external DVD drive if I would like to watch them on the bus.

Hi. I just came up with an idea to watch UMBA blacksmithing DVD's on my way to work on the bus. But, my laptop does not have a built-in DVD drive. So, I would have to rip the DVD to hard disk before I left on the ride. Somebody recommended a DVD ripper, which I know I need, but they also sell a DVD copy protection remover. They say that this is necessary to remove the copy protection before ripping. I just want to load a temporary image to view during the bus ride. Are the UMBA DVD's copy protected or not? Thanks in advance.:cool:

Hi Hillbillysmith. Your name makes me think of reading Foxfire 5 (fond memories). It's great that you are taking a welding class. I wish they offered that around here. The only courses they have around here have something like 1 hour of instruction and 2 minutes of practice. And, they don't tell you what all the rods are. This is probably because people think of welding as a low pay job and the votech's and community colleges do not offer it. As for an answer to the why not use a higher tensile strength rod, my answer is that it is too expensive for something I don't really need. If I am welding together a bottom tool out of mild steel, a fancy 10018 rod is not what I need. The joint does not need the strength, and in addition, these rods are hard to restrike, especially on AC. Now, if I was welding the functional part on tool steel, the higher strength rod does make a difference. It is easy to see the boost in performance between 7018 and 10018 in use, and even the additional boost going to the correct tool steel rod (like Compax Supreme, or something like that). Aside from this, my main criteria for rod is cheap . Ebay and garage sales can be good. But don't use hi-nickel for high strength applications, or aluminum rod to weld cast iron. Once I bought a large amount of Exergon Tuff-Stuff (10018 basic flux equivalent). I use this to weld almost anything, including mild steel, since it was much less per pound than 6011 or 6013, or 7018 for that matter. I am not into paying $$$ per pound for fancy rod at the welding store.

Hi Ian. Good question. I was puzzling about that one myself. If you look at the straight linear path that the head moves from the up to the down position, the arm pulling the hammer head forms two legs of a triangle with the linear path of the hammer as the base. Therefore, it must change in length as it sweeps out the path, or else the hammer would have to move in a circular arc whose radius was equal to the arm's length. Since it is constrained by the guide, it moves in a straight path. The slight deviation of the paths means that the arm must change length during the stroke. Note that it must only change length if it remained straight. I suspect that it bends slightly, since it appears to be made out of some kind of leaf spring material. I have seen such designs with rollers on the actuating rod joint, but I think that this design takes the slop in the bending of the arm.

Hi AM. I do not like to use tongs with straight untapered handles. Too much work on my "off" hand. But, at the historical farm smithy, some thief made off with all the good (tapered handle) tongs. Just the hard to use tongs with stiff handles remained. So, when I go there to volunteer, I bring a couple of tong rings in my pocket . I make my students taper their tong reins, even if I have to do the striking for them!

Hi RC. I have never tried a website. They work for some folks. Don't work for others. The thing that has worked best for me is word of mouth. No business cards even. My greatest enemy is the false lead. You have got to be able to recognize this. People are cruel in the way that they undervalue you. One of my largest commissions was being installed, and the client joked with me. "How many leads did you get when you were installing it?" He really valued my work. On the contrary, I saw some of the neighbors gawking, and I could just hear them saying to themselves, "He's installing that monstrosity in our neighborhood????!!?" You have to be able to glance at that nosy neighbor, and decide immediately that he is not worth one of your business cards, let alone another glance. And these creeps do you a service by letting you know how crappy they think your work is. What is even worse is the people who undervalue you and show it by not paying or paying slowly. Sometimes they have a big smile on their faces, and a firm handshake. I just remember what the old smith said in Foxfire 5. Let 'em slide twice, but on the third no pay, send them to the other smith. Fortunately, my old company made me do a marketing rotation (ugh) to the district offices. That was an eye opener, and it helped me see through the BS a lot better. So, word of mouth is a double edged sword. I have spent enough time doing lucrative things that are no fun, and you gotta have fun. Remember what Warren Buffet said about how tragic it was for a man with enough money doing something he did not like just for the pay.

Hi. I have "hardened" mild steel. It was a failed forge weld that got burnt. It completely defeated a file (Rc 60+). I later learned from a more experienced smith that burning metal causes it to leaf or string out, with very hard scale between the layers. This composite is very wear resistant but weak. It is useless as a tool. A grinder made quick work of the burnt end. A hot rasp will also work If you want to make emergency tools, I would highly recommend "qualified" rebar. One of my students brought in a piece of new store bought rebar (it was cheaper than the steel from the big box rack). I spark tested it for him right next to a sample of A-36. The difference was striking. It was burstier than truck axle; looked like 1050 or better. It was also red hard, and made that characteristic "clank" noise below a high orange. We made a chisel, tempered one step to bronze, and it was hard. You could tell just by tapping the end. This stuff is cheap! And if it is no good, use it for bottle openers, or hooks or something. Another student made a really nice spring fuller out of rebar. He forgot to qualify it, then he forgot to temper it. It shattered on him. I made one out of "qualified" rebar, and it has fullered a lot of candleholders, letter openers, S-7 tools (careful, keep it hot), etc. Looks just fine.

Hi RainsFire. Good to hear about your positive experience! As you refine the technique, things can only get better. Economical fire control is essential when using charcoal. The sprinkler can is your friend. Fleas can be bothersome. I just got a pretty bad burn from a flea. It shot up under my safety glasses (with side shields) and wedged under the nosepiece. Instinctively, I tried to brush it off with my left hand, but my left hand had a thick leather glove on (a no-no ). I ended up grinding the flea into the bridge of my nose, and it took a long time to heal. Moral of the story: no gloves and no safety glasses around the forge. (If you want to keep the bridge of your nose safer.) Otherwise, if you want to keep your valuable vision and fingers intact, go ahead and put on those gloves and safety glasses. It's your choice. Seriously, though, I have found that fleas are much tamer from homemade charcoal than the typical mesquite or hardwood lump charcoal found at the store. I think that you have better control over the process.

I just found a welder on craigslist for 75 bucks. It said stick welder with an HF unit. I called and asked if it came with a TIG torch and flowmeter. Yes! So I brought it home, and found out that it was an OK deal, but not a great deal. The welder was AC only, and had a 21st Century HF unit sitting on top of it. I had a bottle of argon sitting around in the garage just for such an occasion, and I found out that the torch would not flow any gas. I cut the thumb slider valve, also 21st Century, with a hacksaw, and found out that an internal passage was melted shut for some reason I drilled this out and epoxied the unit back together again. So now the argon has to be shut off with the tank valve. Turned on the HF, and welded a bunch of beads on some 5/64" sheet metal. Works just fine, but the AC is noisy and unpleasant on steel. Low pen is good, though. Is there a good reason, other than pen, that you are supposed to only use DCEN on steel? The HF makes the fluorescent lights flash, and it shuts down the GFI outlet. What a pain. I opened up the unit and noticed that there is no filtering either upstream or downstream. Also, no HF intensity switch. Also, no HV cap! Apparently, the coupling transformer is self resonant. What a pain: very difficult to replace/repair. I will have to try grounding my table and put in a line filter to see if I can calm things down a bit. On the plus side, there was a box of stick rods that came with the machine. Some 6013, 7018 (probably waterlogged), 7014, and NI99 <- . Also 3 chipping hammers and welding masks, and plenty of TIG consumables for the torch. I guess that one gets what one pays for. In retrospect, looking at the TIG torch and the HF box, I have learned something about old American made tools. Not all of them are high quality. You can see where the engineers cut a bunch of corners in the design to save money, compromising the quality, usability and durability. It was not as bad as the Chinese stuff, though. I saw a picture on the WWW of one of those cheap Ebay Chinese TIG welders. I can't remember if it was a Chiry, Riland or CTD. The spark gap was flimsy copper stuck right up against the control board. This is just meant to fail after a short while. At least the 21st Century has the standard tungsten tipped double gap.

Hi Black Ink. It looks like you are kind of like me. You surf the Internet looking for some advice, and then take either the most popular hit or the average of all hits. Sometimes, the average is not the best idea. For example, if someone recommends 6010 and someone else recommends 7018, it may not be the best idea to look for (7018+6010)/2 = 6514. I don't think this rod is commonly stocked. I would pay a lot of attention to what Thomas (my hero) says. First, don't try to reforge an anvil with a cast iron body. Also, don't try to heat the top red hot as a preheat. Thomas is right. For most steels, this would ruin the hardness. There are some hot work steels which can take this treatment, but these alloys are fairly exotic, and are not likely to be found in the top plate of an anvil. I have noticed a lot of people on the Internet saying that anvils have to be preheated to red, else the weld beads will crack off. This advice is somewhat misleading. I can believe that this advice is sincere, if one thinks about the experience that is behind it. But, sometimes you have to think for yourself. First, do you ever see this advice from a "reputable" source? For online information, I like Bohler Uddeholm. They have an outlet in my neighborhood, but their prices are a little steep for me. Think about why this fellow posting on the Internet is getting underbead cracking when he does not preheat to red. Is it because of lack of preheat? Or is it for some other reason that excessive preheating seems to help ? Now it is clear why I don't wish to pay $2 per pound for an anvil which has a lot of damage and weld repairs around the hardy hole. It is just too risky. This kind of anvil is worth $1 per pound, but around here, you can't buy it for that. You cannot even buy half an anvil for that (no heel or no horn).

Bonjour pascalou. That is sure a nice looking anvil, and also a good job on the weld repair. What is "ferritic-austenitic" electrode? This almost sounds like stainless. Might that be a little soft for edges that have to take some impact. I tried some 100018 Tuff-plus impact resistant HSLA rod, and it is definitely softer than the base metal. Is this a good material for affixing mild steel tool handles to sensitive hot work steels?