evfreek

Hi Hollis. Thanks for the very helpful tip. This sounds like exactly what I should do. Time to get out the torch! But it is an oxy-propane, not oxy-acetylene. One of the rivets has not pulled quite tight on the joint, and that is exactly where the looseness is. I have a lot of work to do on my riveting technique, since until now, it has only been for tongs.

You are exactly correct, mcraigl. That is what I should have done. I realized this after I did the deed. It is easy to see how it happened. Before the bars were punched, they were flattened, and were a bit too hot to lay out. Should get a bigger pair of blacksmith calipers. The error was realized after the deed was done. No real harm done, and the experiment was fun and instructive. It was very surprising to me that the amount is so small, since from a volumetric basis, it seems that it should be larger. Is it normal for two bars riveted together to have some wiggle? I am afraid that this will be a vulnerable crack for corrosion in the future (outdoor application). I have not done any of this larger ornamental garden work before.

Hi Mandoro. I just built a side blast forge that was roughly based on the plans from the blueprints. A few things are different. For example, the holes in the tuyere brick were too small. When I tried jamming a pipe in, the brick fell apart. I used a point chisel to try to fix it, but the brick cracked even more. I have successfully used the point on stone and ceramic, but that brick was different. So, I glued all the pieces together with a mixture of kitty litter, fireclay and fencepost concrete. It worked great. Don't worry about using charcoal. It works. Use the real wood charcoal (lump charcoal). I bought a 20 lb. bag for $10 and it only had one briquette in it. All the rest was good. I threw the briquette in my grill. This forge will weld. At least I think it can. I did not try it, but you get the feeling after a while. I did burn the widow's eye on the end of a hook, so that's probably hot enough. One problem, though. Before the job was done, the blower motor started sputtering. Hoping it was the switch or a bad wire, I disassembled it only to discover a short brush. Does anyone know where to get replacement brushes locally? I tried searching on the Internet, and couldn't find a fit. I suppose that one could fiddle with some clay or epoxy to get the dimensions close.

Hi. I think I found out what is going on. It is what I initially suggested :cool: To further bolster the reasoning, I carried out two more experiments with play dough. First, a 5/8 inch disk was punched. This showed the nearly 1/16 inch increase in radius (on all sides). Then, a short 5/8 inch bar was punched. It showed an approximately 1/32 inch growth in length. This is consistent with the increase in spacing of 1/64 inch. Apparently, I do not have a good feeling for even a gross estimate of the results of a simple linear plastic deformation in 3 dimensions. Not to worry, nearly nobody else does. Back to steel, I punched the ornamental piece with a 1/64 inch shrink, and the holes lined up just fine .

Hi Ian. Thanks for the reply. My striker can do that too, but he needs a beer after two such points. Me too. I gotta get one of those hammers.

Hi Chris. I am doing punching O not slitting []. There is a slug. It is less than 1/16" thick. It is very clean and disk shaped and is slightly dished. This accounts for a small amount of the missing material, but very little. If you do the play dough trick all the way to the bottom (can't do with steel ) the results do not change much.

Hi. I was trying to join two pieces of 1/2 inch round with 3/8 inch rivets. First, I punched two holes in the main piece spaced 3 and 3/4 inches apart, then a single hole in the secondary piece. The holes were perfectly centered, but one was a little ragged . I figured that I would mark the last (critical alignment) hole cold, then drift to align. Unfortunately, this reflected poor planning, because it does not account for the growth of the bar when punching :confused: . It does account for thermal expansion, since both measurements are done cold. If the last hole is punched at 3 and 3/4 inch spacing, the final spacing will be larger due to the metal flow from hot punching. Since I was not able to do a test bar, the next best thing is play-dough. I made a bar of the same dimension, and "punched" a hole with a dowel, leaving the slug in the hole. As expected, the metal around the hole swelled out on the sides of the bar, identically to the hot punched steel. But the hole did not move as much as I thought it should. The side swell was about 1/16 inch, and the lateral hole movement was less than 1/32 inch, more like 1/64 inch. Measurements this small are difficult to perform on clay. The next best thing was an area based calculation. The area of a 3/8 inch hole is 0.11 sq in. If the bar is approximated as a 5/8 inch diameter circle and it is assumed that the thickness does not change on punching, the "bar" will grow radially by 0.1102/(pi x 5/8) = 0.056. Thus, the 1/16 inch observation is pretty close for the sides. So, a bar is different than a circle . Where does the extra metal go? Is it somehow restrained by the absence of a free surface (boundary) near the hole? Is it growing into the third dimension (thicker)? This is hard to measure with a ruler, since it does not take much swell to eat up this volume. Anyway, this exercise shows that for two holes, at least, it is probably safe to ignore the slop. Shortening the measurement by 1/64 or less seems safe. This amount of slop is pretty straightforward to drift out anyway, and a hot rivet will fill it easily. It does make one curious, though.

Hi Ian. Nice hammers. How hard does the little helve hit? As hard as a striker? ;)

I have found that dimmer switches do not work well on shaded pole induction motors. The reason is that they are an inductive load, and the dimmer contains a triac which does not have good control over that type of load. A cheap dimmer is considerably improved for bathroom fan duty if it is strapped with a series resistor and capacitor (about 10 ohms and 0.01 microfarad for starters). Since induction motors do not respond well to phase control, but rather to things like VFD's, it may be simpler to use a sheet metal air gate. Or even simpler, a Y1K gap in the feed hose.

Hi. My spark testing guru tells me that they spark as simple high carbon steel, about 1070. Standard cautions apply on cutting or welding. Careless welds can crack. Can be hard to drill without annealing. I have never tried using them, but have heard that they make a good quickie hot cut.

I use a free plastic container. Don't try this with any flammable oil I use a non-flammable aqueous polymer quenchant with oil-like quenching speed.

Hi. To follow up with some of the information I was seeking, it does not seem possible to rent a TIG welder around here. The local companies only have stick and MIG welders available. I guess that there is pretty low demand for rental TIG welders, and there is still a high chance of goofing one up. Thanks for the advice to buy a Miller, if choosing an inverter. I got burned by a dead one from Craigslist. The seller swore it worked, but he couldn't show me since it had the wrong plug Boy did his face fall when I whipped an adapter out of my satchel He was so upset when I showed that it would not strike an arc, and he whimpered that "maybe I could repair it, since I had driven so far already." NOT!

Hi Glenn. I am looking for low end and portable, like a maxstar, which would be useful for silicon bronze or small mild steel work. Optionally, I would like to try aluminum, but this is second priority. johnny99, thanks for the reply. My stick welder is not DC. But I did buy some diodes, an air cooled torch, a small tank of argon with a flow meter, and a hose. Still need a few more things to cobble it together (heatsink, plugs, leads, gas lens, tungstens, etc). Figured I would do the craigslist or Ebay rental thing, but found out that it was either risky (inverter) or heavy (transformer). I was unclear about dipping the tungsten. If you flinched and dipped the tungsten, the instructor yelled "next" and that was your last chance for TIG during the class for the semester. I am not blaming the instructor; it was an equipment, student number and time crunch. But, on the first weld, it is easy to make that mistake. With one successful weld under my belt, I would hardly consider myself a TIG weldor.

Hi. It looks like I am never going to buy a TIG welder. Used prices are too high, and I don't want to buy an electronic one after getting burned once. Normally, one would rent one if the usage time can be scheduled accordingly. Has anyone tried renting for that occasional installation job? How much does it usually cost for a small inverter welder with a tank? I saw someone post $35 per day before, but I don't see anything that low. The big used non-squarewave machines sell used here for about $1000. These are very heavy and therefore not really portable. The competition is the Techshop, which costs $100/month for membership, plus the cost of gas, and a couple hour TIG class. I took a metalshop class which was supposed to teach TIG welding, but due to others' demand for the machine, not everybody got to try. One dip of the tungsten, and you were done for the year. That's not the way to learn, but a 1 hour familiarization and being turned loose on a machine is probably not either. A stick welder is just so useful and cheap that there is just no excuse for not buying one, but a TIG, especially around here, is another matter :(

My minimum setup when I first started was a lump of homemade refractory from garden clay, a concrete block, a ball pien hammer, vice grips, and a propane torch held between my legs. Believe it or not, this worked for making custom bike tools. Now, I do not cycle, but I still do blacksmithing. And, I have replaced all these tools, sometimes with more than one iteration. Anyway, Thomas Powers (my hero) once said that it was the more serious beginners who held on to his loaner anvil for the least time. ;)

Hi Glenn. Experimenting with using wood to forge is very interesting. Once upon a time someone posted on his experiences with wood pellets. He was able to get a pretty good heat. There is some kind of rule I heard of like 6-10X the fuel size for the firepot depth. That is why it is so hard to get a hot fire with big pieces of wood. The fire behaves like a shallow fire. Cold and oxidizing. Actually, it is a little more complicated than that, and the scaling is non-linear in the good direction. In other words, the rule may become more relaxed with larger size fuel. I saw a wood fired forge in action that could get up to a sparking heat with scrap wood (like pallets and construction scrap). It had a firepot that was about 3 feet deep. Hmmmmmmmmm, this is about 6-10X. This may help to guide the direction of your experimentation.

Hi Irnsrgn. Thank you for sharing your experience with us. The voice of experience is always helpful, because it tells us details which no amount of theorizing can fortell. I have a question. A while back, I tried the 1" ball bearing test on a bunch of anvils. The interesting one was on two anvils in an old historical smithy. One anvil had 90% rebound, and the other had 70%. On closer examination, there were telltale ground down weld beads on the one with 70%. Checking more carefully showed higher (80%) rebound on the unwelded parts of the face. Have you noticed any differences in rebound (or any customers)? I realize that you can't move very much metal by just bouncing a ball bearing around, but it is an interesting test.

Hi Valentin. It looks like you have put a lot of time and energy into this. Instead of getting discouraged, try "thinking out of the box". Thomas has a very good suggestion. Try a blown burner. This is what I wanted to do after a few failures with naturally aspirated burners. But, I never found the right (cheap enough) blower until I stumbled into one at a garage sale. At this time, I never heard of dryer or dishwasher blowers. I tried out one of the designs on the WWW, the Oliver Backwind Burner. Failed, and I posted a question on a blacksmith's group. I received a reply that nobody uses that design because it is unreliable. Later found out that I had propane delivery problems. I ended up getting pushed, because one of my friends enrolled me in a crafts fair at the last minute and I had to get busy. I used the design at Anvilfire. It worked OK, but only for forging. I was able to make enough items to fill my table. Later, I talked with the instructor in one of the forge building workshops. He said I used too large of a MIG tip, and the forge was running rich. That's why it would not weld. So, I took his advice, and the forge welded. I made sure to look him up and give him the rest of the package of useless (to me) MIG tips. Good advice is worth more than stuff. I tried 3 times to get it right, and this is too much. 6 times is really too much. If you really want to succeed, buy a burner from a reputable source (Larry Zoeller, Chileforge, or people tell me that T-Rex is good). Then, take your time and reverse engineer it :cool:. If you want, you can make an exact duplicate (backup) and convince yourself that you can succeed. If you still cannot succeed, have somebody go through it with you step by step. Take notes, and see if you can reproduce it after he is gone. Don't worry, I know people who cannot duplicate it 15 minutes after the expert leaves the room. That doesn't mean you are dumb or inadequate. That just means that burner building is not your thing, and you should move on to something else, like, errrr..., forging . Anyway, I get more out of using burners than building them, and although I am proud to show off the little forge at conferences, it is more interesting banging stuff out.

Hi Joseff. It looks like olive oil would be a pretty good quenchant, except for the price. There was an article yesterday in the food section of the paper in the Food 101 section by Robert Wolke, professor emeritus of chemistry from the University of Pittsburgh. It talked about the smoke point of food oils, saying this is the point at which the oils degrade and release toxic chemicals. Olive oil, as long as it is the clear extra refined stuff (light) is pretty good. But not the deep colored extra virgin oilve oil. Here are the numbers: canola 400F, cott 420, sunflower 440, corn 450, peanut 450, extra light olive 468, saf 510. I am not quite sure of these numbers since my notes were scrawled down, but the point of the article was that olive oil was OK for deep frying if you use the light. He went on to say that oils which have been taken up to their smoke point are not really edible and should be discarded. Hi Tek. The baby waste product is not really all that bad. At 2% or so by weight, it is not even offensive. Also, it is safe to dump this on your lawn. Our county has laws against grey water (bath water containing skin particles). This cannot be dumped on the lawn due to the risk of generating airborne disease containing particles. Olive oil is also safe to dump on your lawn, since it is biodegradable, and the bugs will eat it up fast. If you don't like baby waste product, you can bypass the baby. Mega packs of diapers from Costco cost about 20 cents per piece. A single diaper should be enough to make about 10 liters of quenchant. If you buy small packs at the local grocery, they are about 50 cents each. I am cheap and go to the local baby. These are free. Do not select the ones with solid waste product. Not only are they very offensive, they are actually dangerous, from a pathogenic standpoint.

Hi Christopher. You really need some real charcoal. There are no restaurant supply houses around who have it? Some of my buddies in Texas had a way to make charcoal. Fire up a BBQ grill with lots of wood. Cook something which takes a lot of cookin' like pot roast or brisket. When the wood is good and charred up, run it through a "Texas sieve" (a torched out brake drum with rebar grille welded in). Encourage the charcoal to fall through by striking the wood with a piece of rebar. Put the hot lumps in an airtight metal container like a cast iron dutch oven. Forging over wood is tricky. You really want to get some good coal or charcoal. I have seen people do it. You need a very deep fire with wood. Something like 12 inches. I have never done it. But, I have done something like it. When running low on charcoal, I use charcoal below the steel, and wood above it. The wood acts like the insulation. Bits of charcoal periodically fall into the fire, replentishing the charcoal already in the firepot. Help them along occasionally with a poker. A layer of fuel is required above the steel, but it does not have to be charcoal. The layer below should be, though.

Hi HW. Thanks for the quick reply. The brass shim fix sounds great to me. I'll give it a try.

Hi. Someone left behind (donated) a 25 pound Little Giant power hammer and left the country. Everything on it looks good, except for some slop in the ram guide. It has 0.0125 in front and 0.0075 in back, on each side, according to feeler gauges. The rattling can be felt if the hammer head is given a shake. Is this too much (requiring relining)? There are no more shims left on the ram guide bolts, so this is it on that adjustment. Or can the hammer be operated without risk of galling? The only thing that I saw using a web search is that "all gap should be adjusted out". :confused:

I noticed these number punches on Ebay item 250118483331 Does anybody know how they were made? It says in the description that they are "Blacksmith-made". They look a little too shapely (for example the number 2) to have been made with matrix punches. The interior features look too smooth for grinding or engraving with a Dremel or engraving cutter.

Hi Kogatana. Mild steel can have hardenable spots. I was in a blacksmith workshop making spatulas. They used A36 (kind of like mild steel). I found that if you quenched from red before drilling, some holes could not be drilled. The instructor said that this kind of steel can have hard spots. But, you said above: "hard without me tempering it?" I think this means hard without quenching????? In that case, maybe the burned end is very hard due to carburization in the fire. I missed a weld, and it just would not stick for the second try. The face of the scarf was silvery, and it definitely was NOT scale. After letting the piece cool, it was too hard to clean off with a file. It required an angle grinder (and a MIG welder). This stuff was good and hard, and no quench. When you did the spark test, did the spark test look like high carbon steel? Steel with 1%+ carbon has a very memorable bushy appearance.

Hi Bruce. Thanks for that tip on the light sheen. It worked. I gave the oil,water quench a try with about a 1/16" layer of oil. No fire, but stench and mess. The scale did not blast off leaving a silvery finish as it did for the plain water quench. The steel was harder than with the diaper quench, but slightly softer than plain water. A file would scratch but not cut. So still pretty hard. Quenching time was comparable to the diaper quench. Lecithin might work. It is more of a surfactant and viscosity modifier than a builder. It may be good in combination with food starches to help them blend with water. But, I am staying away from these because of the prep requirement (starches don't really thicken unless they are cooked) and the microbial degradation, which can also lead to stench. I just found a reference by Houghton on sodium polyacrylate quenchants. Less film formation during the vapor blanket phase, and more convection suppression during the convective phase. Exactly what is needed for crack sensitive steels. They don't seem to sell small quantities of the polyacrylate to backyard blacksmiths. So, back to the diapers. One polymer that is very visibly absent from the literature is the polysulfonates such as ammonium laureth sulfate. These are very inexpensive. Cheap shampoo can be had for $1 per bottle at the dollar store. These concoctions have very high viscosity, but the problem is uncontrollable foaming . Foam suppression is possible with ionic salts and small amounts of oil to form an emulsion. This could be a more friendly version of Bruce's oil quench. Animal/vegetable fats + laureth sulfate + salt may make an interesting biodegradable combination polymer oil quenchant with similar performance. Bob, the reason why the brine is a more rapid quench is that the salt crystals that form with boiling destabilize the vapor film by producing nucleation sites. If you try it in a glass bottle while looking closely, you will see exactly what they are talking about.