|WELCOME to the anvilfire Guru's Den - V. 3.0|
THIS is a forum for questions and answers about blacksmithing and general metalworking. Ask the Guru any reasonable question and he or one of his helpers will answer your question, find someone that can, OR research the question for you.
This is an archive of posts from Octobet 18 - 24, 2001 on the Guru's Den
This is the link to our new auction test site. The anvilfire Tool Auction is another Andrew Hooper Production
Not long ago I posted a question about having a 200 pound chunk of steel turned into an anvil. A friend of mine who is taking a welding course at the local tech school is willing to take this on as a class project. She's asked me if I want a hardened steel plate welded to the face of this chunk.
|Khym - Thursday, 10/18/01 00:27:34 GMT|
Anvil Face Khym, a plate welded around the edges does not perform very well but it is better than nothing. Anvils with a hard face plate were forge welded together and the plate has a continous weld between it and the body of the anvil. Folks making anvils from plate often hard-face the surface with hard facing rod. This takes LOTS of hours of welding and grinding.
|- guru - Thursday, 10/18/01 01:28:53 GMT|
Okay, I am going to put my Buffalo Forge aside for the time being and work on another project. It is a "Silver" post drill, made by the Silver Mfg Co, in Salem, Ohio. Now , can you help me with information, pictures, anything? I will be ever so appreciative. Thanks again, George
|George - Thursday, 10/18/01 01:52:42 GMT|
Hard Facing. A few years back, a Turley "grad" hard faced his old anvil, and the facing got multitudinous cracks when he used the anvil. Too hard; too brittle.
|Frank Turley - Thursday, 10/18/01 07:47:34 GMT|
Douglas; where along the Hudson Bay are you located?
Welding a plate on the face: if they want to weld from the center out---heavy V lots of passes should work a treat. If you want to hardface watch your alloy! You want a tough workhardening alloy not a *HARD* brittle one. Ernie Leimkuhler's webpage on how to make an anvil from scratch goes into some suggested ones IIRC.
GOt the first load for the MOB hammerin in the truck out in the parking lot at work---waiting for security to "stop by and howdy".
|Thomas Powers - Thursday, 10/18/01 13:16:24 GMT|
Anvil Faces, Yes, I generaly don't recommend hard facing or using hard facing rod for repairs. It is designed primarily for abrasion resistance. However, many do it. Flame hardening the surface of a medium carbon steel (50 - 75 pts) block is much better if making a DIY anvil.
On repairs I generaly recommend DON'T DO IT. Work around the faults unless the anvil is useless.
Silver Brand George, Sorry, never heard of them. However, there is a good chance it is a copy of a Buffalo or a Champion. We have a few pictures posted on our 21st Century Page. The problem is that these came in hundreds of styles. Some had fixed gearing, some changable gearing, others had back gears and seperate feed gears while the simplest had a cam that operated a ratchet and paw. Allmost all had flywheels. Later flywheels (after electric motors) had square sections to run a belt on while older ones had a round section. Some had pullies for running on line shafting. This usualy included a floating pully to clutch the machine in and out.
Almost all these machines were no longer made much after the 1930's or 40's and there have been no parts for over 50 years. Even the 1/2" shank "blacksmith" bits are no longer made.
|- guru - Thursday, 10/18/01 13:24:01 GMT|
Will a standard propane torch produce enough heat for riveting? I have tried to heat rievts with mine, but had little luck. Would a Mapp or Mapp Oxy torch work better, or do I need to move all the way to up Oxy Acetlane?
|- Jim Freely - Thursday, 10/18/01 16:02:13 GMT|
Andy, good idea on the venturi. Most standard blowoff guns have such a venturi arrangement. I should have thought of that when I used the air. But then, I was only using the air temporarily. Even with a venturi, it would still be an inefficient solution. Not that everything has to be efficient, grin. Entropy be dammmed. Bigger grin.
|- Tony - Thursday, 10/18/01 16:58:14 GMT|
Riveting Jim, it depends on the type of rivet and size. I cold head small rivets 3/16" - 1/4" (~5 - 6mm). Especialy if I can back up the rivet on the anvil. For hot heading a propane torch is difficult to use but if you can handle the rivets loose a micro-forge or bean-can forge powered by the same torch will do the job. Otherwise a small MAAP torch would be required for the job up to about 1/2". Over that you need a larger torch or use the forge.
If you are heading rivets in a frame then it is important to find some way to back up the rivet. Support the head on a corner of the anvil or with a heavy hammer or sledge. If it is in a tight spot a long bar (say 1" round/square) will provide good directional mass. It helps to form a heading deppression in the end to help keep it centered on the work.
|- guru - Thursday, 10/18/01 17:08:27 GMT|
HEY, THANKS FOR SUCH A QUICK ANSWER ON THE SILVER POST DRILL. COULD YOU NOW DIRECT ME TO THE 21ST CENTURY PAGE. HOW DO I FIND IT? YOU GUYS ARE GREAT. THANKS, GEORGE FROM MICHIGAN
|George - Thursday, 10/18/01 18:02:10 GMT|
George, see the menu at the upper right? All our pages are accessable there as well as our advertisers and related pages.
OBTW - ALLcaps is considered yelling on the web.
|- guru - Thursday, 10/18/01 19:18:59 GMT|
Cold Heading Rivets:
Is this what it sounds like, just peening the rivets with no heat at all? I've never tried it.... Are there any trick, or just use standard riveting techniques?
Thanks for the help!
|- Jim Freely - Thursday, 10/18/01 19:29:54 GMT|
Jim, Yep. one heavy blow upsets the rivet. Lighter blows spread and shape the head. I often use my 3.5# cross pien for the first blow and then a ball pien to finish if not the heavier cross pien.
|- guru - Thursday, 10/18/01 19:57:13 GMT|
I am a student in the 8th grade at Hanford Middle School Wa And I have A project to make a sword or dagger. I would Apperiate Any help of info you could offer. Thanks
|Nate Martin - Thursday, 10/18/01 20:07:31 GMT|
STORMCROW, I finally got around to straightening a railroad clip. I made a big ol' cold chisel that came out 5/8" x 1 1/8" x 7". I hardened in water at a medium cherry red and tempered to a peacock (mottled blue and purple). It holds up to cutting mild steel. It has some kind of lot number on it: B 00 132RE. I suspect from sparking it, that it is either at the low end of the high carbon range, or that it is a silicon manganese spring steel.
|Frank Turley - Thursday, 10/18/01 21:29:22 GMT|
NATE, I recommend you consider making either the dagger or sword out of hardwood such a maple and then painting the pieces. The parts, blade, guard, grip and pommel can be made seperately and shaped to fit as would metal parts. Professionals often model fancy new blade designs such as those used in movies (Rambo, Conan. . .) in wood first to see how they will look. It is a good start as many of the details are the same.
Swords are a difficult project for even an experianced metal worker. A dagger has the same pieces and is much easier to make. I generaly suggest to the would-be sword maker to make a really fine knife first. If that is too difficult a project then you haven't wasted you time and money on the larger project. There are several methods used by knife makers. Forging is obvious but probably requires tools that you do not have access. "Stock removal" is very common and is also part of making many forged blades. In this process the blade is shaped by sawing and grinding to shape from a flat bar of steel. The guard grip and pommel are made by the usual methods which can include carving from solid brass, casting, forging, or a combination of methods.
In the stock removal process you will need to have access to a heavy duty grinder. Belt grinders are most commonly used but other types can also be used. Be sure to wear safety glasses when doing all grinding.
The easiest way to start is making the blade from an 8" flat file. If you are careful and do not overheat the steel while grinding the blade will not need to be hardened. The tang can be used as-is. The first step is to mark the shape of the blade and cut the profile. For a double edged dagger the profile will be symetrical and curve to a point. In this case the profile will be ground instead of sawed because the steel is too hard to saw.
After the profile is finished then grind off the file teeth and start to grind the blade taper. The cross section of the blade should be diamond shaped with a ridge down the center. Grind the sides until the edges are about 1/16" to 1/32" wide then grind the edge bevel. Repeatedly cool the blade in water as it gets hot. If the metal discolors (turns blue) then you have overheated it. As the edges get thinner it will be easier to overheat so you will need to quench more often and use less pressure while grinding.
Grind about 1/2" of the end of the tang round (cylindrical). Carefully measure it and use a die the thread the rounded end. You may have to grind to the nearest even size. A little undersize (.005 -.010") will thread much easier. The thread will hold the pommel.
Use a fine grit to finish the surfaces of the blade. When done it will need to be tempered. Files are VERY hard and brittle and will break easily. Tempering reduces the hardness a little and the brittleness a lot. To temper the blade preheat a cooking oven to 500 degrees and then place the blade in the oven. Let it soak about 1/2 hour and then shut off the oven and let the blade cool in the oven.
The guard and pommel can be made of either soft steel, brass or aluminium. A rectangular hole is cut by drilling several holes and then filing to shape. The guard will need radiuses filed to fit the radius of the original file tang. This is the correct shape to prevent the tang from breaking off. The fit needs to be snug. Shape the guard as you wish by grinding, filing and polishing.
The pommel is made of a larger block of metal. It is drilled and taped to fit the thread on the tang. The shape can be turned on a lathe or shaped by whatever process suit your design.
The parts are then assembled and the size of the grip measured. The grip is then drilled to fit the tang and shaped to fit. It should be just long enough that the pommel can be tightened against it. After testing the assembly and finish fitting and finishing the parts everything is taken apart and cleaned. Then two part epoxy glue is used to hold the guard, grip and pommel in place for final assembly. Some glue on the threads will make sure the pommel does not work loose. The epoxy also fills the space around the square tang going through the round hole in the grip.
A professional knife maker would silver solder the guard to the blade first. This makes a tight strong assembly. However, is requires an oxy-acetylene torch and much practice. Then assembly would proceed as above.
Making a forged blade requires all the same steps except for the profiling and heavy grinding. However, it still requires much grinding and also complete heat treatment of the blade. A wooden model can be made using the same grinders but can also be shaped largely with knives, scrapers and hand sanding.
One option for a "wall hanger" dagger or sword is to make the blade of aluminium. A hard aircraft alloy such as 6061-T6 or 7057-T6 is best. The blade is made by nearly the same methods as above. Profiling is done on a band saw (slow metal cutting speed required). Shaping can be done using a belt sander but aluminium tends to clog the belt. Never grind aluminium on a wheel. Most of the shaping should be done using files. Start with a special coarse cut aluminum file or rasp and then change to a 10" flat bastard cut file before finishing with sand paper. Aluminium can be buffed and polished to look like silver and will retain the finish a long time. It is also light weight and easier to work than hard steel. It is a step above making a wooden blade but will look like the real thing.
We sell tool steel as well as aluminium and brass in our on-line metals store. There is an iForge article on scrapers and several on polishing on our 21 Century page. There is also a heat treating FAQ on that page.
Many books have been written about knife making and your public library should have several. Even if you choose to make it ove wood these will have details you may need.
|- guru - Thursday, 10/18/01 23:01:01 GMT|
Thanks, Frank. I'll probably try to make a handled hot cutter out of one, amongst other things. I believe that maybe I saw someone claim they were 1080, but I'm not sure if that was it or not.
|- Stormcrow - Friday, 10/19/01 01:27:23 GMT|
I don't know if you can help, but it's worth a shot.
THIS IS ONE OF THE RAREST AND MOST UNUSUAL METAL ALLOYS, THAT IS COMPOSED OF 5 ELEMENTS WHICH INDIVIDUALLY ARE SOLID AT ROOM TEMPERATURES. THOUGH IT DOES NOT CONTAIN MERCURY OR GALLIUM, IT MELTS AT 117̊̊F OR 47̊̊C. IT LIQUIFIES QUICKLY AT TEMPERATURES OF 125̊̊F+ - WHICH MEANS IT MELTS IN YOUR SINK UNDER HOT TAP WATER !!! LEAD AND CADMIUM, ALONG WITH INDIUM, BISMUTH AND TIN, WHICH REQUIRE REGULATED DISPOSAL AS PER THE EPA –– NOT THAT YOU WOULD WANT TO THROW THIS VALUABLE STUFF AWAY !!! YOU SHOULD USE COMMON SENSE IN ITS HANDLING, BUT YOU WILL NOT FIND THIS EASILY ANYWHERE ELSE. FIRST DISCOVERED IN 1938 BY DR. SIDNEY J. FRENCH, FROM WHICH IT GOT IT’’S NAME, FRENCH’’S METAL IS A TRUE SCIENTIFIC ANOMALY AND CURIOSITY, SINCE ITS 5 INGREDIENTS, INDIUM (A RARE ELEMENT), BISMUTH, CADMIUM, TIN AND LEAD ALL MELT AT MUCH HIGHER TEMPERATURES BY THEMSELVES. SCIENTISTS, CHEMISTS AND METALLURGISTS CALL THIS A: ‘‘EUTECTIC METAL’’, BUT ‘‘LIQUID METAL’’ OR MAYBE ‘‘ROSWELL –– AREA 51 METAL’’ IS MORE APPROPRIATE. WHY DOES IT GO LIQUID SO EASILY?
I would be grateful for any help you can give me in finding a source for this.
|M. Hostetler - Friday, 10/19/01 03:44:03 GMT|
M. Hostetler, We'll probably need to defer to the head honcho guru on this one, but I reached for a few reference books which are about one yard away in my personal library. First, I assume that you left out a decimal point on your temperature readings. 12500 should be 125.00, verdad? My references refer to "low melting alloys" of bismuth, cadmium, and lead. *1* Tin is also included in another book, but not indium. These are also called "fusible alloys", and "the general rule is that an alloy of two metals has a melting point lower than that of either metal alone. By adding still other low-fusing metals to the alloy a metal can be obtained with almost any desired low melting point." Wood's alloy was patented in 1860 and was used for automatic sprinkler plugs. Other alloys by name are mentioned in Materials Handbook, but not "French's". *2* Various combinations with melting points are listed in my 20th edition of Machinery's Handbook, page 2270.
*1* VanNostrand's Scientific Encyclopedia, Fifth Edition.
*2* Materials Handbook, by Brady and Clauser, 1977
|Frank Turley - Friday, 10/19/01 11:27:19 GMT|
Low melting metals: there is a brand called "cerrobend" IIRC that is sold to use for bending small tubes that melts in boiling water. Do a web search on that.
As for making a knife from a file: may I suggest you draw temper on it *first* to make it much less likely to break during the working on it---anybody ever *drop* the blade they were working on? Especially when just starting out...
Thomas off to the MOB hammer-in in 2 hours!
|Thomas Powers - Friday, 10/19/01 13:26:39 GMT|
Nate, Considering the no tolerance policies in pretty much EVERY school in this country, I would advise NOT bringing any knife to school nowadays. The consequences are usually expulsion. They will probably treat a wooden blade the same way as a metal one. If you're doing this for yourself, definitely follow the good Guru's instructions! I worked on a couple of blades, wooden and metal, when I was your age & learned a lot. Good luck!
|Mike Roth - Friday, 10/19/01 14:20:52 GMT|
I am a Sophomore from Ilwaco Highschool in Ilwaco, Washington. My Seinor project will be an attempt to forge a sword. To prepare for this, I am going to have our shop class build a forge. However, I have not been able to find blueprints for a forge anywhere. Could you help me out?
|Cory Bardonski - Friday, 10/19/01 15:20:45 GMT|
Cory, Please read my post to Nate, above yours. Also, Swordsmithing/bladesmithing is one of the most advanced forms of blacksmithing & shouldn't really be done by a beginner. I would suggest looking throught the i-forge demos for a project if you want to use blacksmithing for your project. I believe there are forge plans on the 21st century page. Good luck! Blacksmithing is a very rewarding hobby!
|Mike Roth - Friday, 10/19/01 15:44:15 GMT|
Low temperature melting alloys: Cerrocast, Cerrobend, Cerromet Years before I mispelled the product name as Ceracast or Ceramet instead of Cerrocast.
These are the only folks that I know make it. From Thomas Register:
Cerro Metal Products Co., Alloy Dept.
P.O. Box 388
Bellefonte, PA 16823
Low Melting, Fusible, Non Shrinking, For Tube Bending, Work Holding, Pattern Making, Die Mounting, Medical Shielding
Devices, Mold Making, Forming Dies For Sheet Metal Parts, Proof Casting.
In the past these folks made alloys that would melt at body temperature. A common use is making unusual shaped cores in plastic or ceramic pieces.
There are also non-shinking and expanding alloys used to bed in parts such as ways in machine tools. The ways are precision alligned and then the alloy poured around end of the ways in a pocket (usualy in a casting) to lock it in place. I've used both types of alloys (low temp and expanding).
Why? Metalurgical Science? Now that is a good question. I suspect the metalurgical reasons are not known. There is no predictive science of metalurgy like there is in chemistry. It is all trial and error. Within certain limits set by trial and error you can make minor predictions within a certain narrow range but they must still be proved empirically.
So called "memory metal" that returns to its original shape with the application of a small amount of heat was discovered accidentaly by researchers studying bronzes. We don't know why it works, only that it works. All alloys are the result of thousands of years of experimentation.
IF we were to develop a predictive science in metalurgy then many things that are science fiction would become science fact. Super conductors, themal conductors, light weight radiation shielding making "personal" atomic reactors possible, lighter more efficient engines and devices of every type. . . Things that would make unbelievable advances in technology.
The problem is the number of variables. There are some 30 odd metals used in common alloying and then some non-metalic elements that are either added to alloys or are impurities that have known effects on alloys. Then there are the properties (also variables) that result from the infinite number of possible combinations of metals.
density (almost predictable but not quite)
strength at various temperatures (high, low)
hardenability or heat treatability
subseptability to fatigue
radiation density (or transparency)
color, visible light reflectance
magnetic density, effects
Recently metalurgists completed what is known as the "Binary Alloy Series". It is a compilation of data on every possible combination of two metals in as many proportions as possible. It was organized empirical research. That is hundreds of thousands of alloys. It was hoped that this would help lead to a predictive metalurgy. However, we commonly use alloys with 3, 4 or 5 metals. It could take thousands of reasearchers hundreds of years to test most of the possibilities.
And, to make things more complicated, today we combine metals by powdered metal techniques that were previously impossible by melting. Using this technique more non-metals are added to the possibilities. Ceramics are now used in semi-conductors and super-conductors. . .
Perhaps some new Einstien will come along that can balance the hundreds of variables in his brain and SEE relationships that produce a predictive metalurgy. However, it is more likely that basic scientific research will turn up the answer. But when we shut down basic research like the Texas Super Collider, or the materials research for sub-ordital passanger aircraft, then we reduce the possiblity that science will produce an answer to this question.
Today we use quantum theory in computers that we use every day. It is still a mysterious bit of science that we do not yet fully understand yet we apply it to everyday items. 30 years ago it was nothing more than an oditity of sub-atomic science with no foreseeable practical use. Fractals were a quirky bit of pure mathematics that seemed to have no practical application a few years ago. Today they are used in image enhancement and compression algorithms found in computers and digital cameras. "Fuzzy Logic" was another of those odities that quickly became a joke of polititions yet is quietly finding its way into everyday devices that need to make a best "guess" such as in weather prediction or a smart thermostat that predicts what your furnace will need to do tomarrow based on yesterdays weather. . .
It is easy to attack the absurdities of pure research, yet today we take great advantage from what was laughed at 20 or 30 years ago. We NEED research projects like the super collider.
|- guru - Friday, 10/19/01 15:57:41 GMT|
MISSING POSTS: Sorry Folks, we had a server error (out of disk space) and lost a bunch of posts. I've updated from the last downloaded log. However, my long answers about Machine Shop references was lost.
|- guru - Saturday, 10/20/01 14:29:11 GMT|
Jock, I reread your discussion about lathing tennons. I think that you said to start the cutter on the end. I tried starting on the side and it stalled the lathe. Could you just go over that point one more time.
|- l.sundstrom - Saturday, 10/20/01 15:13:02 GMT|
Machine Shop References: This is a repeat post due to yesterdays lost posts. . It is probably not as good as the two original posts. Sorry, even the question was lost.
All the following books were found on BookFinder.com. I have stopped recommending the used book sources gobbled up by Amazon.com who has either ruined them OR because of who they are, many small book dealers have dropped out.
Metalwork Technology and Practice Published by McGraw-Hill and previously by McKnight. This is a general metalworking text used in many trade schools. It covers all the basics and I highly recommend it to ALL new metalworkers no matter what the field.
Machine Tool Practices Published by John Wiley and Sons is another book used in trade schools. This is a much more detailed reference covering all types of machine tools and how they are used.
MACHINERY'S HANDBOOK The classic reference by Industrial Press. See our review. This is not a how-to but is a necessary reference in every machinist's tool chest.
The three books above retail over $100 each new but are considerably cheaper used.
American Machinists Handbook By the authors and publishers of MACHINERY'S HANDBOOK. This is more of a hands on reference for machinists. It does not contain the in depth technical charts of MACHINERY'S.
How to Run a Lathe by Southbend Lathe Co. This is a classic beginners reference to the lathe and everyone should start here with the basics. Do not let the drawings of the old flat belt lathes put you off. The controls and tooling for the standard engine lathe has not changed in over 100 years.
Starrett and Brown and Sharpe publish catalogs of their precision tools that also include how to read them. These are free from machine shop and industrial hardware suppliers.
Manuals, IF the makers of your used machinery still exist then see if you can get parts/operations manuals for them. These generaly do not have much how-to but may cover adjustments and attachments that were available. Often used lathes do not come with the indespensible steady rest and these can sometimes be purchased to fit 50 year old machines.
There are also many OLD machine references (from the 1930's) that cover machining methods and setups.
Beyond the basics, machine setups and furniture use on tables and face plates is something of an art. Many machinists learn the tricks of the trade from working with others. However, every job poses new chalanges and often it takes imagination to come up with good setup solutions. Some of us have it, others do not. Many tooling solutions are available with standard tooling while special tooling or jigs is often the only solution. Generaly if you are going to do a job more than once a simple jig or tooling block can pay for itself. The value of a more complicated jig must be balanced against the number of times it will be used.
|- guru - Saturday, 10/20/01 15:30:34 GMT|
NEW Tools: There are a few precision tools that should be purchased NEW by every machinist (amature or professional). These are very common used by are almost always worn out. So buy these new and from a quality maker.
0-1" Micrometers. These are the most often used. Digitals (non-electronic) can prevent a lot of mistakes. I prefer the ones made by J.T. Slocomb Co., Glastonbury, CT USA.
0-6" Dial Calipers. Thise are probably the most generaly useful measuring tool made. I like my Fowler Hellios brand but the Brown and Sharpe's with a covered rack are very good. Open racks can be easily jambed by a simple piece of grit and take all day to remove. . . Do not buy cheap calipers, they are not worth it.
0-1" by .001" Dial Indicator with Magnetic base and arms. The best standard indicators are made by Starrett. Some people prefer the +/- type for setups but the straight .01" scale with secondary dial is the most useful for general work. A good indicator is needed for setting up work on any machine tool and is often used for precision measuring of cuts.
Larger measuring tools or sets are often found for very good prices at sales or on-line. There are all types from precision block sets to granit tables and height gauges. Collect what you think you can make use of.
|- guru - Saturday, 10/20/01 15:45:41 GMT|
Machining Tennons Larry, I normaly do this in one pass starting from the end of the work with the tool set to full depth. However, the lathe must be heavy enough for the job AND the tool properly sharpened.
It is not hard to machine a 5/8" or 1/2" tennon in 3/4" square stock. The work should be close to the chuck but tennons as long as 3" can be machined. However, shorter is better. A 12" to 16" lathe is probably necessary for this job.
The cutting tool needs minimal shaping. HSS cutters are best for this type work. The leading edge that creates the shoulder and does most of the cutting should be straight with the tool and relieved downward about 7 degrees. The front of the tool should be angled back about 10 degrees and relieved on the front 7 degrees more than the toolholder angle. The corner where these two meet should have a healthy radius of 1/32 to 1/16". Smoothly blend the radius with the sides of the cutter using a stone.
The top of the tool can be left flat or relieved back away from the leading edge. It takes a heavier machine to handle the flat top tool but you get a longer tool life when shapening. When grinding a top bevel it should NOT lower the leading edge or create a "hook". Try to avoid grinding right up to the leading edge or to just barely grind to the corner. Back relief is created by the use of the proper tool holder. Grinding back relief in the tool shortens its useful life. Other cuts such as "chip breakers" and secondary relief just make a mess of the tool and rarely do any good.
The above grind is shown in "How to run a Lathe" (I think) and differs from what MACHINERY'S HANDBOOK recommends. In general the less grinding and the simplier the tool the better.
With the tool set to make a square corner find the closest you can safely work toward the chuck. If you have a carriage stop put it here. If you use a stock stop set it for the end of the work to give the full length of the tennon between it and the carriage stop. Otherwise take a measurement for the stock overhang and set an adjustable square to use as a guage.
Then, taking light cuts on the end of a test piece set the depth of cut to create the diameter tennon needed. Lock the saddle in this position.
Now, if you have everything set right (tool height at center?) you should be able to lean into the work and cut a tennon in one pass. When cutting this heavy a cut you normaly need to hand feed the carriage unless the lathe has exceptionaly fine feeds. Normaly you do this by feel keeping a steady pressure on the handwheel.
When you hit the carriage stop, pause for one revolution and then back up the carriage as quickly as possible. Due to spring in the work and tool holder there will be a spiral back cut. For this class of work it can be ignored as long as the diameter of the tennon is correct.
If you are using a standard 4 jaw chuck mark two jaws at 90 degrees with paint. Once the first piece of stock has been trued up us the other two jaws to remove and insert new work. This should remain accuarate enough for tennons. If you can visibly see the runout then you will need to reset the jaws.
There are 4 jaw scroll chucks that are very handy for this type work but they are fairly rare. You can also make a set screw clamping fixture with a square hole for this type work. I think I show one in an iForge demo.
|- guru - Saturday, 10/20/01 16:50:16 GMT|
Chucking Work Something folks overlook when using four jaw chucks is alternating the direction of the jaws. For rectangular work you turn two opposite jaws so that the tall step is outward. Then the work can set on the steps of these two jaws while the others simply clamp from the outside. I have even had cases where only one jaw was reversed.
Some old four jaw chucks have holes and slots that can be used with clamping furniture OR for bolting on fixtures in place of jaws on one side of the chuck. When doing this OR when turning odd shape work, consider bolting on balance weight. For low speed work this is not necessary but it is needed for high speed work or anytime you notice the machine vibrating.
|- guru - Saturday, 10/20/01 16:59:12 GMT|
I have a client that I have made seveal Celtic crosses for simerlar to the ones on the IForge page this client would now like some made from Bronze. I have only limited knowledge of bronze (using it only for babit bearings) I would like to know what bronze is suitable for forging 1/2 X 1/2" bar stock is what I use for the cross
is silicon bronze the best suitable?
are there better available alloys?
is pure bronze forgeable?
|Mark Parkinson - Saturday, 10/20/01 19:34:58 GMT|
How do you figure the length and thickness's? of rivets to be used for a job? Is there a formula? Always before I just decided what looked good aand the length I needed but I always left too much to buck.Say to a piece of 3/4" to 1/2" sq stock?
THanks Robert Smith
|smitty7 - Saturday, 10/20/01 20:48:11 GMT|
Brass and Bronze: Mark, The best is forging brass,
alloy 377 or UNS C37700. Then there is architectural bronze , UNS C38500.
Brass Bronze FAQ
I've wanted to do the same thing and have some 1/2" square brass of some type here somewhere. The trick is not to overheat the brass/bonze and have it fall apart. A de-tuned gas forge works very well. Working in low light helps as you can just see a slight glow at working temperature. However, you cannot see the glow in bright light. On clean stock there is a slight blush on the surface but it is difficult to see on repeat heats.
Once heated and forged hot the brass/bronze is also annealed and will work cold to a degree. It is still workable where steel is usualy not. Small sections and points tend to shear and split like cold working the same in steel.
|- guru - Saturday, 10/20/01 21:02:34 GMT|
Rivets Robert, depending on the style of head it takes from 1.5 to 1.75 diameters to head a rivet depending on the style of head. Add up the material thickness then add the rivet head length.
In most cases a rivet or bolt should not be more than 50 to 60% of the material width. So for 1/2" square a 1/4" or 5/16" rivet would be the right size. 50% is best.
For flat stock then a rivet one size larger than the thickness is a good size. However, if you are joining structural flanges there are guidelines for multiple rivets in MACHINERY'S HANDBOOK and the AISI Steel Construction Manual.
If the material is swelled at the hole from hot punching then you can go 75% (a 3/8" rivet in 1/2" stock spread to about 3/4" wide). If you slit and drift the hole so no material is lost at all then the rivet could be bigger than the original material size (for decorative purposes).
When connecting two different sizes of stock it is best to upset or spread the smaller stock to the same width as the larger stock.
|- guru - Saturday, 10/20/01 21:33:27 GMT|
KOHLSWA ANVILS We are looking for folks that have relatively new KOHLSWA anvils made in the 1990's. For a time in the 1980's they had some quality problems and we are looking for folks that have experiance with new ones in large sizes. Let us know how you like your late KOHLSWA and how it compares in hardness to other anvils.
|- guru - Saturday, 10/20/01 21:42:44 GMT|
Is "How to run a Lathe" on this site or is it a book.
Thanks for your answer.
A friend said Josh Greenwood was giving a demo Nov. 10. I was wondering if you are going?
|- l.sundstrom - Sunday, 10/21/01 13:34:55 GMT|
How to Run a Lathe was published by Southbend back in the thirties. I'd be more specific but I have either misplaced my copy or loaned it out. . .
It is a softbound booklet covering the basic operations of a Southbend (a standard) engine lathe. It includes instalation, control operation, tools and attachments as well as the basics of machining.
Old Lathes: It is common for old lathes to have worn the base of the tailstock so that it is lower than the spindle. To align it:
|- guru - Sunday, 10/21/01 15:02:43 GMT|
I am wondering if you could give me some direction in finding a blacksmith who would be able to create 4 vent covers for a fireplace. My husband and I recently covered a brick fireplace in cultured stone and would like to have rustic looking wrought iron(or what ever material you would suggest) covers for the four vents on the front of the fireplace. I have seen these used on several firepaces but in checking with fireplace and woodstove dealers I have found that this is not a standard item. No one has been able to give me any direction.
I appreciate any sources you could recommend.
|Bobbi - Monday, 10/22/01 15:03:33 GMT|
Looking for Blacksmiths: Bobbi, Check the ABANA-Chapter.com page (on our drop down menu) and look for a group local to you. They should be able to put you in contact with someone.
You can also try our links page(s) and the Blacksmith's Webring (also on our drop down menu).
The reason you want a local smith is that each opening will need to be carefully measured for size, squarness and obstructions (the stone surface). Even when the vents are part of a built in fireplace it is common for the stone or brick facing to distort the sheet metal ducts making each one different. If the grates do not need to fit into the vents but just cover them then this may not be important.
Note that what you may have seen is old floor grates. These are fancy castings and are not a type of work you want to ask a blacksmith to reproduce. The old style grates are often available as reproductions from architectual hardware suppliers. The originals were cast-iron and new ones are usualy cast aluminium.
Most blacksmiths should be able to produce very nice grates for you. However, you are asking for custom handmade work, not a production item. Expect to pay for the artisan's time.
|- guru - Monday, 10/22/01 16:54:16 GMT|
Bobbi, Know about Old House Journal? They probably have a slew of ads for the sort of replicated old-timey grille/register/grate/heatolator thing Jock's referring to. Check it out at: http://www.oldhousejournal.com/
|miles undercut - Tuesday, 10/23/01 02:02:14 GMT|
I am a 45 year old woman who is interested in aging a few tin pieces that I have for my home. What could I put on it that would give it a blackish tone? This is purely for my personal pieces at home. Not sure if this is the place to seek help. Thanks.
|Pat - Tuesday, 10/23/01 12:56:31 GMT|
Blackening Tin Pat, it depends on the "tin". "Tin cans" still have actual tin, the elemental metal plating steel, the actual base metal. However, some now have plastic coatings inside. Other sheet metal labled "tin" is generaly steel sheet that may be coated with zinc (galvanizing).
The reason for these platings is corrosion resistance and they are resistant to most mild chemicals. To blacken either requires mixtures of strong acids with lead compounds or other nasty chemicals.
The best method is to etch the surface so that paint will stick and then use black spray paint (flat or gloss).
If you soak the parts in vinegar the protective coating will be etched OR removed. Length of time varies with the condition and type of coating. In some cases they will become blackened somewhat. Rinse the parts with a baking soda (sodium bicarbonate) solution to neutralize the acid then rinse with water and dry.
On good tin the vinegar may not work well. Try common liquid bleach. This is very aggressive when used on metals and is often used for "instant" rust. Thin "tin" may be disolved entirely so keep close watch. Either a straight or diluted solution may be painted on repeatedly. Be sure to wear protective rubber gloves and work outdoors where there is plenty of ventilation. Safety glasses are also recomended. After the surface is corroded to satifaction rinse with clear water then a 50% solution of vinegar to neutralize the bleach followed by a rinze and a solution of baking soda to neutralize the remaining acid.
Again, you may be happy with the results or you can paint the resulting surface. It is often best to take a scrap ad do a test before doing the actual work. Time soaking periods to get consistant results. However, vinegar is quickly "killed" and repeat uses of the same bath will take longer and longer to get the same results and will eventualy stop working altogether.
When finished be sure to carefully dispose of the waste chemicals. They now contain disolved metals and are toxic. As I mentioned there are other methods but these require much more toxic and often hard to obtain chemicals.
Optionaly the tin can be roughened with fine sandpaper and painted. However the paint may not hold up for exterior use. Also remember that the methods above are removing the rust proofing of the metal and may need more protective coating. If you like the "aged" results you may want to use a clear laquer coating to reduce further corrosion or rusting.
|- guru - Tuesday, 10/23/01 15:11:22 GMT|
what is "diamond cut naval bronze"? This mat'l is called out
on a drawing we are redrawing to cad. Is there an substitute?
|Jim McFall - Tuesday, 10/23/01 16:11:43 GMT|
Diamond cut naval bronze Jim, A quick search on Lycos returned the following:
Diamond Cut Naval Brass Plate
This is ultra-flat precision machined plate. The "diamond" may refer to the cross hatched finish produced when a flycutter is running absolutely true and the trailing cut does not remove the leading edge cut marks but leaves its own marks. The result is a square or diamond hatching look in the middle of the cut.
From SURFACE FINISHES CO. INC.
Diamond machining is a process in which a single point diamond is used as a cutting tool, in a fly cut or turning operation. The process takes place with equipment using highly accurate gas bearings. . .
This is also what my machining references call "diamond machining".
Both definitions indicate a very flat surface. The diamond machining generaly produces an ultra smooth opticaly clear surface. Are there any other surface finish specs on the drawing?
The item or drawing should have some other hints about the type of finish needed. Opticaly flat with a briliant finish is pretty special. The link at top to Bearing Bronze Ltd. does not indicate the brilliant finish normally produced by diamond machining but may be a simple oversight. If I were you I'd contact them and ask.
Also note that it is common to confuse Naval Brass and the term "Naval Bronze". See our Brass Bronze FAQ. Be sure to include a UNS alloy number along with correct surface finish specs.
A search of Thomas Register did not produce usable results.
|- guru - Tuesday, 10/23/01 17:36:50 GMT|
Viruses in the Blacksmithing Community: A couple old viruses are still running through the blacksmithing community, TROJAN_SIRCAM, PE_MAGISTR.B, SnowWhite.
All of these require you to open the attachement OR let your Microsoft mail program automaticaly open the attachments.
Never open attachments that are executable (exe, com, bat, pif). Attachments that have two extensions such as zip.exe, txt.pif are almost always virus files. Joke.exe and midgets.exe are the executables for SnowWhite.
Some viruses prevent you from accessing anti-virus sites. One, Snowwhite always uses its own return address (= hahahaha..) so that friends can not warn you that you are infected. AND there are many of you infected judging from the number of SnowWhite generated mails I get.
If you do not run a fresh version of an anti-virus system or your system has not been scanned for viruses recently, PLEASE go to the following address (if you can) and run the free virus scan.
Trend Micro Housecall
It takes several minutes to download the program files depending on the speed of your connection (be patient) and may take up to an hour to scan all the files on your system depending on the number of files on your system.
If you cannot access the above address then there is a good chance that you have a virus that is preventing access to a number of known anti-virus sites. In this case try again later as these sites are VERY busy. If you still cannot get through then you will need to purchase an up to date anti-virus program to scan your system. In many cases you may need to reinstall your OS (windows. . ) and a new copy of wsock##.dll or exe.
Like our new heightened alertness to unusual postal mail and strange behaviours, we also need to be alert to computer viruses. These ARE a form of cyber-terrorism and it IS possible for them to slow, clog or make the Internet unusable. Not taking responsibility to secure YOUR system and check it for viruses makes you part of the problem.
Computer viruses are not just a nuisance. They cost our economy time and money and are security threats. Many such as SIRCAM send copies of your personal files (letters, accounting and tax information) to everyone on your address book and every person from every address book on your network (if you are on one). Other viruses let hackers use your computer for Denial of Service (DoS) attacks on whatever server or web-site they choose. These attacks can shut down a server OR cost the owner so much in traffic fees that it bankrupts them. THEN, there are the viruses that return passwords to the virus author OR give the hacker access to your system.
Computer viruses would not be a problem if everyone took care to be aware of them and check their systems occassionaly. PLEASE scan your systems.
|- guru - Tuesday, 10/23/01 17:55:26 GMT|
could you recommend a free anti virus program. thanks
|harry funk - Tuesday, 10/23/01 20:24:35 GMT|
Harry, see link above. Its free to use and when used on-line will ALWAYS be the most up to date version. They also have a 30 day free trial for installation.
Keeping your anti-virus software up to date is very important. New viruses come out almost weekly. The programs do not detect anything "generic" about viruses, they look for a signiture or pattern for every known virus. So, several month old anti-virus software will not recognize the newest viruses which are also generaly the most active. Many people install anti-virus software or use what came on their machine and then don't bother to update it for years. . . Then they get upset when their machine gets infected by a new virus.
Remember, anti-virus software is relatively dumb and only recognizes viruses that it has been TOLD how to recognize. There is often a two to three week delay between when a new virus is launched and the newest update is available. This means that YOU are always your only first line of defense against new viruses.
|- guru - Tuesday, 10/23/01 21:02:10 GMT|
Hello, I have been blacksmithing for several years now and I would like to step up production by purchasing a power or Air hammer. I am leaning more towards the air hammer because I have a large air compressor and I believe the air hammers are a bit quicker. My question for you is this: I'm trying to decide between the Big Blue and the Bull Hammer and I was wondering if you had any advice or preferably any experience with either of these two hammers? I will use the hammer primarily for drawing out stock and texturing steel with spring swages exc.
|Dan - Wednesday, 10/24/01 14:13:42 GMT|
Air Hammers Dan, These are both good machines. The Big Blue is considerably less expensive than the Bull for the same capacity. The Bull has numerous proprietary control features while the Blue has a deep throat giving it a capacity for doing sheet metal work and sculpture. Both use standard components that can be replaced through the OEM or by the part maker.
I've run both machines and the control is similar. As with all machines it takes some practice to get used to the exact characteristics in order to do sophisticated detail work.
Both machines will do what you want. Both are made within a few miles of each other so shipping per pound should be similar. If you are close enough to Asheville, NC you could visit the makers and try out the machines as they are quite convienient to each other. The Kaynes run a busy blacksmith shop and run 4 of their own hammers and would be glad to demonstrate them for you. Both machines are often in use at blacksmith conventions if you want to see them close up. You can often avoid shipping costs by picking one up at a show.
In the end its largely a matter of style and which machine you like or is in your buget. Although I wouldn't turn down either machine I personaly like old heavy iron (Nazel, Bement, Bradley, Fairbanks). But many people don't want to deal with old machines and lack of factory support. . lucky me!
|- guru - Wednesday, 10/24/01 15:37:38 GMT|
Dan: The Bull "and" Blue are good hammers. Big Blue is rod down and Bull is rod up. I think the Bull needs more air than the Blue. Needs it to push up the heavier ram. Bull also has a much more complicated linkage system. The control on both these hammers is very, very good. To me the dies on the Blue are small. If it wasn't for the price difference and a possible extra compressor purchase, this would be a Ford, Chevy conversation.
|Pete/Raven - Wednesday, 10/24/01 16:33:50 GMT|