Sunday, July 31, 2011

Do your Thinking in the Fire




What doses that mean? To me it is a strategy similar to playing chess in which success depends upon thinking several moves ahead - a mental step set. The movement of the iron won’t be as tricky as a chess opponent but I need to have a contingency plan if my next move doesn’t accomplish exactly what I intended.


It means having a clear idea of what I want to achieve on this heat. Where does the heat need to be isolated? Does this require a convenience bend or selective slack tub cooling? What color heat is needed? Is the hammer and ancillary anvil tools set up properly?


It wasn’t always the case, but today when I plan a forging session for a project I usually have a written strategic plan or drawings detailing the sequence of steps I imagine. I divide each step into a one-heat-at-a-time tactical plan.


In order to learn something new, some time must be set aside for experimenting and doing test pieces so when it comes time to do the project I don’t expect to be surprised by some bummer problem. On the occasions where that happens I quit and move to another project. A fall back and regroup tactic is best done when the fire is out. And it is one reason I carefully layout somewhat more than I expect to accomplish in the allowed forging time.


http://www.persimmonforge.com/

Saturday, July 30, 2011

Work Which Tells a Story






Over ten years ago I was asked to make a gate which would mount in the doorway between kitchen and dining room of a home. The owners wanted the canine members of the family confined to the kitchen space so visitors, especially young children, wouldn’t be bothered by them.


After deciding the technical details, discussion turned to the design theme and how it might reflect things meaningful to the owners. The clients were intellectual people with backgrounds in psychology and physical therapy and avid readers. Eventually we settled on an interpretation of the opening lines of William Blakes’ Auguries of Innocence. It has served as inspiration for countless other artists.



To see a world in a grain of sand

And a heaven in a wild flower,

Hold infinity in the palm of your hand

And eternity in an hour.


The gate was free to swing both in and out and had a spring catch like the old fashioned garden gate so the over all look might be appropriate to a garden entrance. The sunflower is a natural for Kansas although the poem isn’t specific about the wild flower. Symmetry could suggest a Rorschach inkblot test which a psychologist might appreciate.


With the frame constructed and fitted and these ideas floating around, sketch work was chalked out on the layout table and test pieces were done. The design was necessarily tight because a 3” code was specified based on the dogs snout shape.


Eventually it all came together with the poem guiding the way and was installed and worked well. I got to visit it from time to time which is unusual for most of my projects. Today, I wouldn’t do it the same way and my skills have improved quite a bit but every work is fixed in its own time.


The family mowed to another state after retirement and the gate went with them. They kindly sent me a photo of it in place in its new home. I hope to visit it there eventually and the friends too, of course.


http://www.persimmonforge.com/

Thursday, July 28, 2011

Vise Handle Bumpers




This is a little safety device I’ve used so long it is almost invisible to me. My big Trenton-Fisher is at my main work station. This large vise has a handle which is massive enough that if it falls in the vertical orientation a serious pinch can result if the thumb-index web skin is caught by the terminal ball.


After such a close call I decided to create a bumper by wrapping a leather strip around the handle just below the ball. Later I added some silicone adhesive and even later used duct type tape. I use the vise every day and from time to time the bumper must be refurbished to remain effective.


There are five other post vises around the shop and none of them have handles heavy enough to present enough threat to require bumpers. One has a sinuous “S” curve bent in the handle which seems to have been added by a previous owner and is somewhat effective in preventing the potential free fall.


http://www.persimmonforge.com/

Wednesday, July 27, 2011

Getting Discouraged




Kristopher Skelton operates Alchemy Forge. I think his primary interest is blademaking. I’ve never met him but have enjoyed reading his blog and viewing the website galleries.


In the blog I came across a second, or third, hand narrative which I feel has some wise advice as follows...


MONDAY, MAY 16, 2011

A reminder...


This was posted at Don Fogg's bladesmith forums by Alan Longmire, attributed to Ira Glass:


What nobody tells people who are beginners — and I really wish someone had told this to me . . . is that all of us who do creative work, we get into it because we have good taste. But there is this gap. For the first couple years you make stuff, and it’s just not that good. It’s trying to be good, it has potential, but it’s not. But your taste, the thing that got you into the game, is still killer. And your taste is why your work disappoints you. A lot of people never get past this phase. They quit. Most people I know who do interesting, creative work went through years of this. We know our work doesn’t have this special thing that we want it to have. We all go through this. And if you are just starting out or you are still in this phase, you gotta know it’s normal and the most important thing you can do is do a lot of work. Put yourself on a deadline so that every week you will finish one story. It is only by going through a volume of work that you will close that gap, and your work will be as good as your ambitions. And I took longer to figure out how to do this than anyone I’ve ever met. It’s gonna take awhile. It’s normal to take awhile. You’ve just gotta fight your way through. POSTED BY KRISTOPHER SKELTON

http://alchemyforgenet.blogspot.com/2011_05_01_archive.html


Being able to recognize good work and appreciate the beauty of fine craftsmanship and design is necessary yet not sufficient to producing such work. Practice, practice, practice is essential. Most things worthwhile are difficult to achieve and require dedication, discipline and persistence. I don’t think I have seen any masters who aren’t perfectionists.


For most of us the ideal is elusive and just beyond our grasp so each instantiation of our effort is a bit disappointing and we see how we might do better. Take a deep breath. Take another heat. Take another run at it.


Perhaps it was the word alchemy that set the environment for me to detect and connect the theme of striving and it reminded me of Goethe’s story, Faust. This tale is based on the medieval alchemist and magician Johann Faust, and in it Goethe concludes that man’s salvation lies in his striving and action. He observes that to err is human and as long as one is doing and striving, salvation is ultimately assured. In this metaphor success or satisfaction might better substitute for salvation.


http://www.new-wisdom.org/cultural_history2/6-romanticism/goethe.htm


http://www.persimmonforge.com/

Tuesday, July 26, 2011

Get a Grip




I heard an investment adviser say, “You can’t have too much money.” I’m not sure, but, I’m betting he didn’t have much trouble finding people willing to test that proposition.


I do know I never seem to have too many clamps. My favorite is the original Irwin Vise-Grip 12” large jaw locking pliers. The long nose style and angled long nose and locking C-clamps are handy too.


I don’t often have a project large enough to get out the heavy duty screw C-clamps, but, when I need them, I need a bunch of them. Individually, large new ones are pretty expensive - in the $50 neighborhood, but at auctions they are often a bargain. I picked up a box of about 20 a year ago for $25 total.


Even less often I use slide bar clamps. I especially like a heavy antique furniture clamp I found in an antique store years ago.


In the early years I sometimes had to go to the store and get another clamp or two for a job. I got a few more when we got to a job site an hour away and found we forgot to pack the clamps. Baring another slip-up like that I may finally have enough now. It would be interesting, but too much work, to gather them all up for a count. They are widely distributed around the shop and ought to be left alone because they got where they are for a reason.


http://www.persimmonforge.com/

Monday, July 25, 2011

Curious Inventor


I came across this site and thought it might be useful to other blacksmiths so I’m posting it.

http://store.curiousinventor.com/guides


It seems mostly to be designed for interested in electronics and electronic hardware design. There are several reference guides which are more general.


http://store.curiousinventor.com/guides/Metal_Working/Screws


http://store.curiousinventor.com/guides/drill_speed


http://store.curiousinventor.com/guides/tap_drill


http://store.curiousinventor.com/guides/Drill_Letter_and_Number_Decimal_Cross_Ref


Here is another curious site offering many innovative materials for inventors:

http://www.inventables.com/


Check them out. Nothing ventured - nothing gained.


http://www.persimmonforge.com/

Sunday, July 24, 2011

The Tweakers




Quite a few years ago, probably 2002, I was at a Rocky Mountain Smiths Conference and saw a tool in the silent auction labeled "Tweaker." It was a nicely forged and finished tool which had a blade similar to a slotted screwdriver and a "t" handle. It looked handy and when I returned home I forged several from 1/2" 5160 coil spring stock.


Sometime later I heard Tal Harris use the term "tweak" and question whether he should, for correctness, say "tweakify."


I checked a dictionary to confirm that tweaking refers to fine-tuning or adjusting. Tweaks are any small modifications intended to improve a system. Also think, alter, modify, refine, etc.


For the group image, I laid out the three tools at my primary work station. There are several others throughout the shop. Honestly, I will have to say they are mostly just used to pry something loose rather than adjust. I find them one of the most useful small tools and haven’t damaged a screwdriver blade in a long time.


The coil spring steel has held up well. The tips have been made in several shapes, oval, flat and pointed and the blade thickness varies. Originally, I probably made each when doing some specific repetitive project. The tips of some have been dressed a few times.


As I recall, most were made with torch heat. A little ten minute job which seems well worth the effort.


Happy Tweaking or Tweakifying.


http://www.persimmonforge.com/

Friday, July 22, 2011

Air Mobile






When I was stationed at Fort Benning back in the Vietnam War days the high five greeting was “Airmobile!” or “Airborne!” The Air Mobile warfare concept was designed around the UH1B "Huey" helicopter, the workhorse of the concept. In those difficult years the 1st Air Cavalry Division and the 101st Airborne Division formed the bulk of mobile forces, as I recall. But I digress. That wasn’t the kind of air mobile threat I was originally thinking about.

Blacksmiths, by necessity are exposed to some nasty airborne particulates, coal dust, smoke from burning carbon fuels, dust from abrasive operations, finish and cleaning chemicals, welding fumes, and more. I was pleased to discover, when I started associating with this diverse group of talented people, that they largely avoid adding tobacco smoke to that mix.

Good ventilation is always recommended in the workspace. Ideally, masks and respirators would be as easy to wear as eye, ear, hand and foot protection, but that just isn’t the case. Even with doors open, fans can help. Every time, essentially monthly, I change the furnace filers on the shop heating/cooling unit it is impressive to see what has been trapped.

We are taught that some airborne molecules are more dangerous than others. Lead, and asbestos have been determined to be such threats that they are being removed from our US environment on an ongoing basis and not added anymore. Correct me if that’s wrong. Heating metal hardware parts can liberate zinc and cadmium vapor and heating copper alloys puts another group of potentially dangerous ions into the air. Pickling galvanized hardware helps reduce the zinc hazard.

Another potential concern encountered in gas forge construction is the refractory liner - both fiber blanket and castable materials. High temperature sealers help reduce shedding of particulates.


The health effects of many of these poisons and irritants are largely irreversible so appropriate vigilance is indicated. We’re all going to die of something but there is a lot of distance between our obligatory demise and suicide. Be Careful.

http://www.furnaceindustries.com/Images/msds-kaowool-blanket.pdf

Chronic obstructive pulmonary disease - Wikipedia, the free ...

Metal fume fever - Wikipedia, the free encyclopedia

Silicosis - Wikipedia, the free encyclopedia

Asbestosis - Wikipedia, the free encyclopedia

1st Cavalry Division History - Ft. Benning, Airmobile 1965

http://www.persimmonforge.com/

Thursday, July 21, 2011

Tractor Seat Stools



While my favorite scrap yard was still in operation I kept my eye open for tractor seats among other things. I could buy them for next to nothing there. If I saw one in an antique store the price was considerably multiplied so I left those for collectors.


I made three shop stools using tractor seats. They are all a similar style with four legs, scroll feet and a heel ring. The heights vary from 21” to 24”. One is used for TIG welding. One is used with the fly press. The third is a wanderer which moves around from place to place often acting like a table.


If I were making another stool just for utility I might use a plow disc for the base. A disc doesn’t present an edge to kick and it wouldn’t snare an extension cord as the scrolls do.


Doing an image search will capture quite a few interesting designs. I saw one with a single welded chain post. It looks cool but must require some considerable faith in the welders’ ability.


http://www.persimmonforge.com/

Wednesday, July 20, 2011

Witness Marks









Yesterday I started a small sculpture project which required seven pairs of elements. The pairs are similar but not identical so I stamped reference numbers to keep the pairs matched. This one example of what I call a witness mark. They may not be readily apparent in the finished piece but theoretically a forensic examination might reveal them.

After a little checking I found this phrase can be used to express quite a range of subjects. The online Double Tongued Dictionary, which describes itself as “a lexicon of fringe English focusing on slang, jargon and new words,” gives this definition:

“witness mark n. generally, an intentional, accidental, or naturally occurring spot, line, groove, or other contrasting area that serves as an indicator of certain facts; in geography and surveying, a blaze, cut, hole, paint splash, or message written on a post, tree, rock or other guide to indicate a boundary, feature, or significant point on land, especially on a witness post; in construction and manufacturing, a line, groove, score, notch, cut, or written indicator made on the surface of material to impart information, such as where to cut or join; in forensic investigation, a surface groove, smear, stain, abrasion or other feature that can serve as evidence.”

I’ve used the term a long time. I think I learned it when I was doing woodworking. I distinguish it from a “process mark” which may be detected on close examination but not intentionally placed - just a surface mark related to the tooling used.

I make witness marks mostly to demonstrate the proper alignment of a tool or jig. I remember watch Tom Clark forge a hardy and fit it to the anvil - it only fit in one orientation so he made a mark on the side which should face the horn. I call these “registration marks.”

I also don’t think of transient marks as witness marks. Silver pencil, paint marker, layout fluid, presto pen and soapstone marks are quite useful but disappear as the work progresses and they are no longer helpful. Interestingly, I don’t know if there is really a proper name for that group but I’m going to call them “layout marks”. Even a center punch mark, which could be a permanent thing, disappears if it serves as a place where a hole was drilled.

Likewise, I think of touchmarks as being in a separate special category as well as the numbers stamped to indicate a pieces’ place in a series.

So, what makes a good witness mark? This is the rhetorical question that keeps me going. Usually, I use a punch. Usually the punch has a sharp round tip. Usually it is a center line mark. I was taught that a sharp square punch mark is easier to see in the fire than a round one but I really can’t say it has made enough difference for me that I make square punches which are more tedious to sharpen.

If I think I will have a hard time seeing the mark in the fire I will use a round punch to make a frog eye, my favorite - see the images, or use a gate fuller or guillotine tool to place shallow fuller marks on opposite sides for reference. Of course, these need to be used in areas where they will disappear with subsequent forging.

A scribe is nice for precision cold work as are transfer punches. Sometimes a chisel cut works well, sometimes a shallow file or saw cut or a zip disc nick. Occasionally I just put bars in the Hossfeld bender and make a slight kink to mark a transition spot. As John Wayne said in "Hondo”, "A man ought'a do what he thinks is best."

So, I think the name of the set is Witness Marks and the members of the set are all those other examples. At least that’s what a splitter would say.

I found this by searching for witness mark but I would call it an illustration of process marks: Cute animation

http://www.kanabco.com/vms/glossary/w/witness_mark.html

http://www.persimmonforge.com/

Tuesday, July 19, 2011

Analog Math



Many times a day I pull out a pocket steel tape and measure something. Usually this is a single and quick comparison as a rigorously accurate value isn’t required. If fit is a consideration, particularly as the economic consequence rises, I am more careful and often follow the “measure twice and cut once” proverb. Even more insurance of accuracy can be achieved by comparing the value I measured with that which a helper measures.

Sometimes I tend to forget that all measurements are approximations or estimations. The variation in value is contributed to by the instrument I use and the characteristics of what I am measuring.

Less often, yet frequently, I use some analog, or non-integer, method of measurement. This is even a cruder approximation or guesstimate but often adequate. For instance I may balance a bar to determine the center of mass. If the bar is of nominal dimension the center of mass will be pretty close to the center of length.

Alternatively I can use a pair of dividers set to guess half the length and scribe off lines starting at both ends and split the difference. This is just like the bisecting a line method we learned in plane geometry. Using a pair of dividers made to mark the golden proportion lengths is another useful analog design device.

When several equal length bars are involved I often find the center point by putting a presto pen mark at the guess point then flipping one bar end to end and splitting the difference between the two marks.


















Laying a leather strap on a bar and then folding it in half and marking is another quick way to guesstimate center.

Years ago I acquired some strips of lead about a 16” thick and 3/8” wide a couple of feet long which I use to measure circumference of small objects. Soft wire solder has also been recommended.





I have an antique traveler but it just hangs for display. I suppose if I did a lot of work with circumferences that would be different.

Occasionally if I just need to transfer a length measurement under 3 feet I will use a slide bar quick-clamp as a caliper. It will hold long enough without slipping to make the comparison measurement.

Finding the center of mass, “gravity”, by hanging is a trick I know but don’t recall ever having to use. It is similar to finding the center of a circle with a center finding tool. We use an analog method when locating the center of a rectangle by drawing lines from opposite corners and observing the intersection. But when I check a fabricated rectangle for “square” I use a steel tape or folding metal rule corner to diagonal corner to check the numbers.

I’m pretty sure I’ve skipped a lot of examples of this sort of thing. Outside my blacksmithing realm, digital conquers all - electronic caliper, calculators, etc. I haven’t touched a slide rule in many years.

Integers and fractions have their place. Sometimes I need them, sometimes I don’t. That reminds me of the Mounds and Almond joy candy bar ads of the 1970’s. "Sometimes you feel like a nut, sometimes you don't.”

Hanging to find the center of mass:

http://www.fas.harvard.edu/~scdiroff/lds/NewtonianMechanics/CenterofMass/CenterofMass.html

Terms:

http://en.wikipedia.org/wiki/Accuracy_and_precision

http://www.persimmonforge.com/

Doing Things Wrong



I once heard a person say, "Nothing is ever worthless. It can always be used as a bad example." Maybe it should be classified as a good example of bad work. So it is with my collection of mistakes and bad ideas. Each specimen is an illustration of how not to do something.

The early learning years produced a few five gallon buckets full of pieces which missed the mark. From time to time I decide to clean up a bit and go through one of those buckets to see what could be reworked, scrapped or preserved as a bad example.

Also, from time to time I look at the old test pieces hanging on the walls and take one down to show or look at for a design idea. As a general rule if it is hanging on the wall there is something wrong with it, otherwise, it would be somewhere else offered for sale. If it illustrates an interesting defect I may keep it as another bad example. Sometimes I make another example done more artfully than the old one to show the difference.

A while back a blacksmith friend visited and wanted an idea for a simple demonstration he was scheduled to do. I looked up and saw some old scroll forms and took one down thinking I would just give it to him to use in his show. I noticed it had a kink in the radius near the end of the arc and pointed that out to him. Then I thought how that could be used to illustrate how easily the eye can spot such a defect. It is actually easier to see if the scroll is held up against a plain background and the negative space inspected. The break in the smooth line is easily apparent whether a kink or a flat spot. Now that makes the scroll pulling demonstration more interesting.

There is intellectual knowledge and there is visceral knowledge. The intellectual knowledge can be obtained vicariously without actually learning from experience and sometimes that is best if the activity would be really dangerous. But usually learning from experience sticks best with me.

“Experience is a hard teacher because she gives the test first, the lesson afterwards.” That is according to Vernon Sanders Law. When I was doing the first experiments with my newly completed hydraulic forging press, I decided to try and cut a piece of mild steel on a cutting saddle with a handled hot cut. I failed to appreciate how much more powerful this machine was than my 50 pound power hammer and I didn’t get my foot off the pedal fast enough. The hot cut went through the workpiece and the cutting saddle and snapped off the chisel tip. Wow! I won’t ever try that again. Now that’s visceral knowledge.

Some times it is instructive to intentionally do something wrong as a part of teaching. Working a piece of real wrought iron too cold will easily reveal the fibrous nature of he material. Showing how important it is to get a punched and drifted hole perfectly centered by doing one off-center is a clear illustration. Showing how not getting a bolster sized close enough to the size of the drift will allow metal to suck down the hole is an other example. There are many possibilities and I’ve probably done most of them.

Take another heat.

Monday, July 18, 2011

Black Annealed #9 Wire




Locally I can only find 16 and 14 gauge black annealed wire. A friend in the Denver area brought me a 100 pound 12 gauge roll. I went to the internet to locate a source for 9 gauge but needed only 10 pounds or even less.

After more difficulty than I imagined I found what I needed at this address:
http://www.wildlifecontrolsupplies.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=NWS001&Product_Code=SPSW910&Category_Code=

The wire was to be used to simulate sigma and stamen elements in some botanical motifs. Apparently this wire is also used in setting animal control traps. The product advertisement stated that is was used primarily for positioning snare loops. Product Code: SPSW910 Price: $16.95 Shipping Weight: 11.00 pounds

So there is a tip for anyone having difficulty finding this metal stock. While I was roaming about I found that black annealed wire sold for rebar ties is usually 11 to 15 gauge and baling wire is 9 - 14 gauge. The baling wire is available in 1018 and 1008 alloy.

I could find a number of sources for 100 pound rolls of baling wire but I didn’t want that much. Also I could have done what I have usually done - buy #9 galvanized wire, remove the zinc by pickling in hydrochloric acid then anneal in the gas forge. This is doable but it seems like a long run for a short slide.

Sunday, July 17, 2011

My Asymmetric Jaw Vise






About 10 years ago I bought this handy tool from a friend who was a longtime blacksmith and tool collector. He said he had only seen four of the vises with a pivoting rear jaw. I was looking for a heavy vise which I could mount lower than my post vise. It is mounted on a concrete filled barrel at my primary work station. It stands a few inches higher than the Peter Wright anvil and a bit lower than the Trenton-Fisher double screw vise.

Most of the time I use it with the jaws parallel but it does work well for gripping slightly asymmetric things. I really haven’t tried to determine the maximum angle of effective grip.

Of course any parallel jaw vise can be fitted with a jaw insert which will pivot to grip asymmetric items. I made one a long time ago when I was making some soft jaw inserts and inserts with a larger radius edge. I don’t recall ever using it though.

My vise was made by the Reed Manufacturing Company of Erie, PA. Patent dates of 1908, 1912 and 1914 are shown in the casting. The company is still in business making tools including many kinds of vises.

This vise has been most useful because the jaws can open to 8.5” with the slide fully engaged. The rectangular slide surrounds the main screw and not and keeps dirt and debris away from the threads.

I looked up some information about this unusual tool and was pleased to find the author of the article below felt the Reed vises were the best ever made.

Link to an excellent article about vises, their manufactures, restoring vises and more:
http://www.garagejournal.com/forum/showthread.php?t=62716

More vise discussion (there were 131 pages so far):
http://www.garagejournal.com/forum/showthread.php?t=44782&page=109

Link to another swiveling rear jaw vise - scroll down a bit:
http://www.practicalmachinist.com/vb/general-archive/vise-squad-pics-lets-see-yours-78814/index23.html

Saturday, July 16, 2011

Trenton-Fisher Vise Chain Repair




Several months ago, actually August 2009, one of the links on my antique Trenton-Fisher vise finally gave way. I took the chain off and inspected the break. It looked like it might be possible to fabricate another link but it might be tedious and time consuming to get it just right so I decided to look for new chain.

At the local farm and ranch supply store I found out that it was called steel detachable chain, also flat steel chain. It is called agricultural chain too in general, but there at least three subtypes. The store didn’t stock the size I needed and suggested I check with John Deere. The most valuable thing I took away was learning the proper name which I was able to use at John Deere.

I drove directly there and they were able to measure the link, look it up in their parts manual and order it for me. The minimum order was 10’ for $38.53 which included shipping and tax. There was the option for buying the chain link by link but time was going to be the biggest expense in the repair and if another link broke and I had to go through all that again it would really be a false economy.

Time flies. The new chain has been in use for almost two years and works fine. I’ve got enough extra chain to fix it again it if I need to do that. So all’s well that ends well.

Here are some references for anyone interested:

Chart showing how to measure a chain link to get the part number:
http://fcmason.thomasnet.com/viewitems/steel-detachable-chain/flat-steel-chain?

Some other chain sources:
http://www.thebigbearingstore.com/servlet/the-Roller-Chain-cln-Detachable-Chain-cln-Attachments/Categories

http://www.balsters.net/agroller_steel_detachablechain.html

http://www.macknair.com/miscellaneousparts.htm

6/27/12 Today I came across some more information about the vise in the Summer 2009 issue of Anvil's Ring on pages 39 - 41.

Friday, July 15, 2011

Swarf






As a kid my contacts with metal working were rather skimpy. I flattened tin cans and nailed them to carts and tree houses and we covered a knothole in a chicken house with a tin can lid securely screwed to keep out mice and snakes.



Bent nails were straightened using a claw hammer and a rock anvil. I cut some steel with a hack saw, did some filing and a little chisel work. All my was done cold and it wasn’t much fun. Wood, especially from orange crates, was the preferred material for building something. Any early tool using experience probably eventually pays off even with the price of a few smashed finger nails, blood blisters and water blisters.

It was pretty neat for me to watch someone with a drill press use a twist bit to go through steel cutting out the curly strips and chips. I never dreamed that amusing stuff had an actual specific name - swarf.

From http://www.merriam-webster.com/dictionary/swarf - Definition: material (as metallic particles and abrasive fragments) removed by a cutting or grinding tool. Origin: probably from Middle English swerf, from Old English geswearf, gesweorf; akin to Old English sweorfan to file away. First Known Use: 1565
For more detail see: http://en.wikipedia.org/wiki/Swarf

When I’m cleaning up the swarf today around the drill presses, band saws and cold saw I find a small rare earth magnet on a handle pretty handy. That’s what got me thinking about those childhood experiences with iron.

The brick street in front of our house had concrete curbs. The street sloped to the south where at the end of the next block rain water was captured in a culvert which ran under the Katy Railroad tracks. When we got a good rain sand would wash down and deposit at intervals in little sand bars near the curb. When dry the sand was a good place to mine for some small treasure, perhaps a coin. I found a bullet once. Besides something to dig with the favorite tool was a magnet. It was fascinating to see that quite a bit of the deposited grit was magnetic. It’s not really surprising though remembering that iron is the fourth most abundant element in the earth’s crust.

I don’t recall that we found anything useful to do with the magnetic “dirt” but sometimes it was associated with little pea-size pieces of soft red stone, similar to red chalk. It was the non-magnetic iron oxide hematite, Fe2O3. Those were great for painting indian war paint stripes on our faces and arms. I suppose the black magnetic stuff was magnetite, Fe3O4.

It was a long journey from my early iron-age to today. In a small way that story recapitulates a larger history. Iron ore isn’t worth much without heat. Learning how to use heat to manipulate the element is the key to obtaining useful metal and to eventually forming metal products.

My woodworking abilities improved a lot from the orange crate period, but I sure wish I can been drawn into the iron working sooner. Today most of my work is done hot and it’s a lot of fun.

Thursday, July 14, 2011

Unconscious Design




Every designer must settle on some methods of imagination which usually works for them. I have become comfortable with a method which relies a lot on my unconscious processes.

While writing this I came across this note which I wrote in 1997.

“I think most of us agree that there is something we call “the back of our mind.” If I can’t figure out how to do something or I can’t remember something I once knew I can rely on coming up with the answer if I pose the question clearly and relax and go confidently on to other things. When the answer has been prepared it will push out into consciousness. It is not a mysterious thing. It is how mind works.

I put a lot of trust in it. When an answer pops up it is pleasing to see how the process is so dependable. You say, “Sure but what you don’t remember is the times that noting ever came back up.” Perhaps. I just figure that those questions were determined to be unproductive and the unconscious trash-canned them for me. Thanks.”

I picked up two commission projects this week which will take some planning. Right away I made notes about the plans and did a little research. I set up folders to collect more material as it came in. Now with that much preliminary work done, I will move back to current work. I anticipate that periodically things will occur to me which will move these new designs along, Somehow that skeleton will flesh out and soon a satisfactory conclusion will appear.

Sometimes jobs come with a lot of instructions and specifications in which case it’s mostly a construction challenge. The opposite type , complete artistic license, job presents more of a design challenge. I usually enjoy both types. In the final analysis it’s just about solving the clients problem.

I’ll come back to the design theme from another angle later in “Making work tell a story.”

Wednesday, July 13, 2011

Fire in the Hole




I like to use solid rivets. Emphasizing the joinery sometimes seems to dress up a piece which may otherwise be rather plain. They are a traditional or classical element whose use goes back to the Bronze Age.

Their nearly universal use in blacksmith tongs illustrates their advantage in being easily removable permitting repair and modifications.

If you do an image search for a rivet hammer, handheld type, not the air power hammer type, you will get the typical light cross peen variety. I’ve got a couple and rarely use them for anything especially rivets. A ball peen works best for me, at least in forming a rounded head. A flatter face is better for flush rivets or flat, low profile, ones. Maybe that’s what the rivet hammer is good for. The light weight which favors quick high velocity blows does make sense.

I only recently learned that in store-bought rivets the formed end is called the factory end and the one I form by upsetting, bucking, is called the shop end. That makes sense too. The shop end is also called the buck tail which seems to take a little more imagination to make sense. I suppose the factory end is the head and the shop end is the tail formed by bucking.

When bucking the factory end is supported by a rivet set to keep it steady and to preserve the head radius. I make mine by heating a block of steel and hammering in a carbon steel ball part way or using the press to do that. Various radius impressions can be done in a single block or individually. Incidentally some people seem to call the tool a rivet snap.

For most rivets I cut the shaft so the material available for upsetting is about 1.5 to 2.0 times the shaft diameter.

I usually slightly over-drill the rivet hole or slightly oversize the diameter with a punch or drift.

The out of usual context of this title occurred to me as I was heating a tenon in the process of peening. The punched hole was intentionally slightly larger than the diameter of the tenon so assembly would be easy but a tight fit was the goal. Directing the torch flame down the hole heated the base of the tenon, or rivet, so the following top blows would upset the shank to pretty well fill the hole. The next heats are directed at the tip of the tenon so it will mushroom to cover the hole and capture the bar. This is a small detail but sometimes important.

Another detail to consider with tenons, or rivets, and their corresponding fit holes is to make them both out-of-round, in other words, oval. There is extra rotational stability with this shape. Of, course it requires making an oval drift to prepare the holes. I’ve mostly used this on small items like delicate feet on small trivets.

In the process of making a lot of botanical stems I use a lot of 40d and 60d common nails. I use a cold stock shear to cut off the heads and gripper section. This leaves a lot of flat head rivet material. Common nails are tough and soft - I’m guessing about 1010 carbon steel alloy and work nicely as rivets.

I’m in the process of reworking some old inexpensive tongs which I picked up years ago in flea markets to form some more useful ones. I’ll likely have to make all those larger rivets myself. Fortunately I have some old rivet headers which I also found back in my flea market wandering days.

Sunday, July 10, 2011

Nest Fiber Tales




A local artist told me about another artist who once strung colored yarn abound his yard. During the nesting season the birds helped themselves to the yarn and incorporated it into their nests. At the end of the season the artist collected some nests which had become colorful pieces of art.

When I was a child, Mother would put out short pieces of string for the birds to gather for nests. There was really no shortage of dead vines, twigs and stems. The string just provided another opportunity for us to observe the birds at work. In the winter the nests were easy to find and it was interesting to observe the choices the nest builder had made.

In recent years I have purposely hung fiber material which I have observed the birds, particularly the Carolina wrens and orioles, using. This little wren seems to prefer nesting close to human activity. Every year they nest on the porch of my shop and in, or just outside, the garage. Usually they will pick a natural cavity such as an old shoe, planter, carton, or bucket which has a 3” or greater opening as the starting point then they will gather a prodigious amount of long fibrous plant material to finish the nest mass.

When I tore down some dead and dried out morning glory vines or cut the old pampus grass the birds went after the debris. When we replaced an old cotton hammock I decided to use the residual rope material for nesting fiber and make hanging dispensers to contain it. I cut the old weather weakened rope to smithereens, actually about 6” lengths, and unraveled parts of the twisted cotton fiber cord and it is the bulk of the fiber I put out in dispensers ever since.

We have a north facing entrance step and walk which becomes ice covered and hazardous in some winters so we got some coir, coconut fiber, ice mats to walk on. One of them got damaged and frayed and the Carolina wrens benefitted. Later I tore up that damaged piece and in the following nesting season three large wads or it were hung and it all disappeared before the autumn.

The dispensers I made were all simple ironwork projects in several styles. I now use the one which is quickest to make. The bowl is formed as a 5/16” textured round rod coil which is then pulled out into a vortex somewhat reminescent of our Kansas twisters. I hang them from a limb with an extended S hook somewhat above head height.

They are an inexpensive little garden novelty and sell well. Yesterday a gallery emailed that a visitor had come in and bought them all so I guess I’ll be making more of those today.

Friday, July 8, 2011

Smart Hand - Dumb Hand




Some question came up and stimulated me to look up something about screw thread. In the process I recalled a couple of long forgotten things and learned a few new ones.

I recalled that someone once told me that the way the standard right-hand wood screw thread helix was designed assumed the screw driver would be held by a right-handed person and drive when turned clockwise. This was based on the knowledge that supination, clockwise rotation of the forearm, was more powerful than pronation, counter clockwise rotation of the forearm, in extension. Lefties were out of luck.

Probably nearly everyone learned “righty tighty, lefty loosey” at some time - clockwise to tighten, counter clockwise to loosen. Apparently this is also known as the right hand grip rule for screw threads.

The action of supination can be produced by the biceps, supinator and brachioradialis muscles. Wikipedia says the later is known as the “beer drinkers muscle.” Now there is a handy bit of knowledge.

Think about the everyday forging practice where we draw a taper. The teaching instructs us to strike a number of blows, two or three, then rotate 90º and strike the same number and repeat until the shape is achieved. The rotation process and equal application of force keeps the deformation of the metal from going too far in one direction.

Today I had a lot of little pieces, screw hooks, to make which required exactly that process. I paid close attention as I worked and noted that, depending on how i picked up the piece, I may start striking while holding the workpiece in full supination. No matter the starting position, after two blows the piece was rotated 90º to strike the next two blows. So there seemed to be theoretically four possible 90º sequences; full supination to neutral and back, neutral to full supination and back, neutral to full pronation and back and full pronation to neutral and back. Most commonly, however, I was working back and forth between about 45º supination and 45º pronation.

I recalled that someone told me to imagine that in this process the tong hand is the “smart hand” and the hammer hand is the “dumb Hand.” The tong hand is mostly responsible for putting the work piece in the correct position for the hammer to strike while the hammer hand is just bringing the hammer up and down in the same arc.

Well, there is more to it than that but as a teaching device it must have been worth something because I still recall it. I also recall Francis Whitaker saying, “If you can’t hold it, you can’t hit it.” This was a plea for choosing tongs which properly fit the work piece and allow it to be manipulated without slippage.

It takes time and practice to develop the motor skills associated with hammer on anvil forging. Repetition is key in learning hand control in this and many other activities.

There is a big difference between watching and doing. I think most casual watches do not appreciate the blacksmiths finesse with both hammer and tong control. They mostly are just aware of the rhythm of the hammer striking, bam, bam, bam and are unaware of the directional nature of the blows, use of top and bottom radius, changes in force associated with changes in the workpiece metal in a falling heat, etc. There is a lot of physics involved and both hands need to be “smart” but skilled is a better word.