The BAM Tent

We’re back home after a short working vacation. Once again working two days in the demonstration tent of the Blacksmiths Association of Missouri was a pleasant break in the routine and, as expected, I learned a thing or two.

The weather cooperated by bringing two very mild temperature days which are hard to come by in August. We were able to spend time with long-time friends, not so long-time friends and family. The main plan was to work on my offset tongs but, as usual, we wandered off on another project proposed by a visitor. It was entirely predictable that we would not have the stock or tools best suited to the job so work-arounds must be devised.

As a learning experience, the challenge was a success. As a functional object, the creation was a success. As an example of skilled craftsmanship, we came up a bit short. This all served to reinforce what I learned from a demonstrator several years ago and have come to think of as the “first law of demonstrating” - do what you already know how to do.

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Off to Join the Circus

Well, it hasn’t come to that yet, but tomorrow I am off to enjoy the Missouri State Fair in Sedalia, Missouri, and work/play in the Blacksmiths Association of Missouri demonstration tent. This annual event is a favorite part of my year; I'll be away from the blog for several days. When my father mustered out of the Army Air Corps in 1946 we settled in Sedalia. That was where I grew up from age 3 to 18.

We have dear friends in Sedalia who give us a place to nest and good food and conversation. Every visit has built more lovely memories and complement those which date back to elementary school and even preschool days in Sunday school.

When I was living there, State Fair week seemed to coincide with my birthday, August 27th. But school starts earlier in the calendar now. Part of my birthday present used to be passes to the races for me and several friends. We could count on hot weather, a drought-breaking rain and sometimes a severe storm. I could go on for quite a while with memories of The Fair.

In the days preceding our trip I must decide what to pack. I’ve pretty much given up on trying to construct a “crowd pleaser.” It’s a lot more like a reception line than a static audience so the vast majority of visitors see what they want to see in less than a minute. A few will linger to ask questions and the oddball, potential blacksmith, will hang around and try to learn something. Those few will be offered the possibility of joining BAM and opening the gateway to eternal happiness. Well, again, I may exaggerate.

Back to the packing issue. After quite a bit of experience with this sort of thing, I now pack what I will need to accomplish what I would be doing in the shop anyway. Off and on I work on improving my workspace. Recently I looked over the tong racks in the forge room and concluded there were about twenty pair which were used frequently and another fifty which may not have moved in the past few years.

I removed all of the archived ones, looked them over, and concluded that most could be converted to useable tools. Most were odd shapes, too heavy kludges which I picked up for about $5 apiece at flea markets in the early 90’s. I took out the rivets and prepared them for reforging.

Over the years I have become picky about tools and have firm preferences. In tongs I have a very specific style of offset tongs which I like. I acquired a set of about eight round stock tongs sized from about 1/4” to 1” in an eBay auction about 15 years ago. It may have been the best auction purchase I ever made. At the time I didn’t realize I had purchased anything as unique as it was. I have been to a lot of shops and studied all the tongs offered by the big suppliers and have never run across this style; however, as I pondered my “ideal” tongs, I felt these were not quite on the mark. I had come to like the feel of the ball finial on the reins of a couple of manufactures tongs and decided this feature should be added. Moreover, a ring could be superior to a ball as it could accommodate a hasp or link catch as an alternative to a tong clip when used in a specific production run.

Now, I had a Fair Week project. It is hard to find the time for a couple of days of experimentation. It feels like a luxury extravagance in the work week but can be excused during Fair Week. On Saturday my student assistant, Scott, came and we pounded out enough tong blanks to see me through.

I’ll post a detailed description of my method of making tongs later but this is an introduction. I use 3/8” x 3/4” hot rolled flat bar stock. The blank is 13” long for the average pair of tongs. A couple of inches shorter will make nice light weight tongs for 1/4” stock and a couple of inches longer will make suitable tongs for 1” stock.

In almost every project I try to enhance my convenience in the first heat. This may be, (1) add two plane volume, (2) draw length, or (3) add a convenience bend. If I have a blank and have added two plane volume (potato chip form) as the first step, I can easily pick it up off the floor with pick up tongs rather that chase it around flat when dropped. Drawing length first adds a handle. A convenience bend facilitates localizing the heat. This power to bend and unbend at will is one of the great aspects of blacksmithing.

In this case, I wanted to prepare my blanks so I could work at the fair in a casual manner with hammer on anvil doing the refined jaw work. I decided to do the reins drawing in the shop with my power hammers to save time, effort and perspiration. Each reins segment was drawn out to 3/8” round in two heats. This left a great handle which can be drawn to full length with at 5/16” stop later when I am back in the cool shop.

It could be pretty hot on those demonstration days and I believe in the slogan, “Never let them see you sweat.”

http://www.thisdayinquotes.com/2010/06/never-let-them-see-you-sweat-was.html

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Pipe or Tube?

When I started to build my shop and all the work supports, tables and other equipment I was mostly getting the steel from the scrap yard. I just picked up pipe and tube which was “about the right size.” It wasn’t until much later and working on commission jobs that I seriously studied pipe and tube characteristics.

As it turned out, I needed both in different circumstances. Pipe is a vessel which is designed to conduct a fluid. It is sized by inside diameter and the wall thickness varies in accordance with the pressure required to contain the fluid. All of that was essentially irrelevant to my needs.

Usually, what I needed was tube. Tube is considered a structural steel element and is sized by outside dimension. The wall thickness varies according to the structural load it will bear. In the sizes which I work with, tube is less expensive than the roughly equivalent size pipe.

I don’t have an engineering background so I came to blacksmithing lacking a lot knowledge which would have been very useful and which I acquired piecemeal and haphazardly along the way.

There is a lot more to consider when building with these materials including issues of threading, fitting, ASTM grade, seam or seamless and weight. Here are some references which may be useful.

Pipe vs Tube

http://www.engineeringtoolbox.com/pipes-tubes-d_347.html

Carbon Steel Pipe

http://www.pipemarkers.com/pipe-data.html

Structural Steel Specifications in PDF

http://www.saginawpipe.com/product_charts.htm

Pipe Weight Chart

http://www.davidstrasser.com/pipechart.htm

Tubular Steel PDFs

http://www.tubularsteel.com/products_welded.asp

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Wet Coal or Dry Coal?

It was a tedious weekend having to do house repairs and recycling, however, there is a sliver lining in those clouds. A break in the heat wave is what permitted me to get these chores done. It also allowed firing up the coal forge and doing some forging on a larger scale than the little torch projects I’ve been doing for most of the past month.

Today we worked three jobs. One required upsetting some 1” bar stock ends one required punching some pockets where lag screws will seat and the third involved bending some 3/4” round stock to 1” and 1.5” radius 180’s. All easy enough but much easier (and less expensive) with coal fire heat than torch heat and it was something of a relief to make this little progress.

As we were working with the dry coal fire it occurred to me that we hadn’t used a wet coal fire in quite a while. I probably only manage the fire about 20% of the time and mostly leave that task to my assistant. I recall that when I was first forging I used wet coal a lot. I learned about it at CRMS watching Francis Whitaker and his assistants. It does a better job of making a “cave fire” which is great for forge welding and it probably is more effeceint in keeping the fire in a more confined space thus conserving fuel.

Most of my work does not involve forge welding and the fuel is relatively cheap compared to labor time so that has encouraged a “work very hot and quick with multiple pieces” tactical approach. Today I tried to focus on what we were actually doing and characterize it better. It was essentially a method of keeping the fire as hot as possible all the time - frequently pushing coke into the hollow - and shifting the work pieces to keep their heat at the desired orange-yellow incandescent color. It requires constant attention to avoid burning up the work and it possibly uses more fuel than when running the fire temperature up and down but it is the practice to which I’ve become accostomed. In an hour and a half or two hours a large clinker will form but that is when I quit anyway so no time was wasted dealing with it.

Now that all these thoughts have come back to me I think it would be interesting to spend more time working with the wet coal again. Then I remember, “Never trouble trouble, until trouble troubles you.” This has evolved into our style fire management and it works for us. Alas, I’ve got a lot of other things to think about that seem more urgent.

Stopping By Woods on a Snowy Evening

Whose woods these are I think I know.

His house is in the village though;

He will not see me stopping here

To watch his woods fill up with snow.

My little horse must think it queer

To stop without a farmhouse near

Between the woods and frozen lake

The darkest evening of the year.

He gives his harness bells a shake

To ask if there is some mistake.

The only other sound's the sweep

Of easy wind and downy flake.

The woods are lovely, dark and deep.

But I have promises to keep,

And miles to go before I sleep,

And miles to go before I sleep.

Robert Frost

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Engine Valve Tools

I made two punch tools last week and each was dedicated to a small project. I’ve mentioned my affinity for making dedicated tools, jigs and templates which are stored as a group related to each repeated project. In these cases each punch had a round taper to make a 3/16” hole. I made each of them from one half of an engine valve shaft and welded a short utility handle.

I have used this valve stock for quite a while to make chasing tools and drifts and have been impressed how well they hold an edge and shape. I always thought there were some variety of stainless steel which was air hardening until I found the article below. I’ve never had to buy any as the auto mechanics seem to be quite free with giving used ones away.

I made one punch just by grinding on a zirconium sanding belt and the other by torch heating and forging the taper and then grinding to finish. I keep a batch of utility handles ready to use so making the punches and welding the handles took a total of about 5 minutes maybe ten if I count the time spent stamping the names on the handle labels. That seems like a good investment for tools which I anticipate will last for years.

Nice reference about engine valve alloys:

http://www.enginebuildermag.com/Article/2564/valve_alloyswhat_makes_them_so_special.aspx

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Too Hot To Forge

It’s been over 100º almost every day for about three weeks and 112º yesterday. I was about to say, “I wish it would let up”, but that would leave the opening for someone else to quip, “If wishes were horses then beggars would ride.”

In the past I had a rule that I wouldn’t forge on days when the temperature was predicted to reach 90º at 3 PM, the usual peak forging time. I’m far enough behind schedule this year that I’d be willing to raise that to 95 º but haven’t found one of those days recently.

It has been necessary to turn to other small jobs which can be done cold or with torch heat. At least it’s an opportunity to make the things I put in the Prairie PastTimes gallery. I only make a few items in the category of “Colonial Reproduction” or “Old Time Ironwork”. They aren’t big sellers on the Great Plains, so far removed from their main historical base. There are a few pieces like the sawtooth trammel, sticking tommy and the fat lamp in which I see a sort of primitive engineering elegance which appeals to me. This week it was time to make fat lamps.

I make one simple style with an open pear-shaped pan, rived to a vertical bracket which ends in a swivel made from a forged square nail attached to the hook/spike hanger. I works as poorly to produce light as any of the similar historical types. These crude, but portable, lighting devices, burning a tallow soaked wick, were first made of pottery and later bronze and iron and spanned a lot of history from the campfire to the oil lamp and candle.

As this is a project which is repeated and made in batches, it is heavily jigged. I first made a die set to use in the power hammer to forge the pan and later adapted it to the hydraulic forging press. That was the only fairly hard part to get perfected. Now I can deep draw the pan from either a 16 or 14 gauge mild steel blank which is heated in the coal fire to scale. The perimeter excess is trimmed away and I use the press once more to true the form then tumble. I touchmark the bottom of the pan and punch the rivet hole in the back of the pan directly opposite the wick trough.

The other components are not complicated but I’m not an expert when it comes to making square nails so that is more time consuming than it should be. I have found every part of the project to be easier to accomplish with torch heat except for the pan forming. Doing anything this repetitive can get boring for me so I work at it off and on between other design and test work. This week I managed to complete 18 lamps.

It doesn’t appear that the coming week will be any cooler. Maybe that will be sticking tommy week - anything to stay cool. I heard that a fellow saw a dog chasing a cat and they were both walking.

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Trust But Verify

I needed to make some coils for a project in which the coil would serve as a hinge eye. The barrel stock would be 3/8” round and the coil stock 1/2” round. So, I needed to calculate how much stock I needed to allow for three wraps. It’s not that I distrust math and this is rather elementary but I wanted to see how close this worked out in actual practice knowing “There’s many a slip twixt the cup and the lip.”

A 30” piece of 1/2” round stock was marked with a presto pen at the appropriate transitions and I put a center punch in the fly press and laid the round bar in a “v” block and punched a mark at each designated point. Using the torch to heat the bar I carefully pulled it snugly around a 3/8” mandrel for three complete revolutions in one segment and two revolutions in another. Then I inspected the punch marks. They proved the predicted and observed results were identical.

In another project I will wrap a 5/8” round tapered element around two pieces of 5/8” square. The match between prediction and observation will be less exact because there are more technical difficulties as well as more complicated math, but I’m confident I can get close enough.

Ronald Reagan was fond of using “trust, but verify”. It is a translation of a Russian proverb which, allegedly, was also often used by Lenin. This exercise is a way of demonstrating how taking a skeptical approach and working through it can build confidence.

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Flying Wire

When I made the move from doing woodworking to working with metal a lot of the tools were new to me. In the days before building an effective tumbler I used wire wheels to remove fire scale. I used wire wheels mounted on a bench grinder and wire cup brushes on an angle grinder.

It didn't take long to discover the annoying and dangerous tendency to shed wire strands which will penetrate clothing. I used heavy gloves and a full face shield in addition to safety glasses. Still that didn't save me when an angle grinder kicked back and the knot wire cup brush grabbed my tee shirt and plowed across the skin of my midsection. Not serious but scary and painful enough to get me going on designing a better tumbler.

An experienced blacksmith gave me the tip of using a variable speed polisher/sander instead of an angle grinder. I got an inexpensive one and it did work well. Most of the time my work doesn’t require high speed operation. The tool is pretty heavy and more awkward to use than an angle grinder. I use it infrequently so it has lasted ten years so far.

I was well acquainted with a wood router and had a speed control unit so I tried it on an angle grinder and found that setup works better. My work can be accomplished at speeds well below where wire breakage is likely and the velocity of a broken wire would not likely cause a serious injury.

This is the model I used.

http://www.harborfreight.com/router-speed-control-43060.html I notice it now sells for $19 but was $15 when I bought it.

I gave up the use of the wire wheels on the bench grinder altogether and never tried a speed control on it.

The tumbler has largely replaced the use of the cup brushes too but on the occasions when I need one I prefer the stainless steel knotted cup brushes.

Civilization owes a lot to the inventors of the wheel and the related beneficial applications of rotary motion but they also introduced the hazards associated with the kinetic energy of a rotating mass. It's our responsibility to utilize the benefits and subdue the dangers.

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