Two Shop Built Air Hammers Described

Bramble Bush Editor: Chris Ray

Described below are some informative facts and a few modifications to the basic plans that were originally drawn up by Ron Kinyon. Plans for the "Simple Air Hammer" are published by the Artist-Blacksmiths' Association of North America. For those interested in building their own hammers, it is suggested that these plans be obtained as a primary guide, and any modifications that are made are done at your own discretion. ArtMetal is not affiliated in any way with the publisher or designer, nor is this machine endorsed by ArtMetal. Since this is a machine capable of serious work, serious consideration must be given to every aspect of the construction and use of this device for safety reasons.

Although the descriptive material written below may be construed as being a little bit off center, by no means is any of the technical information lightly dealt with. The two hammers described have been built and are currently being used in professional shops. These machines perform extremely well and are an economical alternative to the high cost of manufactured pneumatic hammers. The following is for information purposes only and is not to be considered a guide for the construction or use of these machines. ed.

The Saga Begins:

The hot midafternoon sun finally peeked out from behind the clouds, dispelling its shyness and bestowing a broad smile on the scene below.

From above can be seen a long road ribbon stretching out to the horizon. Moving along this road at a reasonable clip, is a ruby red pickup truck spewing out clouds of dust like mussed-up hair. The truck swings off the main road and slides to a gliding stop over the graveled driveway, its visibility momentarily shrouded by the dust catching up.

Bill leans over the bench and stretches his neck to look out of the shop window. He recognizes the pickup and steps around to the doorway of the shop, slaps down a cow-lick of hair and steps outside. He hesitates for a moment then waves to his unseen guest.

The door of the cab slowly opens and a pair of long, silky, tanned legs slither out, followed by the tall, lean and sensuous body of Phyllis Broadhart. Her gold lamé shorts look like they were cast over her body revealing every curvaceous contour both fore and aft. Her halter, a skimpy wisp of gauzy netting, barely caress her torso, suggesting an authenticity to her feminine bearing. Phyllis Broadhart stands tall and regal in her patent leather, spike heels and purrs, "Why hello Bill. So glad I could make it over this afternoon. I'm so excited that you invited me over so that I can show you mine and you can show me yours!"

Bill swallows an enormous lump in his throat with a resounding gulp. "Yep, glad you could make it Phyllis. I been wantin' to show you mine ever since I got it all painted in racing green and spiffied up. This baby really reciprocates like you wouldn't believe and the thrust of the strokes will make you sit up and take notice."

"Oh Billy, are you just being a tease, leading me on that way? Sometimes you're just too much for me." she giggles, covering her giddy smile with her long slender fingers. She shakes her hair as women sometimes do, then walks around to the bed of the pickup. The tailgate slams open and she lithely jumps aboard and begins to untie the rope bindings holding a rusty and oil-covered machine.

Bill rushes up to give her a hand. "Here, let me do that Phyllis. I can help with that." He feels a gentle push against his chest and hears her say softly, "No need for that Billy, I can do this. You wouldn't be wanting to get your hands all gritty. Now run off and get me a hand truck if you will, and I'll just bring this baby inside." She walks the air hammer to the edge of the truckbed, tilts it and then lets it slide softly onto the ground. A small puff of dust escapes from underneath the floor plate and her feet as she lightly jumps off and onto the ground.

Bill returns with a tubular metal handtruck and sets it beside the hammer. "No, no, that will never do, go back and get me the bigger one in the back. This thing is about five hundred pounds, and how is that puny thing going to carry it?"

"Oh, you're right, I didn't realize you were moving around that kind of weight."

"Oh, and Billy, would you also bring me a nail file, I think I chipped a nail."

"Okay," he says as he scurries off into the shop.

He returns with the heavy duty handtruck and stands aside as Phyllis mounts her power hammer into place and wheels it into the shop. "Is it okay to put it here?" she asks. "Sure, that's fine where it is. Now I'll get the air hose and we'll hook'er I mean connect it up." Phyllis picks up a rag off the bench and proceeds to wipe down the machine,oiling the ways, then fussing with a little of this and a little of that before it's ready to run.

The two friends stand off to the side, each admiring the fruits of their individual labor, and then they fire up the forge. "Well yours looks a little different than mine." observes Bill, head cocked to one side wondering if hers will work at all.

"Oh, I see you're giving mine a critical look Billy, hee hee, you're embarrassing me with that look on your face."

"Oh, I was just wonderin' why ya didn't paint it and all. It looks like a piece of crud with that layer of rust and the oil stains an' all."

"Don't let that fool you, dearie. I like it raw-looking, and it works like a charm. The guides are as smooth as a baby's butt, and it speaks with authority when it hammers away. You'll see."

Bill turns away and thinks to himself, "Well, I like mine better. But why didn't she at least paint it?"

"Yours is beautiful with that nice racing green paint and all, and I see that you essentially followed the original plans, more or less." observes Phyllis.

"Yeah, to keep it simple and all, I stayed as close to the overall dimensions of the Kinyon plans as possible. Having never done anything like this before, I needed a no-brainer approach. Besides, Ron does call this design a 'Simple Air Hammer,' and he already did a great job designing it."

"That makes sense when you are attempting to build something unfamiliar like this. You're a very wise man Billy, and sensible too. I find that sexy in a man." Bill runs his fingers around his collar thinking that he must have turned the forge up too high or something. Why else would he be sweating like this?

"I see that you made up a different design, Phyllis. How come you changed it?"

"Oh, it's essentially the same as the original plans except for the column and cylinder plate. Um, I guess the guides are different as well, and yes, the die plate is slightly modified, and maybe the anvil is different. But it's still basically the same as yours, only built as a sculpting tool rather than a production machine."

"But you can do the same on yours as on mine, right?"

"Oh sure, the differences are only minor," corrects Phyllis. "I simply used whatever heavy stock I had on hand in the studio, and it just happened to work out perfectly for my purposes. Did you have to get that ten inch square column from the mill?"

"Yeah, it's a 3/8" wall square tube, and it has a lot of mass to hold everything just right. I see you used a narrow but heavy duty I-beam for yours and then what looks like a half inch wall special channel for the guide backing."

"Yes, well I wanted to bring the guides out from the column just a little bit so I could have a six-inch throat clearance from the center of the dies. Because the column is narrow, I have a lot of clearance to swing the iron in a large arc for special applications. It looks like your guide post mount is about ten inches or so, giving you a deeper throat for your work. Very nice."

Bill stoops over and makes an observation. "I see that the floor plates on both of our machines are similar, about a one-inch solid plate about 24" x 36" which is heavy enough not to warp while welding the column on it. Four holes near the corners to anchor into the floor. Yep, we're pretty close on that, I'd say."

"Yes," notes Phyllis, "that gives our machines a smaller footprint on the floor, yet is large enough to mount our anvil bases and column into a compact unit. That's what I like about our machines Billy, they're not taking up a whole lot of unnecessary floor space."

Bill picks up a push broom and sweeps up some of the litter around each of the machines. "What really impresses me about these hammers is you don't need any special footings in the ground or nuthin'. Just bolt 'em to the floor and that's it."

"Yeah, I couldn't get over that, either. It makes it a simple matter to relocate the hammer when you have a special job or something and need the machine elsewhere. I was so pleased that I didn't have to dig out a foundation before hand and make sure I had just the right location near the forge. I simply tested the hammer here and there until I found the perfect placement then bolted it down."

Bill replaces the broom and turns to face her.

"Come here a minute, Billy, and let me fix that," coos Phyllis, as she reaches over and tucks the front of his shirtail back into his pants. "You're so messy sometimes!" Bill jerked back in surprise and hoped she didn't notice the extracurricular movement a little further down.

"Well, what do you say we stick a little something into the fire and give it a smack?" said Phyllis slyly.

"You mean here? Right now? Ummm... shouldn't know...I mean..."

"Oh you silly man! Not that! I mean that bar of iron over there. Lets get it hot and hit it hard!"

"Oh sure, that's what I thought you meant....of course," he says and proceeds to bank up the fire and lay the iron in the coals.

They turn both machines on and listen to the quick-tempered squishing sounds of each as the tups quiver, poised for action.

"I didn't put a muffler on mine 'cause it would slow the machine down. Yours is quieter than mine, but I don't see no muffler on it." observes Bill. "I did try a muffler, and you're right; it does slow down the machine. So I put this long hose on the exhaust port of the four-way valve, and it cuts out a lot of the high-frequency sounds without affecting the speed. Also, you'll notice that I now have a constant supply of exhaust air readily available while working, to blow off the scale accumulating around the work and dies."

"Hot damn, Phyllis, what a neat idea! I'll try it on mine later."

Phyllis steps over to the portable stand which holds an auxiliary air gauge and adjusts the pressure.

"How come you have that thing near the hammer?" asks Bill, "the pressure is already set near the compressor."

"Well, you may not have been aware of it, but you can fine tune the power of the hammer strokes with this thing in line. Since my hammer is used in a broad variety of ranges, I can modify the blows from full power at 120 pounds of pressure down to a finishing stroke using as little as 65 pounds. It's like having a 25-pound and a 65-pound hammer combined into a single machine. When I use the 35-pound ram, then I have a similar downward range with that as well, for lightweight and delicate work."

"I see," says Bill. "So you mean that after initially drawing down a piece, all you need to do is lean over and open up the gauge nearby and continue the finishing strokes on the surface of the metal while it's still hot enough to work on?"

"Precisely, or at least have it adjusted for the following heat. It's a simple way to vary your strokes in addition to the use of the foot controller to give you an extreme and ultra sensitive range of power. Also, I'm using a standard Arco foot pedal, not the ball valve pedal you built from Ron's plan. You seem to have a wider range of control with your valve; mine seems to have a sweet spot for it's more limited range, so this is how I compensate."

"Very clever, and I guess you like the feel of that pedal better than mine, so the trade off is an acceptable alternative."

"Oh, I just love it when you talk dirty," replies Phyllis.

"Okay, Phyllis, the iron is hot enough now. Do you want to run it through your hammer first?"

"Okay, Bill, but first I'd better put these on. You already know how much ear damage can occur if we aren't wearing our ear protectors."

"Oh yeah, you're so right about that, I wear'em all the time, no matter what."

"Even to bed?" mused Phyllis. "That could be so kinky, Bill."
Phyllis adjusts her iridescent blue-and-magenta-colored protective muffs designed by Stefan of Norway, dons the pair of safety glasses designed by Alberto of Milan and picks up the hot-tipped iron from the forge. She plants her lovely body into a stance and proceeds to first draw down the end of the bar. Bill feels the floor rumble beneath him as he watches her manipulate the bar first into a flat, spread it out on both sides and then pull out the very end into a nicely shaped radius. She pulls up the shut off valve to conserve the air in the compressor and puts the bar aside for Bill to look at.

"I was watching you do that, Phyllis, and I'm surprised at the way you can shape the metal in all three directions the way you did."

"That's because of this unique die I designed for the hammer. If you'll notice Bill, the top and bottom dies are shaped like a flat egg. The center has a flat for cleaning up the marks, and the radiused sides, front and back, act as a kind of fuller. It's a little different in that it sort of pinches the metal so you can shape it in different ways. It's not quite the same as a ball die but it looks like a compact loaf of homemade bread made in a pan."

Bill leans over to examine the die more closely."Oh, now I see. How ingenious of you!"

"No, not really, Bill. I got the idea because that is what I thought I saw on a Kuhn hammer once, but I was mistaken at the time. When I took a closer look, I saw it was simply the reflecting indoor light that gave the flat die that effect. Later, I thought about what I had imagined and realized that indeed it was a terrific die shape, so I made up a couple of sets. In fact, I use these dies for at least 60% of the general work that I now do."

"Well, if I don't learn anything else today, this alone has made our get -together very fruitful."

"If that's all it takes to satisfy you, darlin', the rest of the day is going to be a real piece of cake, if you know what I mean."

"Yeah, I know what you mean," Bill boasted, jamming his thumbs into his belt, hitching up his pants, then hesitated . "Uh....what do you mean?"

"Never you mind, you bad, bad boy. I know what you're thinking."

Phyllis walks over and puts another bar of iron into the forge. "It's your turn to show me yours Bill'ums, so tell me more about your hammer. I see that you've used the 2" cylinder with a 10" stroke and the four-way valves that are basically described in the plans. The ram looks like a four inch solid square by what looks to be 10 inches long."

"You got a good eye for this sort of thing don'tcha Phyllis?"

Bill swaggers up to his hammer and leans against it. "Well let me tell you about the anvil then, 'cause I'm real proud of that part."

"Please do," chirps Phyllis, "it looks so pretty sitting there all nice and curved and round looking."

"Yup, it was the center of a railroad axel -- about 300 pounds -- and it's perfect for the job. I was lucky to find a six-sided flange that slipped over the anvil perfectly. It already had six holes drilled in it ready for mounting. All I hadda do was lay out where the holes should be drilled and tapped into the base plate, then I welded it to the anvil and ta daa! instant anvil. I made a similar standoff as the Kinyon plans to secure it to the hammer column."

Phyllis nods in appreciation. "So how did you align all the parts for the construction phase of building?"

Bill clears his throat and answers, "I aligned the parts simply with a square and level. Checked all measurements twice and welded once. I didn't use stick welding as Ron had recommended, but rather preheated the metal to about 250 degrees and and made multiple passes with the mig welder at a pretty high heat for penetration."

"I see," says Phyllis. So by preheating that high, you were able to compensate for the apparent shortcomings of mig welding for structural work?"

"Yep. What did you do on yours?" he asked.

"Well, I'm still skeptical about the mig welds, so I used a low hydrogen 7018 rod and arc welded everything that needed to be welded. I've always trusted that method over any other for this kind of work."

"I see that the iron's hot so let me have a go at it ,and I'll show you what my beast can do" he grinned as he pulled the hot iron out of the fire and moved into position in front of his hammer. The thumping of the ram drew down the iron very quickly, and Bill expertly drew out a finished taper on his piece."

"Whew! That was fast!" exclaims Phyllis. "Oh sure it is," replies Bill. "This thing is banging away at 240 strokes per minute, about twice as fast as yours."

"Yes, it is very fast and efficient, but we are using our hammers for different kinds of work," says Phyllis.

"I have a 1/2 -inch air line connected to everything on my hammer" says Bill, "and I noticed that you connected a 3/8-inch air line on yours. Maybe you made a mistake."

"No, it's not really a mistake, Bill. For my work, I want a slower, more deliberate action for shaping the metal the way I do. However, whenever I want to speed it up, it's a simple matter of changing over to a half inch line. About an hour or two of work, no big deal."

"I see, so we have yet another way to modify the character of our hammers. Wow, custom deluxe stuff, wouldn't you say?"

"It sure is, and the way some people have laughed at our puny looking hammers because they think the humongous ones are the cat's meow. They don't know the meaning of meow. These modest -looking machines put out more than appearances would lead one to believe."

"Yeah, you can say that again. I wasn't convinced until I built mine, now you couldn't take this away from me if you offered me...uh... two Kuhn hammers...well maybe for two. ...I can always build another good one for myself again."

"Sure Bill, you could always do that. In fact it doesn't require advanced machining or fabricating skills wouldn't you say?"

"You're right, I was nervous at first because my experience is in blacksmithing not fabricating, and this thing gave me no problems at all to build. But you did some machining on yours, Phyllis, didn't you?"

"I did Bill, but it was simple refinement here and there, and not really necessary in order to build a good hammer."

Phyllis leans over for a closer look at the details of Bill's hammer. "I see you've made up the dies the way Ron suggested, using four bolts to secure each set."

"Yeah, it seems to be pretty secure and it's easy to make up my own set of dies for this thing. I notice that you have only two bolts holding each set of top and bottom dies on your hammer. Why'd you do it that way?"

"Well Bill," she says as she walks over to her hammer and picks up an air ratchet wrench. "With this air ratchet and using socket bolts, I can change each set of dies very quickly while the iron is in the fire for another heat. This way I can take advantage of the variety of dies I've made up for all kinds of variations while hammering out a single bar of iron. For doing the pieces for a sculptured piece, I can quickly change over from a fullering die to a texturing die, and the two bolt system works out very well."
"Yeah," wonders Bill, "but don't they come loose or anything?"

"No they don't. It really isn't necessary to have more than the two bolts for these dies, but they are narrower than yours and I guess that's why."

"Okay, I can see why now. My die plate is about four inches square, and yours seems to be about two inches by about five inches. Also your ram is four inches by six inches by 10 inches, so you can fit the longer die plate on it."

"Yes that's right, so my actual die sizes are generally two inches wide by about three inches long and shaped according to my needs. Of course with the special anvil plate, I also have other larger die sizes made up for certain applications."

"Well I guess that more or less covers it, don'tcha think?" suggests Bill. "How about we take a break from all this, and we can go into the other room and I'll show you my etchings."

The conversation of the two diminishes as they walk across the shop floor and enter another doorway. Phyllis' softly-murmured reply can be heard as she turns to Bill, "Why Billy, I just happen to have brought some of mine to show as well. They're in the truck, shall I get them?"


Contributors - Bill Roberts -
Phyllis Broadhart -

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Bramble Bush Editor: Chris Ray
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Last Updated: Sun, Sep 29, 1996