anvil weight addition

[Drew]

Ok, so I have a 90 kg anvil and a big block of mild steel about 3x10x20 inches... I would guess it's a hair over 100 lbs just from how it feels to pick up. I was wondering if there were a way to really securely attach the anvil to the steel block in such a way that it would functionally help the anvils stability. Granted, forge welding is out of the question. I'd prefer not to try and weld the anvil at all.
So... caulk, JB Weld, epoxies... etc.
Would this do what I think it would? Would it just make the thing harder to move and not really help its stability much?

[jayco]

Welcome to IForgeiron, Drew!
Here's an idea I've thinking about for some time, since I have a 109 lb. anvil on an oak stump. (This would work with any London pattern or similar anvil)
Back in my logging days we used fairly large log chains and binders to hold loads of many tons in place on trucks. With a large enough binder and a 'cheater' pipe, it's possible to crush the outer fibers in green oak logs.........that's pressure.

Over the years, I've tried bent over nails, lag bolts, and other things to hold anvils securely in place. These things work for a while, then begin to work loose, allowing my little anvil to bounce around.......which, of course, causes my hammering to not have the impact it should.

Anyway, my idea is to put a large spike near the bottom of the stump(front and back),
place a log chain 'necklace' around the waist of the anvil, and use the binder to hold everything tight. And if I want to move the anvil, or reposition it, all I have to do is loosen the handle. Should work.

James

[Glenn]

If you put the anvil on the block you do not get the added weight value. If this were so, everyone would buy a 50 pound anvil and put it on a 450 pound anvil stand in order to have a 500 pound anvil.

[Drew]

Well, Jayco... that sounds like just a fine idea. I myself tried really heavy lag bolts and chain, and found that eventually the lag bolts would start tearing up the wood in the stump just enough to loosen up and eventually to strip out too much to keep clamping it down. Too bad, as I thought I had finally come up with something bullet proof. I haven't entirely given up on the idea, though I may give up on the stump itself.
Glenn... this would be a fabulous time to talk about or have some links to information about how anvil effectiveness works. It's all just a bit confusing, and to be honest one of the first ideas I had when I wanted to buy an anvil (the block of mild steel I have now WAS my anvil at the time) was to get a little 70lb farrier anvil and do just what you're talking about.
The variables are a little complicated, but I eventually gathered enough info to know that I would need an anvil big enough to essentially act on its own and that the "base" and the "anvil" could never have their masses combined in such a way that the rebound and ultimately forging efficacy of the anvil would increase as though it were simply a larger anvil.
I guess what I'm asking about here is simply... now that I have an anvil that, by itself, is big enough (if such a thing exists) to do what I need it to do... how do I begin to really get the base it sits on right. My thought with gluing it to a large plate was simply to give it a heavy, broad, and flat "foot" to sit on. What I would mainly be hoping to accomplish was to keep the anvil from jumping so much when I work on the horns, and perhaps to shut the anvils ring up a bit. Aside from that, having a large flat surface would make the thing much easier to bolt down to whatever I use for the rest of the base/stand. I'm thinking, I suppose, of something like the feet on a hofi anvil... which looks to me like a 200 lb anvil with some big, low, heavy feet. Granted, this may not improve the hammer rebound, but it sure seems like it would stop some of the jumping and hopping that even heavy anvils like to do.
Then again, I certainly do wish someone would make a 500 + lb. anvil that didn't have such a huge face on it. I work sitting down, so much longer than the one I have (branco bulgarian) would be a bit of a pain for me.

[Drew]

that was a bit long winded. However, I will say that regardless of what I do here, a discussion/explanation of how anvil weight is important would probably help a lot of people starting out.
Things like... why is mass important? Why can't you take a 10 lb anvil and just bolt it to something immoble? Why would a post anvil cause a more inelastic collision than a london pattern of the same mass? Why are farrier anvils too "springy" for heavy smithing?
In other words, there do seem to be a lot of misconceptions (including my own) about where the mass should be and why... and I know a lot of folks are busy trying to figure out how to get a smaller amount of anvil to perform like more.

[Drew]

here's how I understand this. Correct me if I'm wrong! Cause I probably am!
A perfect anvil will not budge even a bit when impacted with the heaviest force it will ever see, and will elastically rebound the hammer with perfect efficiency. Secondary considerations are resistance to deformation, usable shape, and simply being able to produce, move, and afford it.
1) The first consideration is simply the way masses affect each other, based on inertia, in a collision. We're thinking here essentially of spheres of an unknown material colliding in space. It's about conservation of momentum. Two equal masses will split the difference of their collision roughly 50 50... think of pool balls. The more mass one object has, the less it will be deflected and, because of the conservation of momentum, the OTHER mass will have to "take up the slack" and be deflected more. An ideal anvil would have infinite mass, and as such remain completely immobile while the hammer bounced back at exactly the same velocity that it had on impact. In the real world, there is a practical limit of efficiency here that's, I think, about 97-98%... stupid friction. Over on anvil fire it had been mentioned that only considering mass, a 50/1 anvil to hammer ratio was a good "point of diminishing return." In other words, much past this ratio and you stand to gain imperceptibly little return... a good stopping point considering that you will have to pay for and move the anvil.
2) Shape... this one is still in space, however... now the anvil has to have a useful shape. The variable here is rotation... that is, the rotational inertia and leverage forces that act on an anvil that is NOT a perfect sphere. In normal work, you typically are exerting force on the anvil that will NOT pass straight through it's center of balance and consequently exerts forces to TWIST the anvil. The closer to the central axis you are, the less leverage you exert to twist it. Also, the more mass an anvil has as a whole, the more inertia it will have in rotation. This means, essentially, that the more "blockey" and "compact" the mass is (drawn in towards its center of balance), the less an anvil will be able to be rotated by the hammer. In diminishing order... sphere, block, nimba anvil, farrier anvil, long rod, sheet of plate.
3) Elasticity... now we have objects made of a material... steel. Steel is, in this context, best visualized as rubber. It's bouncy, ringy, it vibrates and shimmies. This is both your friend and enemy as far as effectiveness goes. On the one hand, it has the capacity to "bounce" energy back from itself in a way that something more inert, like a big block of granite, does not. This is also why clamping an anvil down to something so tight that it ceases to ring or vibrate will also negatively effect rebound... it's "springiness" has been dampened. The more steel there is directly under a hammer blow... the more steel there is inside the roughly cone shaped cross section of the impact force as it moves like a shock-wave through the steel, the more this springiness will work. Moreover, these "shock waves" do not effectively conduct through a change of material or a bond that isn't essentially seamless and molecular... this is why sticking a little anvil super securely onto a heavy, even steel, base doesn't help hammering efficiency. Anything bond that would affect the "resonance" of the anvil will not transmit energy in a way that will effectively combine the two masses. So, imagine how useless 200 lbs of 1/8th inch plate would be as a work surface... which brings us to the "tuning fork" problem. Because of steel's elasticity, if an anvil has parts that are spread out and unsupported (imagine a long, 1/2" diameter steel rod), they will dissipate and absorb impact energy in the form of a useless vibration... that of a tuning fork. Again, we're back to blocky anvils being better for this... and this is why the skinny cross sections of nearly every part of a farrier anvil (designed for a high work surface/mass ratio) will NOT be as effective in returning/maximizing hammer force as a much blockier nimba/sawyer/post type anvil.
What do ya'll think... is this long-winded non-sense a good start for talking about this?

[yesteryearforge]

BIGGER is BETTER

[Drew]

couldn't agree with you more... bigger solves most all problems. However, how much did that awfully huge refflinghaus of yours cost? :::shudders:::

[unkle spike]

I guess I will be "odd man out" here. How big of face do you actually USE on an anvil. Other than the occasional laying of something lengthwise to straighten it, what good is a HUGE anvil face? I have a 110 ASO secured to a 14 x 14 pine block. I took some hardened pins I had, flattened and bent the end 3/4" slightly, drilled the block about 3 inches, and drove 6 inch "pins" in. Never moves on me. The pins are probably 7/6 thick or so, and I used on on each corner. My 2 cents worth.

[Sabre]

ya bigger is awlys better