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Anvil Stand question


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I'm going to get a new anvil sometime in the near future, somewhere in the 200+ Lb range, and I've been thinking about the stand. A bunch of 4X4's all strapped together, like many guys have built, first came to mind. Then I started thinking about the stand as an extension of the anvil mass. To make a long thought process short, I was thinking of casting a column of reinforced concrete as the core element, surrounded by 4X4's. I'm thinking that this would would transfer the shock to the slab better than wood. 

Do you guys think that this idea is worth the trouble?

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Give some thought to the interface between the anvil and stand. Will there be, or develop in time, an air gap between the wood and the anvil (anvil now supported on the concrete) or an air gap between the concrete and the anvil (anvil now supported on the wood)?  If an air gap develops then the shorter length material has lost its effectiveness. Put a pad in the mix and it fills the air gap but does not improve the design.

Unless the floor is flat and in perfect contact with the stand it can wobble a bit. To get perfect contact you can use a 3 point contact system, but that raises the stand off the floor except in those 3 locations, and makes the stand to floor connection with an air gap under a lot of the stand.

If the stand weight adds to the mass of the anvil, then why do we have different weight anvils? For discussion let us take a 50 pound anvil and a 500 pound anvil. With the 500 pound anvil resting directly on the ground, we can construct a 450 pound stand for the 50 pound anvil and get the same mass in contact with the ground. Will it work the same? (This disregards the size differences of the anvil face, hardie holes, etc)  

Another way to say this is the anvil of YOUR choice (the one you use) is connected to the ground (earth) via the anvil stand (for convince and height). The earth about 13,170,000,000,000,000,000,000,000 pounds (or 5,974,000,000,000,000,000,000,000 kilograms). What is the most solid way to connect the two? One way would be to drive a large pier into SOLID bed rock, and then attach the anvil via a solid connection to that pier. Anything less than going into bedrock is a compromise (the stand resting on different types of dirt or material above the bedrock). Any type anvil stand is a compromise to a direct connection to bedrock via the pier. If you can not find bedrock, then pour a massive concrete base to substitute for the bedrock. For reference, the approximate weight of 1 cubic yard of concrete is only 4024 pounds

In the real world, we make compromises. (grin) 

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Thanks for your thoughtful response Glen. I was thinking that the anvil would rest right on the concrete, and be anchored in to the concrete. I would pour a column slightly larger than the footprint of the anvil. I would use the 4X4's as an outer form and pour the concrete right where the anvil will live, then level the top. This gives the concret very wide and solid contact with the slab. Then I would bolt the concrete to the slab. As you mentioned above, it all becomes one mass in terms of resisting the shock and force of a hammer blow (BTW, my garage slab sits on bedrock).

Wood, although it seems very stiff, still has some give, or spring to it. We pay good money to get an anvil which has a large mass and a very hard and unyielding surface, then mount it on wood (often with silicon in between). Doesn't make a lot of sense to me other than it may not really matter all that much anyway. 

 

Ted

 

 

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Good advice Glen, thanks. 

The concrete would be right under the Anvil, and I would put reinforcement in it. The compression rating for reinforced concrete is way beyond anything I could exert with a hammer on an anvil with large footprint. I guess it wouldn't hurt to put a steel plate under it for a wider load dispersion.

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I’m following your logic and I can see it’s merit but a concrete post surrounded on all sides by 4x4’s would create a rather large foot print. Although a large footprint is good for stability it would prevent you for getting up close to your anvil. Just something to consider. 

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It's been discussed before ad libitum. There is no practical way to make the ground part of the anvil mass. Two different materials with an interface do not become one as much as one would like them to. Small anvil on concrete pyramid and large anvil on same concrete pyramid perform like a small and a large anvil. 

The best anvil stand is a solid tripod made of thick wall rectangular hollow section at some 12 degree angle filled with sand and oil ... on a one or two inch plate with the anvil bolted down with big nice bolts. Super stable and solid and still moveable. Concrete does not do well with hammer blows and is immovable. 

The function of the stand is not to increase the anvil mass, something that it can not do, but to support the weight safely and if possible stop the pesky ringing. It is the anvil that absorbs the hammer blows not the stand. 

 

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10 hours ago, Marc1 said:

Two different materials with an interface do not become one as much as one would like them to.

That's an interesting thought, and one worthy of discussion. If I weld a 200 lb anvil to a 500 lb block of steel, instead of just resting it on top, will that change the characteristics of the anvil? If so, then at what point do they essentially become one mass? My point of reference on this question is whether all the pieces resonate at the same frequency. An anvil will ring because it is free to do so. The shock of the hammer deforms the anvil slightly, which then continues to deform at its resonant frequency until the energy is used up in heat. That energy was not used to deform the work. How can we recover that energy?

Attachment is the crux of the matter here. An anvil which is firmly attached to a solid base has different characteristics than one which is simply resting on the base. The base also improves once it is attached to the ground. With everything bolted down, bouncing, flexing and lateral movement are significantly reduced. The energy of the hammer blow then goes more into moving the work.

Cheers,

Ted

 

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The thoughts have been discussed a number of times here. It's an intuitive thought but a concrete stand is actually worse than wood. High compression strength is NOT impact strength. What you're referring to as the "energy of the hammer blow" compressing, etc. the anvil while true isn't very accurate. Compression waves = sound waves. resonance being the waves reflecting from opposite sides till they eventually stop. Concrete is strong in compression because it doesn't compress measurably and has virtually no rebound. Placed in contact with an anvil concrete pulverizes without improving anvil performance.

Marc 1 and I prefer a steel tripod though I haven't seen an improvement with a steel plate to bolt the anvil to, nor heard a lessening of ring by filling the legs with sand let alone sand and oil.

I don't know what the angle of the legs is on my stands but the more vertical the more rigid, the more rigid the better. 

The interface between my anvil and stand is a flange up angle iron rim the same size as the anvil foot. My hammer and tong racks wedge between rim and anvil foot to secure it. They (my anvils) don't move if the stand doesn't, Hammers and tongs are right THERE and they've taken the ring out of a Soderfors and a Trenton, both known for a deafening ring. 

Where effectiveness under the hammer is concerned both anvils are more effective on steel tripods than on wood blocks and I did use stacked lumber for a short time before getting a wooden block for the Sorderfors. The Trenton hasn't been on wood since I brought it home.

Brian Brazeal mounts his anvils on steel tripods with vertical legs. I don't know if he fills the legs with anything though.

Frosty The Lucky.

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To fully understand what's happening here we need to get down to the atomic level. A good analogy is a round rock being dropped into a swimming pool. As the rock hits the water it sends out a pressure (shock) wave in a roughly conical shape. This displaces the water for a short distance until the friction of the water slows the rock down. The energy from the rock hitting the water is stored up in the displaced water, which then reverses direction, filles the hole and causes a splash. The splash is important because it illustrates the return path of the energy.

When an anvil is struck with a hammer, the same thing happens. A conical shock wave radiates from the point of impact and displaces molecules of metal. These molecules then force the ones right behind them to move and on and on. Eventually the wave gets to the bottom of the anvil and displaces those molecules in the direction of the wave. This causes a bulge in the middle of the anvil which actually bends the ends of the anvil up. The distances are minute but significant. Once the shock wave passes, the ends of the anvil spring back and overshoot, which sets up an oscillation. This is the ringing you hear.

We'll next look at a 50 ton block of hardened steel. We hit it with a hammer and all the same things happen except it doesn't distort. Nevertheless, molecules were displaced around the point of impact and almost immediately return to their original position and, having mass, overshoot. The pressure wave is now perfectly reversed and is focussed on the point of impact. The "splash' is a slight upwelling of the steel and the energy goes back into distorting the work as the hammer comes to a stop.

This is why heavy anvils perform better than lighter anvils. They distort less and return more energy to the work. 

Bolting your anvil down to the stand makes it quieter, which means it isn't distorting as much and wasting energy. Bolting down your stand does the same thing.

Wood is a good shock absorber, steel and concrete not as much. 

If I decide to build a concrete base, I will run thick rebar vertically from top to bottom to bare the shock load. The concrete will keep it from distorting. 

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If you need a portable anvil you cant beat a metal stand.  Ask any farrier who sets up 6-8 times a day.

If your setup is permanent, you just cant beat a stump buried a few feet in the ground and the anvil set into the stump on a bed of fine sand.

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Metal stands are good and so are stumps. I have nothing against anything that works for you. 

I'm going to be spending a fair piece of change on a new anvil and I want to get the optimal performance it can provide. Getting a solid grasp on what enables that is my goal here.

I have done numerous experiments with machines I have designed and built, and the biggest obstacle I had was overcoming parasitic oscillations. A ringing anvil is a good example of a parasitic oscillation. These oscillations rob energy from the system. I have never had any trouble with reinforced concrete oscillating. 

Contrary to many opinions, reinforced concrete has very good shock resistance when the load is distributed properly. Huge power hammers are set on concrete and you don't see the pad cracking to pieces. Concrete piers are driven by pile drivers deep into the ground without shattering. How many of the concrete floors under an anvil have crumbled due to the anvil usage? 

The base of the anvil disperses the shock load over a wide area, rendering the argument mute, especially if the anvil is bolted down to the concrete. 

My anvil is going to be set up as a semi permanent piece of equipment in the shop and will not be moved. I want the stand to be as heavy and stiff as I can make it. That doesn't work for everyone, but it does for me. 

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It is all good and proper to elaborate on the physics of collisions just for the fun of it. Done it myself a few times.

However when it comes to the simple matters of an anvil a hammer and a bit of hot iron, things take a different meaning. 

How many times have your heard about the rebound and how important it is because it returns energy into the work? 

Well I have news for you, it does not, for the simple reason that you are not hitting the anvil but you hopefully will be hitting hot iron that is plastic and will take most of the force of your hammer blow like the tires of your car when hitting a bump. 

What you want is a good quality anvil just so that you don't deform it and don't chip it's edges. 

And another thing you want is a good size anvil so that the remaining energy of your hammer, the one that is not absorbed by the plastic hot iron, does not rock the anvil annoying you no end. I cringe watching those YouTube videos with expert blacksmith and their wandering anvils and vices ... oh my ... can't watch it. 

There is not much more to it, despite what folks would like to make it. The super high performing stand is a waste of time. Get a good size anvil proportionate to what you are working on, bolt it down so that it does not ring nor move. If on a cast iron stand 1000 lb heavy or suspended from strings up in the air, makes little difference.

Yes I said it and so did Frosty ... apparently we do agree on something, what do you know? :) ... tripod wins hands down. Sand and oil filled is not to increase 'performance' but to stop the stand from ringing. Hollow steel pipes ring like a church bell. 

But a stand is a stand, meant to hold the anvil up and stop it from tipping over. That is why tripods have legs at a certain angle. Read somewhere that 9 is minimum and 18 max ... (?) maybe maybe not. Straight is certainly a tipping hazard and 20 degree may be too much.  If an anvil ever fell on you you would know that it is not fun at all. 

I take an oversize anvil pooreley anchored to a smaller one bolted to the center of the earth anytime. 

Oh ... and to stop a tripod from tipping, I have a nice trick. A piece of steel cable hooked under the tripod, a hook into the concrete and a turnbuckle to tighten it up. If you decide to move your anvil, all you need is another little hole in the concrete and another anchoring hook. Beats bolting the tripod with 3 or 6 or even 12 bolts like I have seen people do. 

If you have dirt floor ... well that is another discussion for another day. :)

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There are a number of diagrams put out by the manufacturers of huge power hammers historically showing them being set on layers of large oak balks before they set on concrete,  are these incorrect?  It was the standard method for over 100 years... If so when did they change to direct to concrete?

 

There is a classic case of "diminishing returns" with anvils and hammering.  Yes you can eke more performance out of them; but after a while the weight of the anvil pushes such gains to the outer parts of the bell curve.  I believe that most methods of quieting an anvil would not improve rebound as they are just damping the resonance and not putting the energy back into the system.

eg: My 469 pound Fisher is not fastened down to it's stump as it's inertia resists my puny hammer blow quite well enough for my work.  I did put a couple of fence staples around the base as I noticed it creeping under heavy sledging---I didn't want it to make a break for the edge of the stump trying to escape.

 

 

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Thanks guys for interjecting a little common sense into the discussion. I do tend to overthink things, but I find it interesting nonetheless. I live in my head a lot.

8 hours ago, Marc1 said:

I cringe watching those YouTube videos with expert blacksmith and their wandering anvils and vices ... oh my ... can't watch it. 

LOL, I've watched a few of those myself and feel the same way. 

I like your idea of the cable holding the stand down. 

I realize that a lot of this is not highly relevant in the practical world, especially if you have one of those giant anvils that a small plane could land on. 

Nevertheless, overthinking has served me time and again in the past. It allows one to arrive at a better perspective on what is reasonable and what is overkill. It also stirs up new ideas.

I really do appreciate the support and feedback this community has provided. Thank you all. 

 

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I know this is fun your you Ted but there are people reading this forum who don't realize you're brainstorming ideas and we have to address your misconceptions to keep others from making those mistakes. 

For instance. Where on Earth does anybody drive concrete piles? I spent 20 of my 30 years working for the state of Ak DOT AND PF, Headquarters Materials, geology section, Bridges and Foundations. I was an exploration driller but spent a lot of time discussing issues regarding the mechanics of bridge foundations with the people designing them. 

When you see concrete bridge piers they were built by driving STEEL piles, usually H piles but often can piles or rarely sheet piles. Which are then formed up or baled out the concrete poured and finished.

However, I do admit I haven't been around the HQ or Design guys for about 20 years and things change. Please post a link to information regarding driven concrete piles. I'll happily admit my knowledge is outdated, I can be convinced if you can provide legitimate evidence. 

Planet earth is mostly soft and squishy so it's not such a good base on an atomic level. Nickle iron asteroid maybe; the moon? 

Frosty The Lucky.

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