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Why mount anvils on things that bounce?


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So, I am preparing to begin hitting metal. I am starting to target and acquire tools. I have noticed that anvils are  often mounted on the end grain of stacked  planks.  This seems to me to encourage bouncing.  The mechanical properties of wood in this direction are spring like.  My thought was that mounting securely to a packed sand filled container would remove this bounce and probably decrease the ring.  Has anyone explored this?

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There are several threads on anvil stands and what people prefer.

Just a word on your wording. End grain is the best way to mount an anvil. If they are stacked they are usually laid on their side which is not end grain. Boards/planks/beams stood on end are the way to go instead of building a stack which would have more bounce.

 

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And the sandbox anvil stand has been used successfully for years. Simple to build a tall box that's dimensions match your anvils footprint. Add sand and anvil. Hopefully in that order.

Aside from the advantage of a solid base, it's also infinitely adjustable for height.

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Welcome aboard Rookie guy glad to have you. If you'll put your general location in the header you might be surprised how many of the Iforge gang live within visiting distance.

Not a lot of experience framing eh? Try this for an experiment cut a 2" x 4" say 24" long, lay it flat supported by the ends on a couple bricks so other suitably solid supports. Now sit down on it hard. It'll flex significantly absorbing energy over time. This is called "prolonging impact" and reduces the G load.

Step 2 in this little experiment, stand the 2" x 4" on end and sit down on it hard. It flexed, compressed actually and it prolonged the impact just not much. you need pretty sensitive instruments to measure the reduced G load.

You're making a simple mistake, wood's compressive strength and % of rebound longitudinally is MUCH greater than laterally but it's many MANY times more rigid. If trees were rigid laterally they'd snap in the wind, wind snaps trees off when it flexes them beyond their ability to recover, exceeds their incident of rebound. (I THINK that's the term but . . .)

When you get an anvil whatever form it takes give it a try and see. Lots of guys make anvil stands by laying lumber on it's side alternating 90* between plys, "cribbing" and it makes a reasonably solid stand. Taking the same lumber and screwing it together in a vertical post is noticeably more solid.

There are so many different ways to mount your anvil, build a forge, hang your tongs and hammers, store your stock fuel, etc. etc. it's all too easy for the beginner to get hung up trying to figure out the (mythical) BEST anything and please do yourself a huge favor and forget the perfect anything. Perfection is a cruel joke the universe plays on folk who survived because we can't help but look for better ways to do everything.

Read, practice the TPAAAT method of finding tools but do NOT wait till you find that "REAL" :o anvil, if you hammer hot steel on it, it IS AN ANVIL. PERIOD. The only real way to learn the craft is to build a fire and beat the stuffins out of poor defenseless steel. Reading and talking to us can give you knowledge, but only beating the steel to your will can teach you the CRAFT.

Frosty The Lucky.

Frosty The Lucky.

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  • 1 month later...

Funny my first reply was not posted.  

I'll try again, 

I am mechanical engineer who has studied and published on the engineering properties of wood. I understand very well the consequences of the various mounting schemes I have seen  for anvils on wood.  I understand the mechanical properties of wood thoroughly. Perhaps a more direct way of asking my question is this: do you want an anvil mount that absorbs the kinetic energy of the hammer strike or do you want one that stores the energy momentarily and then returns it as noise and motion?

 

rookieironman

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Hmmmm. I think that's actually more a question of degree than kind.

The better the rebound the better, IF it's conducted at the speed of sound through steel. End grain wood absorbs and stores energy but not in a particularly useful form. Side grain wood absorbs more energy but stores and returns it in a less useful manner. You don't want an anvil on a spring board.

However conducting impact energy and returning it at the resonant frequency of the anvil's face is LOUDER than useful. This is why I like a welded steel stand. It provides a more rigid foundation for the anvil but has a different resonant frequency so when it absorbs impact energy and returns it the different frequencies self damp.

And that is my understanding of what's going on from empirical observation. It'd be fun to set up some tests and see how close I am to maybe right. I'm not an engineer but worked with bridge engineers and resonance, self damping structures, etc. was very much a part of the trade. Still, I wasn't one, I just paid attention.

Frosty The Lucky.

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I'm no engineer either, but I concur with Frosty's take, above. 

I would add, however, that another answer to the question "why a wooden stand?" arises from the combination of tradition and convenience. Welded stands are a fairly recent innovation (although cast iron stands have a somewhat longer history), and the mental image most people get of an anvil includes it being mounted on a wooden stump. It's also fairly easy to get a log or fab up a wooden stand without too much time or expense.

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On 10/4/2016 at 1:26 PM, rookieironman said:

So, I am preparing to begin hitting metal. I am starting to target and acquire tools. I have noticed that anvils are  often mounted on the end grain of stacked  planks.  This seems to me to encourage bouncing.  The mechanical properties of wood in this direction are spring like.  My thought was that mounting securely to a packed sand filled container would remove this bounce and probably decrease the ring.  Has anyone explored this?

Wooden box full of sand is fairly popular.

End grain hardwood particularly elm is traditional though some anvil manufacturers often offered cast iron stands too.

Ringing is really only a problem when you miss the work and strike the anvil IMHO.

If you are worried buy a Fisher they are great anvils and don't ring.

For more efficient hammering get A300-400# anvil the difference is notable. 

3 legged steel stands are popular of late but I recommend thich solid stock legs (1"x2" solid bar minimum) elsewise much energy indeed will be lost to springyness, since steel, as you know as an engineer has a high modulus of elasticity.

The ultimate stand would be a large shaft or solid block of steel securely fastened to  the earth. Something on the order of 6" solid round bar for example though one quickly reaches the point of diminishing returns.

Again if hammer efficiency is your biggest goal consider a very large anvil and mount it very securely.

I don't personally consider an anvil securely mounted when simply set in a box of sand but your miliage may vary. 

 

 

 

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Some of my anvils are in steel sand boxes, but are tightened down with two strap irons, fore and aft on the base. Allthread is welded at the proper angles on the box exterior to enter holes in the straps, then washer and nut tightened. If this is not done, the anvil will "swim" in the sand and take odd angles.

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I think the ultimate stand would be more like having your anvil brazed to a 24" tungsten shaft about 6' long with the excess buried in the ground...

On the other hand I managed to build 3 anvil stands from oak one saturday with the total cost being the time and about $2 for scrap used on the stands.

My Father always told me that *any* engineering equation had to have a "$" sign in it somewhere to really be an engineering equation.

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A sand box stand works a treat on a couple levels: It's almost infinitely adjustable for height, it deadens the ring significantly and it's easy to move, dump the sand in a couple buckets.

One tip to help reduce the anvil "swimming" (Good term Frank, it's much better than descriptive phrase, thanks. ;)) Anyway, if you use crusher run sand the sharp particles will "key" together and all that'll happen hammering on the anvil is make the sand harder. River (Alluvial) sand is rounded and packs only slightly better than  bag of marbles but you can add some fines to help it compact hard so it won't swim.

I'll bet a solid tungsten stand would damp any ring nicely though it'd be easier to tear down the shop and move it to rearrange the shop than a buried tungsten anvil stand as described. . . Still!

Frosty The Lucky.

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  • 7 months later...

Here is my sand box stand. There is not much ring when I use it. I did look into the tie downs ( rods going to the bottom of the box in side ) but I just went with letting the anvil settle in to the sand with use over time. If i did a lot of bending work at the anvil I can go back in a tie it down. I wish I had started this years ago, with my back the way it is now, I don't spend the time I would like to in the shop... I do a lot of reading on this site, I just have not put what I have read into work time.   

Anvil with tray's.JPG

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5 hours ago, mechelement said:

Does the anvil constantly slightly move in the sand as you work? 

 Much depends on what kind of sand you use. Sand that's been tumbled and rounded from the action of water (e.g., a stream bed) will tend to shift more easily than sand made by crushing rock (also known as "sharp sand"). The latter tend to lock itself into place pretty quickly, or so I'm told. 

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Both. Keeps the energy from shifting the anvil about and stops a lot of the ring. Especially one of the beautiful/intolerable cast steel anvils. A soderfors will deafen you inside a year without a decent mounting / magnet / chain solution. My brooks is on a rubber mat with a chain and a couple of HDD magnets; just about quiet enough with ear plugs!

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I don't think it's a question of what's best, but what is the best you can do with what you've got.  

A solid steel stand would be awesome, but who can get one?  A cast iron stand like seen from some makers is also wonderful, but they're hard to come by.  A stand fabricated from steel plate certainly maximizes the performance of the anvil, but if you can't source the metal or weld the metal, you're up the creek.

Wood works well and anvils have been on stumps for ages.  If you can't get a solid wood stump, the best bet after that is making something out of dimensional lumber.  And if you're going that route as a matter of practicality, standing the boards on end is far far better than stacking the boards up like Lincoln Logs.

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Interesting the comment about the type of sand to use in an anvil stand. I dismissed building a box with sand due to what I saw as inevitable that the anvil will shift and sink. Nothing I hate more than an anvil that moves. Was watching a youtube video of a power hammer and the anvil would bounce at each hammer stroke visibly easy 10 mm each time. Atrocious.

Anyway, sand ... I can see that if instead of river sand we used brickie sand, a type of sand that comes from a quarry and has high content of clay, it would compact nicely. Now I am picturing a box full of sand, a steel platform to 'float' on top of the sand for the anvil to be bolted against. Mm ... nothing stopping the anvil from slowly leaning one way or another so ... I can weld a sort of keel under the base, one plate vertically down, 4 or 6" and two halves across forming a cross buried in the sand. This will keep the base horizontal and negate any potential for listing either way. Easy project.

As for the old time tree stump, I think they probably used a real tree stump with roots and all and built the shed around it ... sort of like Odysseus did

There was the bole of an olive tree with long leaves growing strongly in the courtyard, and it was thick, like a column. I laid down my chamber around this … Then I cut away the foliage of the long-leaved olive, and trimmed the trunk from the roots up, planning it with a brazen adze, well and expertly, and trued it straight to a chalkline, making a bedpost of it, and bored all hones with an auger. (23.190-288).

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the More solid the anvil is mounted the more work will be put out per hammer stroke.. 

I have anvils from 100 to 368lbs and I bolt all of them down as solid as humanly possible as they all move even the 368lbs when forging on the side or using the hardie as it should be..

The idea of sand in a tube is great for adjustability..  But it needs a way to be mounted or sucked down onto a solid plate on top of the sand..  as this puts the sand into compression and will hold better as it breaks down.. Yes the sand will fracture with each hammer blow breaks down the grain in slip with side load/crushed..

If large trees a composite stump is the easiest and longest lasting... If you are in an area of large tree abundance than finding a large oak, hickory or ash stump is all good.. Now you just need a way to mount or suck it down to the log..

A solidy mounted anvil will not ring very well as nearly all the vibration will be taken out of it as the harmonics are different between the anvil, bolts and mounts and stump..

Nearly all the anvils I have mounted onto steel stands are nearly quite.. And the anvil I had mounted on my old Maple stump was fastened in such a way that it was nearly quite. More thunk vs ring..

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When I started thinking about getting into forging I just would keep putting it off, do to my Back. I have had 5 back surgery . and going in for my 6th later this month. All this back crap started back in April 1995 in Okla. City..

I hope this is to be my last surgery on my back. At 63 I hurt a lot all over but hell I still can do things. I went with just the rotor forge and the old grill, and it has worked great for me . When I started looking for an Anvil, I was thinking I would just buy a new one. There are two Farrier stores with in 6 to 8 miles of the house, but I waited and found the HB here in Ocala. The stand was going to be a stump, not hard to find a stump here in Fl. just nothing I liked.So I found a pict. of an anvil stand with sand in it and I said this could be easy on my back. And so this is what I came up with. 26" high 12"x12" .. The stand is on a rubber mat. and a step in front of the stand. As I worked with the anvil it was clear that a lot of hammering was not going to work with my back. So I started making pull handles for Barns in this area just heat.... a twist and done. They like there barns down here. The movement of the anvil was more of going down when I first started. The sand had to settle some. 

After the surgery I am going to p/u a gas forge. Turn it on... work an hour or two turn it off and walk away. No cleaning the coal forge....Make a forge you say.... No I need my rest.. I wish I had started down this road years ago. But for now I will keep reading here and try to use the info in some way in my shop.. I hope I did not take this post to far south.. 

Anvil stand 7-4-17 001.JPG

Anvil stand 7-4-17 002.JPG

Anvil stand 7-4-17 005.JPG

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I thought positive connection (lagged straps) to a stump would mitigate the ringing and bouncing around. 

Would setting the anvil in bed of silicone caulk on top of the stump help eliminate the ringing as well? We have a JHM and it's definitely a loud ringer, but is currently on a fabricated 3-legged tube steel frame and sits on a board covered in beeswax within a slotted tray for easy install / removal. 

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