Step 1: Technological Ingredients
Something to abrade steel with, I used a file and an angle grinder
A welder of some variety. I used a basic stick welder, though a MIG would have been easier to use.
Wood butchering equipment. I used a chainsaw and a hatchet but there are many other tools that could work
Drill - electric or otherwise
Personal Protective Equipment
Welding mask with correct filter glass - wear this when welding, obviously.
Protective clothing - Wear tough, close fitting, non flammable clothing when working with hot, heavy, sharp or fast moving things.
Protective footwear - This should be strong and non-flammable so they stop your feet being crushed and burned as badly.
Safety Glasses - May as well wear these the whole time, it's amazing how often stuff bounces off them.
Ear muffs - or other hearing protection. Wear when using loud tools.
A lump of railway line or other heavy steel section. Finding this can be difficult if you don't want to spend too much cash but scrap metal dealers are a possibility. Looking around railway tracks may be dangerous and illegal depending on where you live.
A piece of heavy steel plate. This spreads the impact loads over a larger area of the wooden stand, increasing the effectiveness of the anvil somewhat. It also makes it easier to mount. I used a railway fish plate which is convenient because it already has mounting holes.
Step 2: Prepare the parts
On the end of the railway line to be welded I ground a heavy chamfer to aid weld penetration. When the parts were ground clean I test fitted them, removing more steel where necessary to get a close fit.
Step 3: Tack and weld
Welding stuff this heavy properly would probably require more power than can be supplied by a basic 240v AC single phase stick welder. In this application however, the strength of the weld is not particularly crucial. I didn't have any electrodes other than these quite small ones on hand, so I invented the trick you see here in the second picture. It worked well enough for me, but I'm not a welder.
Step 4: Stumping
WARNING: Chainsaws are really really dangerous and like to bite. Don't chop any limbs off or anything please.
Other combinations of concrete, steel and timber would also work well as an anvil stand. A good mounting will increase the effectiveness of the anvil and reduce noise.
I used some small pieces of steel plate and coach screws to attach the rail to the upright section of the stump. I also hammered steel spikes through the holes in the fish plate and bent them over.
Behind the new anvil on the top of the stump, I cut a notch and hammered in a small piece of light gauge rail. This provides more useful edges and surfaces on which to hit things.
I have not used this anvil extensively yet and I'm sure it will be modified later on. It does however seem to be pretty useful, and is good value for the effort required to make it.
Step 5: New ideas
This design was derived from discussions on the Anvilfire discussion forum, with input from a number of members including the Anvilfire Guru. See the archived messages here, click on June 1 - 7, 2007 log.
Would halving the length of the upright sections reduce performance considerably? the second picture has tentative dimensions.
Any other comments?
I added another drawing showing a second possibilty, involving a single upright section with a continuous face/horn piece welded on. Which is better?
AND ANOTHER EDIT
I decidd to go with the heavier option. No photos of construction unfortunately. The parts were cut using an oxygen/acetylene cutting torch and partially finished with an angle grinder. Welding was done with a MIG welder. My future holds quite a few more hours with an angle grinder.