Thread: Air hammer?

Now I am getting carried away, but I really like the idea of making Damascus and San Mai (Tapatalk inserts the caps) so I am thinking of building a small air hammer like Larry Zoller's.

My question is: how small can you go and still be useful?

I have a piece of 2.5 inch round stock 5.5 inches long with 1/2 inch threaded end from the end of a farm axle, which I was hoping to use as the hammer head, but that's only about 8 lbs.

I got some 4x4x.125 tube and 10 ft of 4x 3/4 flat bar that I was going to stack into an anvil 30 inches high (lengthwise). Man, everything is expensive.

A friend has a valve for trade but it is 12v solenoid activated so I will need to find an electric roller switch. I only have a cheap 110v air compressor, but that should be ok for light use, I reckon.

Hoping I can find all the main pieces and some more scrap before this gets too expensive!

I'm sure you can get it to going, not sure how efficient it will be...but I'd love to see it anyways!

I have no idea... kevin cashen sez below 100 pounds can only do small billets and may not weld as quick as is ideal... google matherton forge and look at damascus section to see if it makes sense to you.

Originally Posted by AndreGrobler

I have no idea... kevin cashen sez below 100 pounds can only do small billets and may not weld as quick as is ideal... google matherton forge and look at damascus section to see if it makes sense to you.

I would have thought hammer size would be more of an issue with drawing the billet out than welding it. It's not like you have to whack the bejeebus out of it to set welds.



But being a rookie at this, I'm interested to hear what others think.

EDIT: maybe get in touch with David Robertson. He's an artist blacksmith here in Ontario who builds and sells plans for air hammers. He has proven very helpful to me in the past re forge and burner building. Good guy. www.artistblacksmith.com

He has a whole story that makes sense, and it starts at the way you choose steel and the size of the building blocks... which requires a larger hammer....

There are power hammers as small as fifteen pounds (7 Kg) that will perform.

The first issue is the skill level and experience of the operator. Get to some smith's shop and learn how to use a hammer. Start with a hand hammer and work at it until the steel does what you want regularly. If you can afford to pay a striker, (feed them, beer them etc.) you can get a feel for what a power hammer might do for you. Either way, if you don't learn the hand hammer, the power hammer will only magnify your mistakes and waste time and resources for you for efficiently.

The second issue is to use what you can afford rather than chase off after the latest greatest or the biggest. There has been a lot of forging done on smaller hammers than you would think. Maybe set your sights on a 12Kg falling weight and call it good. Then if you find that it won't hit hard enough for you, you'll have made enough stuff to both pay off the expense of building your air-treadle hammer and to see that a bigger hammer is going to be more cost effective in the long run.

I had a chance to use one making tongs recently and had a blast. Sure takes the wear off the arm for drawing out the reins!

When we make Damascus, we always set the welds by hand on an anvil. You don't need to bust your shoulders doing it, just firm hits to weld it. Then we use either a hydraulic press or power hammer to draw it out. If you rely on your machinery to weld as well as draw, you may end up with voids.

If you can make it up to Edmonton, look up Shawn Cunningham.

Can somebody help me with the switching? Does a typical hammer have just one switch/valve positioned at half-way across the travel of the hammer head, or two at either end of its travel?

It seems to me that if there's only one, the air will already be working against the downward movement by the time the hammer strikes, no?

If I get that far, I will include a regulator on the exhaust of the up side so the up velocity is slower than the down.