Forging Damascus steel, part 1

In addition to woodworking, I dabble a bit in blacksmithing. I have some good friends who are blacksmiths and I visited their smithy this weekend. We decided it'd be fun to practice our forge welding and try to make a billet of Damascus steel.

Of course I didn't think to start taking pictures until we were well into the project. Here's a quick description of what we had done up until I started taking pictures:

We started with a piece of 1" x 1/4" x 6" 5160 spring steel. I took a larger billet of wrought iron and forged it down to match the size of the 5160. Forging wrought iron is really fun and a a different experience from forging steel. The wrought iron moves very easily and must be worked very hot to keep it from splitting.

I next used bailing wire to bind the two pieces together. The whole thing went into the forge to heat. Once they reached the proper temperature, I struck the pieces on the anvil to forge weld them together. It took me a couple of tries to get the heat right; the first few strikes were at too cool a temperature.

Note that when I say "too cool" I'm talking in the range of 2000 degrees F. Welding temperature is just at the point where the surfaces of the steels are almost molten, which can be 2600+ degrees F.

After the two pieces were welded, we cut the blank in half, stacked the two halves and repeated the process.

Which left us with this 4-layered billet. We now need to get this billet back to being 6" long so we can cut and stack it again. To accomplish this we "draw out" the steel.

To make this process easier, we used a treadle hammer. This evil-looking device has a 75lb hammer that comes down and strikes against a fixed anvil when you step on the pedal. You'll notice the hammer and anvil parts are round bars. This creates dimples in the steel, causing it to stretch out as we want.

After the treadle hammer, some hand hammer work on the anvil is used to true up the faces and keep the sides from spreading out wider than we want.

And here we have the piece all drawn out, back to 6" long again.

Now came time to cut the piece in half again. A few seconds at the cutoff saw yielded a beautiful shower of sparks.

We now had 2 billets again. We stacked them to make an 8-layer billet...

And wired them together in preparation for another forge weld.

Once the pieces come up to welding temperature, they're pulled from the fire and struck on the forge. The initial strike produces a small spray of motlen metal, slag and other impurities that were in the joint. It's spectacular to see, and I tried to capture it with this photo.

After the first weld, the bailing wire is snipped off and the other end of the billet needs to be welded. This picture shows the application of the Borax flux, which is used to help drive out any impurities and give us a good clean weld.

These pictures show the "cave" type fire we made. The coal is piled around the fire pot. As the green coal turns into coke (much like wood turning into charcoal, where the impurities boil off without the wood burning) the walls and ceiling of the cave become one mass and help to make an even, hot fire that's good for welding.

This is the second weld. It's very interesting how the sound of the hammer strike changes when welding. The first strike or two is a softer 'thud', then as the pieces cool from welding temperature the sound changes to the more familiar ring of hammer on steel.

We now have an 8-layer billet! It was a fun and productive weekend. We still need to do more drawing out, cutting and folding. And of course we need to make a finished product from the billet. More to come!