Blacksmithing : Forge Welding Cable Damascus

I' m interested in trying the steel cable damascus knife, any advice?

Cable is actually really nice stuff to weld. There are a couple of tricks that people forget that help a lot.
The alloy in the cable has a good success of welding even at fairly low temperatures. Having said that use a full welding heat until you are comfortable with it.

Crane cable is better than elevator cable. Elevator cable has an inner core twisted one direction and an out sleeve twisted the other direction. This is called counter rotating cable. That is the cable doesn't twist as it spools off the drum.

Regular crane cable has inner and outer strand twisting in the same direction.

What this means and this is the important step, when you first heat the cable up, clamp it in the vise and twist it as tight as you can get without it buckling. This helps close up the air spaces for better weld. The elevator cable won't twist tight as the inside is expanding when the outer sleeve is being twisted tight, causing spaces to open up.

Back into the fire and take up to a nice orange.
Gently wire brush it, and add flux.
Back into the forge to take the welding heat.

The next trick is instead of welding flat on the anvil (although this does work) use a U shaped bottom swage tool or swage block to help support the sides of the cable when you weld.

As you make the actual forge weld rotate the cable with the direction of the strands. That is each hammer stroke is actually tightening the twist.

You will find that once the cable strands are weld the feeling of the metal changes from the floppy cable to a hard bar. Once it is well stuck together as a bar take a series of refining welds on all edges to make sure any loose strands are tacked down.

When you are completely satisfied that it is well welded then stretch out as normal and make your knife etc. as usual. Once completed, ground, hardened, then sanded again then you can etch in acid to reveal the pattern. You can use vinegar warmed up on the stove. Takes along time but will give you a bit of the pattern, and is the safest acid.

I use more aggressive acids such as sulfuric or nitric or some times ferric chloride. Follow all acid precautions with these strong acids.

Neutralize and take a look at your knife.

David Robertson
Artist Blacksmith

What is The Best Steel for Making a Blacksmithing Slitting Chisel From?

What is a Slitting Chisel and What Steel Should I use For it?

A slitting chisel is a very thin flat chisel used for opening or splitting steel when it is hot. The steel has to be very resistant to heat so that it doesn't deform as it is hammered through the steel.

Most slitting chisels are about 1 inch wide and the edge less than 1/8th of an inch thick. If you are planning on making curved cuts consider making a slitting chisel about 1/2 inch wide. (The smaller the width the tighter the curve you can make!)

I usually try to make the chisel about 8 to 10 inches long. My preference for making this tool is H13 steel or S7 steel. Both of these steels are heat resistant and stand up to the heavy abuse. They are a bit difficult to forge down to size but it is worth the effort as they last much longer than other steels.

I have used coil truck spring. This is an alternative and will do in a pinch but this steel is not very heat resistant. This means that you can't work it down so thin and if you let it show a bit of color as you are hammering through the edge will deform. Then if your chisel doesn't get stuck you have to sharpen it. As I said it will work but not as well.

I have had good luck using old jack hammer bits which I believe are S5. They stand up to both the heat and the hammering.

Good luck making your chisel and it doesn't hurt to have 3 different sizes. 1 inch , 1/2 and 1/4 inch for detail work.

David Robertson
Artist Blacksmith.

Blacksmithing | Can a File Make a Good Knife?

How to Make a Knife From a File?

I have a bunch of old and fairly new files of all sizes. I would like some information on the proper procedure in turning them into a decent blades.

Hi
Files can make decent knives but you have to do a fair bit of preparation first. To truly make a good knife I would suggest grinding all the teeth off so you are down to bare metal. If you forge the blade and the tang leaving the teeth on. All the valleys at the bottom of the teeth make small creases in the surface of the blade.

When you heat treat the blade these creases can form cracks or potential cracks, and are always a point of weakness.

In general file steel can be an unknown tool steel and I have heard there is considerable variation in quality. I would try quenching in oil for most. I would actually recommend buy new steel. O1 drill rod is easy to get and makes a good knife and most importantly you know what you are getting. Buy 3/4 or 1 inch round and just forge it flat then make your knife from that.

It might seem a little expensive to spend $30 or $40 on a piece of steel 3 feet long. If your knife breaks in the final heat treating after spending 10 to 20 hours on it the $10 spent on the piece of O1 used for the other knife seems pretty cheap.

If you are stuck for finding O1 and tool steel in your area try clicking through to Onlinemetals.com They carry a full range or sizes.

I have had a number of knife making requests lately so I am planning on doing a newsletter series on it in the near future.

I hope this helps.
David Robertson
Artist Blacksmith

How to Deaden The Noise of an Anvil ?

How Do I Decrease the Ring of My Anvil?

Hi
There are a couple of tricks to deaden the noise of an anvil a bit.

I do use a chain but the secret here is that it is a fairly heavy chain and you wrap it around the anvils waist. Then it must be bolted down very tightly to the stump or stand that supports the anvil. This does help deaden the ring significantly. The idea is to tightly clamp the anvil to its base with the chain.


You can also add a good sized magnet under the horn or the tail of the anvil. This will collect scale but it helps remove some of the ring as well.

Another option that I don't like as well as the others is to take a short length of chain and make a loop out of it and hang a weight off it. Then place the loop over the horn or the tail of the anvil. It too will help deaden it down the noise a bit, but as soon as you need that spot on the anvil it is in the way and has to be moved.

Hope this helps.

David Robertson
Artist Blacksmith

How to Avoid Distortion Heat Treating Damascus

How Do I prevent Scale Build up When Heat Treating a Knife?

Well making my third Damascus knife 13 layers ,when i get it polished and to the point of tempering when i put it in the gas kiln red hot to loose magnetic it warped every which way .made out of all the same coil spring steel and hammer welded plus all sorts of slag all over it now so while it was red hot gently hammered it straight again and annealed . so how can i get it polished perfect and temper with out slag and distortion next time now after i sand and polish it again ? whats to keep it from happening the next time I go to temper it ???

Hi
This is a little tricky to answer as I have not seen all the steps that you have gone through.
Slow cooling (annealing) in vermiculite or wood ash to relieve the stresses is very important. This should remove much of the tension between the two different types of steel. This should help reduce the warpage when you heat for quenching.

If you are heating the blade in a gas forge hold it so that the back is up and it heats evenly from both sides this should help with the distortion as well. It should only be heated just past the magnetic point. It doesn't have to get super hot. Then pull the blade out and test with a magnet until it just pulls then quench the whole thing in the appropriated quench medium. Water or oil. Then temper evenly 425 degrees in a toaster oven. Then a quick sanding and hold the edge in a water bath (about 1/4 inch deep) and paint the temper colors on the back with a torch. Blue on the back straw on the edge.

Then sand to final finish always keeping the edge and the blade cold by dipping in water.

In short I rough grind and sand to about 80 grit before I heat treat. The final sanding is done after the blade is hardened. When I harden there will be some scale formation but it is really very little as it is only up to color for about a minute and not very hot. Just enough to lose the magnetism.

I know some people use a nickel foil to wrap around their blades so that it doesn't oxidize very much. I have not used this technique but understand it works well. You would have to source a knifemaking supplier for the nickel foil.

Hope this helps.

David Robertson
Artist Blacksmith

Blacksmith Coal Forge Hood and Chimney

What do you need to take the coal smoke away from the forge when you build a coal forge?

I fire mostly propane so fume exhaust is a little bit less of a problem.
Coal forges definitely require a chimney to exhaust the smoke. There is a great deal of smoke
created when you burn coal.

Essentially you have two options

The first is the easiest and that is to make a large funnel shaped sheet metal hood to catch the smoke. It should enter into a 10 inch pipe (much smaller does not draft well for a coal forge. 8 inch diameter you take your chances on) This pipe should extend through your roof and ideally be 2 feet above the ridge line of the building. If you are in an area that requires building codes to be inforced you may have to use insulated stove pipe.

Coal smoke is actually much cooler than wood smoke and in reality does not need the insulated pipe but the building inspectors have no reference for this.

This hood works moderately well. You can start the draft by crumpling a couple of sheets of newspaper and lighting them on fire when you start the coal. Once the draft is started it is pretty easily maintained with the heat of the coal fire.

The second option is more complicated to construct. But works well. It is a Side draft chimney.

For plans google "side draft forge" or "side draft chimney for forge" you should be able to find something. It is basically a box that has a low opening in the side and a shelf inside the box that catches the smoke. The chimney draft sucks the smoke to the side and out of the way.

Good ones work very well. Again you may have to discuss chimney designs and materials with your building inspector.

Coal produces alot of smoke on start up, then simmers down as it converts to coke. Hardly any smoke with a coke fire. Charcoal works well too with very little smoke although you need some chimney to carry the fumes away from your work area.

I hope this helps. Good luck building your forge. Coal forge is the most versatile but it is a bit of a trick to get on to. It is also the easiest to build.

Take Care
David Robertson Artist Blacksmith

Blacksmithing : Anvil Height

What is The Best Height For My Anvil?

Hi David
Thanks for all your emails they are really inspirational, I have just got my old gas forge, anvil and leg vice back off my uncle who never used it a bit rusty but no worse for wear, my question is this I have read somewhere that the correct height for a anvil is if you stand up straight with your arm down by your side and make a fist the height from the floor to your knuckles would be the ideal height to the top face of the anvil is the correct, my anvil and steel stand is about that height but it just feels a bit low for me? the other thing is if I use a stump of wood as a anvil stand what is the best wood to use?

Many of the old books on blacksmithing use this standard for anvil height. I too have always found this a bit low for several reasons. If your arm is close to full extension, the repeated impact can damage your tendon in the elbow if not the joint as well.

I have my primary anvil set at wrist height as I stand beside it. This creates more flex in the arm acting as more of a shock absorber. I do lose a little power having this flex but I prefer to err on the side of self preservation.

The other issue is that the lower the anvil is placed the more you will find yourself bending over. This creates strain on your back. Some thing to be avoided in later years. This is especially true of light work where you tend to get closer to see what is going on. Heavier work should be done in a more vertical position.

Mounting the anvil.
Mounting on a stump is good. I am not sure that the type of wood makes as much of a difference as the weight. I have seen some steel anvil stands (3 leg) that were quite heavy and worked well. The important part of this is that the anvil needs to be bolted securely down to the stump. This effectively adds the weight of the stump or stand to the anvil. In some cases this could add an extra 100 lbs. If the anvil just rests on top it, it looses efficiency as it bounces around.

This will help in the stability and the performance of the anvil.

A box filled with concrete with bolts for tieing down could be effective. I don't like the sand boxes as the anvil floats too much on top and you have to keep leveling it.

A lot comes back to personal preferences, but this is what I have prefered in the past.
Hope this helps.

David
www.artistblacksmith.com