twisting damascus problems

Ryan Minchew

Ryan Minchew

Well-Known Member
Guys,
My brother in law has built a small press and started learning how to make damascus. So far we've made a total of two bars lol the second being a twist pattern where we ran into trouble. The billet started 3 in long and we drew it out to a cube of around 8". We pressed on both side the flat sides and the edges. From here I assumed and that may be the problem, that if we pressed on the edge side and had no delamination or splitting we were good to go. Once we had it long enough we twisted it. After the actual twisting we didn't notice any problems, but once we started flattening it, the edges started splitting between layers.
My questions are
1. Did we have bad welds?
2. Did we keep twisting and let it get to cool?
3 anything else we can try to avoid this?
Thanks for any help guys.
 
Sounds like you may have tried twisting it when it was too cool ? or maybe you did not have temp up when you flattened it during forging ? Just my guess . It has happened to me and I brought up temp and it was fine . Twisting any metal puts a lot of stress on it , I also find that when I make mokume and dont quite have it hot enough , it wants to delaminate when folding or twisting . Just a few thoughts.
 
Twisting damascus can be a pain for sure. It has allot of stress in it and can tear at the seams when flattening. I like to grind the twisted edges off before flattening so they dont continue to tear. I also flux and flatten at welding heat.

One MS I know runs the bar through a stress relief cycle before twisting it. Makes sense.

There is allot of waste steel even if all goes right. Try a bigger billet next time and stay at high temps. I doubt you can even twist it cold so thats probaly not your trouble.
 
Bubba-san And Mr. Bump, thanks for the replies. The thoughts you both mentioned are what my brother in law and I both discussed.

"There is allot of waste steel even if all goes right" I also wondered if this was just a natural part of the twist pattern. It does split or cause some sort of problem on the edges causing some waste. I thought maybe different patterns had different problems and different amounts of waste.

Thanks again guys.
 
You also do not want to start with a square block. press those corners down to round them a little. This was where I had problems before.
 
Your not kidding that there is a lot of waste. I know that when Jerry Rados makes his Turkish he starts with a 9lb billet and ends up with 2 lbs of patterned steel.
 
mike miller said:
You also do not want to start with a square block. press those corners down to round them a little. This was where I had problems before.
Click to expand...

I'll second that, Twisting squares sets up a lot of issues, I always forge to octagonal or round before twisting, not only does this set things up for the twist but it also tests the welds really well with heavy shear forces, if it is going to come apart I want to know then not later. Also after the twist I then do several welding heats to forge the twisted bar into a perfect smooth round with no lines or ridges showing. Take the round down to a square slowly at welding heats and then flatten. With care I have less issues with twists than any other pattern. I understand the material loss in Turkish patterns and composites but straight twists should be the least wasteful of any pattern (other than random), I will take a twist over a ladder any day if I am worried about material conservation.
 
When making twist pattern you have to keep temp up , I dont think you were twisting it cold ? that would be impossible. As you said you let it get cold while twisting. With damascus you are basically forge welding all the time , unlike monosteels . If you dont keep the temp up , it will come apart . Shape is another consideration , a long more narrow billet is naturally easier to twist than a square one , ........
 
One tip I learned was to have a oxy/acetaline rig handly with a rose bud tip, you can save a lot of in and out time pluse you can localize the heat.
God Bless
Mike
 
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