Zach,

You are trying to achieve something few people have been able to do consistantly in our generation.

First, you have not said what type of forge you are using. Coal? Gas?

Second, Typically 15N20 is cut from band saw blades which is pretty thin to be the outside layer. It will bow up and you will get oxidation and bad weld. I suggest using thicker material on the outside. In fact, there are several things that you are doing that will be decreasing your odds. Not impossible, but for a new guy to forge welding, I would not bet on your being successful.

Lets start over. Your billet needs to be in as compact a bundle as possible. Yours, as it stands, is about 1/2 inch X 1 1/4 X 6 inches, right? That's spead long and thin already. The odds are,

1: you will burn it

2: it will bow and oxidize.

3: not near enough material for reduction at the first weld. (need 40-50%)

4: The long thin bundle wont likely be able to handle the welding heat unleass you have a digitally controlled forge. The more compact the bilet, the better it can protect itself from burning. Lets think like the steel for a minute. The closer a stack is to a cube, or better yet a round ball, the better the mass can handle absorb the heat from the atmosphere of a forge that is not digitally calibrated. We cant make a round ball, but we can mimick the cube to as close an extent as possible. The shape buys you a little time whereas a long thin billet, will take much more control in the timing department.

Here's what will better your chances. Shorten the stack and increase you starting layer count. Instead of 3 layers, try 6 layers and half as long for a stack 1 inch X 1 1/4 X 3 and I would re arrange the stack with the thickest stock on the outside. I prefer to make as large a billet as I can but I understand you dont have a power hammer.

There are three things to control here. Heat, oxidation, and timing. Fiddle around with either and it wont work.

Heat: Get it hot enough and make sure you know how to recognize whether the billit is ready to stick together.

Oxidation: Prevent oxidation, whether you use borax or other means. But remember, YOU are part of the antioxidation equation. In other words, keep it covered with borax, get a reducing atmosphere, and be very attentive about it.

Timing: Do all of you thinking and planning BEFORE you bring the billet out of the forge. Have you hammer and anvil ready. You have mere seconds to bump it together. Be out of the forge as short of time as possible and flux and go right back in. Make several short sessions of hammer bumps rather than trying to move much metal. After you get it good and stuck, start moving the metal.

Zach, Lin has excellent advice. I cannot add much, except to say when you go to set the weld, start at the handle end and weld it up in sections, moving towards the end. It does not take much pressure to make the weld, if you have the other variables in check. The correct welding heat, flux, and a reducing atmosphere. Definitely thin sections on the inside, as Lin says warping at heat is a big issue with the thin steel. Good choice for the steel. My first attempt was seven layers, three 15n20 and four 1080. It was four inches long and one inch wide. I used a gas forge and borax for flux. You want to flux when the billet reaches at least a red heat, then put the billet back in and allow it to come up to welding heat. The flux should look like it is flowing over the billet and slightly sizzling. The billet should be a yellow orange color. I admire your want to on this. I stopped at 28 layers on my first billet, then decided a power hammer was a definite addition to the shop. It can be done, just takes a long time and lots of arm power. Let us know how it goes.

Brion

Lin and Brion thank you for your replies.

I have a diamondback ironworks 2 burner forge.

The reason i was going with 3 layers is because i wanted to make a San Mai knife.

.095 was the thickest i could get the precut and ground steel from aldo.

Should i add a second layer of 15n20 on the outside then?

possibly run a small tack weld line on the opposite side of the handled end so the doesn't curl up?

Zach

I used to weld with my hammer and anvil. I made several Damascus knives this way until I built a rolling mill. Even then, I set the welds by hand. As Lin stated, mass is your friend when hammer welding. It buys you time because the thicker billet will not cool off so fast. I always used billets over 1". Another tning is to heat up your anvil. Either heat up a big thick plate and put it on your anvil, or get a magnetic engine block heater and heat up your anvil with it.

Usually when I do San Mai, I start with all pieces 1/4" thick. I would suggest thicker material-- again for the mass and heat. Doubling the 15N20 on the outside will help, but you are still going to have to contend with the thin layer. It can be done and I have done it, but it was with a press. I am sure that this could be hand welded as well, but really keep track of what you are doing.

Something else you may try is to dry weld your billet. The way to do this is to build up your billet and clamp it together. Now keeping everything tight, weld all the way around the outside of the billet sealing all the edges. Do this in one pass making a wide bead that covers all the seams. One weld pass all the way around the billet. What you have now is a billet that air cannot get into. No air = no scale. This is how I do all my San Mai billets but have not done it by hand welding. You will lose some material as you will have to grind off the welds around the edges of the billet, but it is another option.

Brian

|quoted:

Zach

I used to weld with my hammer and anvil. I made several Damascus knives this way until I built a rolling mill. Even then, I set the welds by hand. As Lin stated, mass is your friend when hammer welding. It buys you time because the thicker billet will not cool off so fast. I always used billets over 1". Another tning is to heat up your anvil. Either heat up a big thick plate and put it on your anvil, or get a magnetic engine block heater and heat up your anvil with it.

Usually when I do San Mai, I start with all pieces 1/4" thick. I would suggest thicker material-- again for the mass and heat. Doubling the 15N20 on the outside will help, but you are still going to have to contend with the thin layer. It can be done and I have done it, but it was with a press. I am sure that this could be hand welded as well, but really keep track of what you are doing.

Something else you may try is to dry weld your billet. The way to do this is to build up your billet and clamp it together. Now keeping everything tight, weld all the way around the outside of the billet sealing all the edges. Do this in one pass making a wide bead that covers all the seams. One weld pass all the way around the billet. What you have now is a billet that air cannot get into. No air = no scale. This is how I do all my San Mai billets but have not done it by hand welding. You will lose some material as you will have to grind off the welds around the edges of the billet, but it is another option.

Brian

where do you get the 1/4" thick 15n20. i wish aldo had it, but to no avail.

Zach,

Finding 15N20 thicker than what you have is hard to find. Aldo had some this fall. Give him a call to see if any is still available.

If not, I would do what Brian suggested and use multiple layers of it and weld all of the seams along both sides. This will help with the warping of the thin layers.

Gary

thanks guys. i think i am going to double the layers of my 15n20 and also run a weld around each of the layers.

I will probably get to this around thanksgiving. i will try to remember to take pictures!

Well, I'm a novice too but I found that welding both ends and attaching it to a handle really helped. I got too much movement with only one end welded. For what's it worth - my first ladder and twist patterns are below

The twist was supposed to be a feather pattern but I lost track of the bar oreintation. I did these in a class with a blacksmith and duplicated them this week at home. I used a hammer and anvil too and except for the drawing out it wasn't too bad. I really need a running power hammer for that. Even drafting my son to strike for me, it was a lot of work

Anyway, the welding both ends really help me...

Kevin

|quoted:

Well, I'm a novice too but I found that welding both ends and attaching it to a handle really helped. I got too much movement with only one end welded. For what's it worth - my first ladder and twist patterns are below

The twist was supposed to be a feather pattern but I lost track of the bar oreintation. I did these in a class with a blacksmith and duplicated them this week at home. I used a hammer and anvil too and except for the drawing out it wasn't too bad. I really need a running power hammer for that. Even drafting my son to strike for me, it was a lot of work

Anyway, the welding both ends really help me...

Kevin

Thanks for the support!

is that a cold shut in the bottom piece? just low and right.

|quoted:

Thanks for the support!

is that a cold shut in the bottom piece? just low and right.

No, it's actually a bit of the center piece sticking out. I wasn't as carefully as I should of been grinding the center strip to size and it sticks out about 1/32 and gives a shadow. The most of the cold shuts are on the other side I didn't show. I rushed the last preparation and weld and it shows. None of them are deep and I think I spent a bit more time on the preparation, it would be nicer. Both should grind out as the bar is about 1/2 inch thick. I need to cut off the areas with the tig weld and start cleaning it up as soon as my real job allows.

The little dark spot before that appears to be one thro (more to the center). <img src=' http://www.americanbladesmith.com/ipboard/public/style_emoticons//sad.gi f' class='bbc_emoticon' alt=':(' />

I found that material prep is much more important that I thought: not only to get the weld to stick to but also to prevents the uglies. Hopefully I can take Mr. Cashen's class on Damascus this spring and learn to do it right. There appears to be a whole lot more to making Damascus besides the weld.

Kevin

Zack I have done a couple damascus blades forged entirely by hand, I have also tried doing the 15n20, 1084 san mai you are talking about. Like you I think I was suprised at how difficult it was. I had little trouble with the damascus, aside from the problem of drawing out a piece of steel that big by hand, but the san mai didn't work out as well. First like Lin said the outer layers bowed badly. On the first try I had just tacked the corners, for the second I tacked the middle as well. It still bowed out and in the end one side of the billet welded properly the other had an enormous inclusion that left it unusable.

I believe the best bet would be what Brian suggested, welding around the seams to keep any oxygen out.

Personally I would have a go at welding up a typical billet first, If you keep it fairly small and use a spring fuller to draw it out it isn't that bad.