I know the basic method of mosaic damscus.
for example [ ] represents a a endview of a tube in which I could place a pattern say [><] the x represents the pattern and the white between the x represents another alloy of steel.

What next after I weld it up?

Could the pattern also be made the lentgh of the box?
say like this
-----------------------------------------------------
xoxoxoxoxoxoxooxoxoxoxoxoxoxox
------------------------------------------------------
Then weld the lid on and slice the box open length wise?

Can this be done say in smaller tubes with a hammer, instead of a press?

You've got the right idea. True mosaic is a series of tiles which are basically arranged and then welded together. If you were to create a "tube" as you mentioned, slices are cut and then arranged edge to edge and welded to create the finished piece. This has some marked disadvantages in that it is very weak with all those weld lines running across the flats of the blade.
Many of us create mosaics by welding several billets together in such a manner that the pattern is on the ends of the bar. The bar is then cut to look lik a zig-zag, and folded open (like accordian folded paper) this is where we get the term "accordian folded". It is a long process, that wastes a lot of material. However, there are no weld lines running across the blade, making for a much stronger end product. Once I get my computer back up and running, I'll post some pics of what an accordian fold looks like.
As for doing it with a hammer............it's tough. I was having about a 75% failure rate until I went to the press. The key to mosaics is an even compression throughout the piece. Some folks have done it with power hammers, but those who have been successful use large machines, with BIG flat dies, where they can get the whole billet under the hammer at one time. It will work if you are using bars of steel versus powder. Powder requires more compression to weld than anyone can exert by hand.

Ok, so, an accordian cut would be say one cut almost through the bar, go to the other side of the bar and cut almost through to the other side, continue down the bar, cutting alternate sides. heat and open it up?

We started this thread over at keenjunk.com a smith there was looking for information. Actually there is none that I could find.

I had a a desription of your spider mosaic on floppy disc, but I think the file fairy's had it for lunch. I did find your firestorm description.

Is it just me or is mosaic kinda baffling for a long while, until you start playing with it?

Again, you've got the right idea. The straight cuts will work OK on the simpler patterns, but the more intricate you get, the more the cuts must be modified to prevent failure. Rather than cutting lines straight across the bar to be accordian folded, I cut a series of "Vs".
When you attempt to open the folds, there is a great deal of opposite stresses. On the inside of the cut, the material must expand, while on the outside of the bar in must compress. These forces are in very close contact with each other. With straight cuts you often will get "fish lips" on the outter edge, and tearing on the inside of the cut(s).
The trick to making it easy is to use a great deal of care when setting up (marking out) the bar for the cutting operation. The cuts need to be the same depth from side to side, with equal distance between cuts. Otherwise as you open the bar up, it wants to "wander" around creating curves and even a bar of various thicknesses. I find it much easier to open the bar up at welding heat as this will help prevent any tears, and if for some reason there is seperation, it will weld right back together. As I said before, it is a very wasteful process. Once you get into it, and have a few failures, you'll see just how obtuse some of the patterns can be to accordian fold. But.........Don't let it defeat you! Keep after it, and it will become second nature.

Good explainations Ed and I would like to add one more tip that I use to eliminate those failures during unfolding. I always cut the V's in the opposite direction as my last weld. So that your not stressing the last weld you made in the billet as this is always the weakest for one reason or another. My success rate in unfolding is almost flawless everytime since I started doing this. The only way to see the possibilities is to do it and experience will help more than anything else as well as open a flood gate of ideas.

I understand the accordion thing, I've seen it a few times though I don't have the setup yet to work on the mosaic. I am curious how to effectively weld tiles side by side, though. It makes sense that that would be the weak link in the blade, but what's the easiest way to do this?

Jamie

Hi Jamie!

Whenever I do a true mosaic, I create a bar with whatever the desired pattern, at least 1" square. I then slice approx 3/8" thick slices. Each edge is ground to a 30 degree angle. The pieces are then set up in such a manner that the edges are overlapped, and then I spot weld it all together. When the setup is finished, you'll have a bar that is held together with spot welds, and it will look something like......

-_-_-_-_-_-_ Not a great image, but it's the best I can do with the keyboard.

Next I use the press (or you can carefully do it with a hand hammer), and make the welds. There will be overlaps, and the surface will be a bit uneven. Once all the welds are made, and the billet is annealed, I got the the angle grinder to even the billet up, and if you do not have access to a surface grinder, you can finish flattening the bar with the belt grinder.
A billet that is welded in this manner does not react well to forging to shape, so the best method, once the bar is flattened , is to stock removal the rest. As I mentioned previously, this design does not have a great deal of strength due to the welds running across the blade. As Tom mentioned above, another good point is that the last weld made, is always the weakest in a billet. Good Luck!

So, would the san mai technique be a good use of these tiles?

That is exactly what I do when I want to use tiles in a blade. However the san mai technique only looks right if it is done right. Meaning the smith must use a thin enough core so that when ground it only shows a little if any at the edge and a great deal of care must be taken while forging to keep it in the center of the blade. I use 1/16" material for my cores. It will make a stronger blade than if the tiles are used seperately. This can be a very intense blade to forge and time consuming as well but can pay off in the end result.

I hadn't thought of that. Thanks