Mosaics-Plus or Minus

[Gary Mulkey]

Recently I have been laminating or San Mai'ing most of my mosaics to a 1084 core. This obviously makes the damascus mostly ornamental.

I thought that it would be interesting to hear from you on the usability of mosaics and whether laminating adds or subtracts from them. To me, the grain direction of a mosaic isn't ideal for usage but would like to hear opinions from the rest of you on this. Is any possible added strength worth giving up the damascus cutting edge and any possible advantages there?

We haven't had a good theoretical discussion for a while and this could make for some goods view points and exchange.


Gary

[Mike Turner]

Hi Gary,

Well I think it is a matter of construction. I have been making "W's" lately and I do loafing, then cut a piece off the billet and forge it out. I know others like Bruce Bump make similar billets but keep his taller (blade length) and cut slices off and finish forging the blade. which is less stressful on the welds IMHO and nothing wrong with it.

Now tiling I think the strength is based on what pattern is being tiled. I would san mai it myself and since I am not really a stock removal guy I would forge the bevels in so in essence the pattern goes nearly to the cutting edge. Now if you really wanted the damascus at the cutting edge just put a blind core so to speak just for structure and forge to shape so not to expose it.

[Gary Mulkey]

Originally Posted by Mike Turner

Hi Gary,

Well I think it is a matter of construction. I have been making "W's" lately and I do loafing, then cut a piece off the billet and forge it out. I know others like Bruce Bump make similar billets but keep his taller (blade length) and cut slices off and finish forging the blade. which is less stressful on the welds IMHO and nothing wrong with it.

Now tiling I think the strength is based on what pattern is being tiled. I would san mai it myself and since I am not really a stock removal guy I would forge the bevels in so in essence the pattern goes nearly to the cutting edge. Now if you really wanted the damascus at the cutting edge just put a blind core so to speak just for structure and forge to shape so not to expose it.

I have been tiling my most of my mosaics and rewelding directly to a core recently mainly for added strength. Even though I will occasionally extend the mosaic completely down to the edge, I suppose that it's not a true hidden core. It might be interesting to partially cut the spine of the billet and weld a true hidden core down it's length (ala the Japanese sword makers). I suppose that in doing this it might even be advantageous to use a low carbon steel for the hidden spine. Has anyone had success with doing this?

Gary

[Ed Caffrey]

This is an interesting topic....I've looked at this thread about 4 times now, considering it....as with most things in Bladesmithing, the end quality is going to depend totally on how well, or how poorly the Bladesmith does his/her job.

There are MANY factors that come into play, from the initial welding processes, all the way through how the blade is thermal treated.

Specifically with San-Mai construction, much depends on the base materials and how they interact with each other, particularly in the forge welding process. Is the welding technique such that it achieves good, solid welds? Do the materials used in the San-Mai "compliment" each other in terms of compatibility? For example, it's much easier to create a stable, durable Mosaic/San-Mai blade if the materials are similar (something like a core of 1080 and a mosaic overlay of 1080/15N20.
Things become more difficult when you attempt to put dissimilar steels together....for example a core of 52100 with mosaic overlays of 1080/15N20.....it requires much more concentration and understanding of the materials to overcome the obstacles.

Over the past year I have spent a great deal of time and effort on Stainless overlay San-Mai construction, and found that to achieve what I consider a "good" blade, I basically had to re-learn many of the basic tenants of forge welding, thermal cycling, and heat treating when it came to that material. It took a lot of experimenting and wrecked blades, but I finally managed to achieve outstanding results with 1080/15N20 mosaic cores, overlayed with 416. At first I thought I'd never get a good cutting blade, but once I realized that I had to rethink my procedures, based on the characteristics of the materials and how they interact with each other.....things became obvious.

Over the past decade, I have created myself a new hunting knife each year, always using the materials and techniques that I had the most questions about at the time....the knowledge gained from using what I produced have been invaluable! When everything throughout the process is done correctly for the given materials, Mosaics and San-Mai constructed blade are ever bit as usable and durable as mono-steel blades produced of the same base materials. Likewise, if the knifemaker uses what they produce, very often a given flaw reveals itself when you look back through the procedures you used to create that blade......which equates to the Bladesmith gaining a much greater insight into how the techniques used to produce the blade, manifest themselves in the usability of the finished product(s).
It all boils down to understanding the materials involved, and ensuring your technique is correct for those given materials. If those things are done correctly, the blade will always be as strong and usable as the "lowest common denominator" (steel type) used in the blade.
More times than not, a simply lack of insight or experience is what makes the difference....not long ago I had an individual visit my shop, and he brought along one of his first random damascus blades......he was so excited and proud because he had produced a damascus blade. Immediately I saw problems....the outward appearance of the pattern was very "muddy". Which often indicates too much heat/duration during the forge welding process, which leads to element migration and/or decarb. I asked a number of questions about his process, with the answers confirming my suspicions about the welding process. Everything else in the process he described seemed appropriate. Then I asked if I could test his blade via the brass rod.....the edge deflected badly with minimal pressure, even though the edge was rather thick, and it stayed there, very much like a piece of mild steel would have. I felt kinda bad that I had more or less burst his bubble about that particular blade, but I think it opened up his thought process that there is much more to it than making pieces of steel "stick" together. I'm not at all trying to make it overly technical, or say that it's unachievable....just that a certain level of understanding and a certain thought process is required for each given process to achieve the best results possible.

[Mike Turner]

Very well put Ed, your always good with words. I always find it difficult to express my thoughts and knowledge into typing, it is easier for me to show them than it is to type it out so they can understand.

[Gary Mulkey]

Thanks for the replies. I appreciate you sharing some of your experience & expertise. I can relate to Mike's comment as I often think my communication skills are better first hand than they are through a key board. However since hammer-ins and shop tours are infrequent, your sharing on threads like this always help to shorten the learning curve.

Thanks