Stefflus

Thanks :) It's really not that dark, neither the lighting or camera was very good.

I've made a few blades before, but I never got around to getting them done. The past week, however, I was put in a mandatory knifemaking course, since the teacher of the course I was supposed to attend called in sick. Thus I had to make a complete knife. It was real crowdy in the shop, so I forged a blade one night after everyone had gone home. I wasn't too happy with it, it has a hammer mark that is too deep, and the grind is not like I wanted it. I was going for a hollow grind, but because of some unwanted facets I had to hone on a coarse diamond until the edge became all flat. By then the forge was crowded all the time, so no second attempt. Because of this I saved my burl handle stock for later, and went with an ordinary piece of oak for handle. To liven the handle up a bit I ground some powder of pine bark, mixed it to a paste with danish oil, and filled the pores with it. It comes off real dark, and is a nice contrast, methinks. The blade is a piece of an old file laminated into some mild steel. The camera did not bring out the tempering colors. It has been tempered again after final honing, and the mild steel turned out a lustrous gold, while the edge is bronze. The image quality is not exactly benefiting from taking the picture through a glass door.. Sorry about the quality of this picture, I drew it with the mouse. As you can see, I cut off the blank opposite to the shape of the finished knife, and then bend it back. This is because I used the "U" approach to avoid stick welding, and by doing this I get HC in the knife point even after extensive sharpening. Many prefer to draw out the tang first from the end of the blank, I've tried both, but have not landed on a favourite.

I was discussing de-rusting yesterday, and learned that museums use tannin to blacken iron after derusting. I knew about the phenomenon, but I have never heard of it as a deliberate finish. I was somewhat critical about its use if the original finish was some other kind of blueing, burned finish (tar or oil), or just scale from forging. And I made a point that it would be just as good to colour it with a alcohol soluble colorant. But is tannin a historically correct finish?

I would argue that with my low skills a laminated design would provide easier and therefore better heat treating. With my low tech approach, I can never be entirely sure that the temper made an axe that won't break if I use pure HC. Unless it breaks, then I can be sure it wasn't properly tempered. Also I just plain like the old ways.

Okay, that didn't work. Baking soda turned into a charred fluffy entity with a few clear droplets oozing out. I suspect it might have to be dehydrated before use.

Baking soda was mentioned early in this thread. I just assumed that it would decompose at relatively low temperatures like some other carbonates, thus forming caustic soda anyhow, so that using caustic soda would be the same thing, basically. Wikipedia has shown me I was wrong, baking soda does not decompose, and boils at 1633 deg. C. Will be trying that today.

I'm not seeing alot of alternative fluxes in this thread, Except Jason0012 who mentioned Table salt, and Phil Krankowski who debates a number of minerals. I am home on vacation, so I will not be able to order and use borax this following week, therefore I'm gonna try table salt. I'm guessing it only works as a protective layer, although I tried heating the end of some 3x19mm (1/8x3/4") mild steel with a gas torch to red heat, applying Table salt, and it seemed to take some scale with it. Will be trying to weld with it as soon as it stops snowing :angry: The teacher at my smithing course also suggested it. -How many of you have tried? I'm also optimistic about caustic soda, it has a higher melting point, but I'm hopeful it might be a little more aggressive with the scale. Anyone tried? Potassium Hydroxide (caustic potash) might also be a candidate, but I don't have any. Anyone tried? It's easy to sort fluxes by melting temperatures, but the difficulty comes by the eutectics that might occur in contact with scale, or in a mix. By itself I'm sceptical to: -Ground marble, melting point: 825 °C 1517F (aragonite) 1339 °C 2442F (calcite) In the vicinity of melting points, it starts to decompose and forms CaO, which has a melting point of 2572 °C (4662 °F) -Methinks that would hinder welding, unless some eutectics aid it. CaO would be present in wood ash as well. -Sal ammoniac, melting point: 338°C 640F, at which it decomposes to Ammonia and HydroChloric gas. -Unless it enters a eutectic mix??