Thanks. I had not seen the post about heat treatment, but I have now. I managed to get google to translate for me and I think I got most of it (by a combination of my prior knowledge, googles less than perfect translation and guessing :-) ) really interesting read. I have thought about making a comparison of my "ancient knowledge" methods and my modern metallurgy methods at some point too. I find it very useful to know the modern approach, but as I wrote, if you don't have an oven to give you the exact temperature, it is also very useful to know the oldfashioned ways of doing it.