I have recently started making Damascus billets and in some of my research ive heard "you have to have compatible metals". I don't really understand what makes two different steels compatible for forge welding. Mainly I'd like to know what I can use out of my scrap pile (since im a farmer with 4 generations worth of scrap). I have tried an old duck foot shovel, ( basically a hoe for plowing ground ) with a stainless saw blade. These haven't really been working and I'm not sure if it's my ability to forge weld or if it's the materials. Thanks.