Bob
The billets were made of 13 layers of 1080 and 15N20. Both are around .8 carbon and seemed to have very similar heating and expansion rates. That made the forge welding process easier. The stack were mig welded together and were around 1.25 wide, 4" long, and 1.5" high.
We heated the billets in coal forges. After a good soak to come up to heat they were brushed and fluxed. Then when they reached welding heat they were welded with a gentle pass through Bob's Big Blue air hammer. They welded up nicely. The hammer had good control and we used it to it's full capacity.
We had a mix of experienced smiths and learners. Even guys who had never welded before got their billets welded. There were cases of not using enough flux or hitting too hard and delaminating the weld, but most were quickly overcome. Any project like this is always a major learning experience! So we had "learning experiences" that taught us what happens when you get the billet too hot, and what happens when you work it too cold!
I did get a billet welded up to 117 layers. Now I need to decide what I am going to make with it! It was a fun day! Thanks to Bob and his family for hosting the Hammer-in!
