Originally Posted by Drew Hause
It is important to understand the difference in pattern welded blades (which is the process shown), and pattern welded barrels.

Both start with a 'lopin' - thin layers of iron and steel....

The start of the video pretty much does show a 'lopin' being twisted into a 'rod'. The twisting machine is often a modified plumber's pipe threader. The process may have similarities in that, even on a knife blade, the pattern weld needs to be ground into to reveal the pattern.