that page is a load of total, complete bobbins (the cast iron fever bit) I would trust that no more for foundation advice than I would trust me for knitting advice.
If you dis-credit yourself on one piece of advice information / , how can you expect people to trust you on others ?
(John, @ Johns Hammer emporium, perveyor of some of the finest cast iron (well over 20,000 of em, still industry standard best) Massey hammers... )) -
(im not saying they are bad hammers, but tell me how many of them have been double shifted, tool steel forging for 50 years and still going strong....