Recently replaced the wicks in my Singer 241-12 Industrial machine using 100% braided nylon rope cord. The machine was made in 1941 and the original braided cotton wicks were caked with dry gummy oil.
Some of the braided nylon I found has a hollow core. The cord I ended up using had a nylon fiber core similar to the original cotton. It seems to work well and is very inexpensive.
The feed lifting rock crank slide uses a short 1/8" round felt wick. I used braided nylon for that also but may eventually replace it with felt. I found one foot lengths of round felt wick in 1/8, 3/16 and 1/4 inch at http://vintagewireandsupply.com. Mcmaster Carr has them in longer lengths also as someone stated previously.
I have basically disassembled and re-assembled the entire machine for cleaning so I know it well if anyone has questions about servicing the Singer 241.
