fiber prep, Fiber Science, Fleeces, washing

Alkaline Scouring: Washing with Fels-Naptha soap

Quick update on the cormo project and washing with alkaline soap.


I did the first of several test washes on my cormo fleece.


a gorgeous 16-18 micron cormo fleece;  12-14 crimps per inch,  3.5-4 staple,  yellow staining on the last 1/2 inch or so. Moderately greasy, but the lanolin is nice and glossy with no hard areas. If you hold it in your hand, it immediately softens and starts to shed    Light dirt line, some minor felting at tips from being coated. No noticeable vm at all. Nice clean edge on cut side of fleece.

First washing test:
Fels-naptha laundry bar and lock by lock washing. It takes about 30 seconds to wash a lock. The pH of the wash water varies based on the soap concentration, so I decided to make as thick a solution as my pH meter can read. Reading came back as pH 9.6. This is right at the edge of when the pH adversely effects the bonds that keep the wool fibers stable.  Temperature is important here.  I kept the water temperature at 125-130F though the lock rarely reaches that temp because it is being rubbed on the bar of soap.   The soap has low-medium suds and dissolves easily into water.

To wash, I held the lock by the cut end, dipped the lock in hottest water from the tap (130F), then pressed the lock against the bar and rubbed in line with the staple until the soap came through the top. Flipped lock around and did the same for the cut end. Then I submerged the lock and pushed the soap along the fiber- cut end to tip, flipped then tip to cut end until all of the dirt was gone. Rinsed in 135-130F water and dipped in a final hot rinse in a vinegar and water solution which was probably unneeded. I’m a belt and suspenders kind of person.

Afterwards, I set the lock on a dish towel, pressed out the excess water and left to air dry.

Observations: The lock is completely clean of dirt. Small amount of lanolin left behind.  Locks shrank just over 1/4 of an inch.  The final washed locks were well formed until I started messing with them to see how they would draft.

They draft smoothly from the tip with some light grabbiness at the cut end. The fiber has a nice luster and feels soft and airy. I will try less time with the soap next time because I could see that this could easily dry out the fiber.


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