On Dec 18, 2008, at 9:58 AM, David Skolnik wrote: > .like, what the solids are in VS, Best I can tell, from evaporating some, is that the residue of VSP is silicone oil and conditioner (the fabric softener used in laundry). I also evaporated some fabric softener, and it seemed like the residue, plus some oil, matched pretty well. > and how that would make it more of a sizing solution than a > shrinking agent. With wool felt, water is the agent, both for "shrinking" and "sizing." Shrinking is essentially making a denser felt, interweaving the fibers more tightly. If the felt is being compressed or agitated while wet, it will "shrink" (especially noticeable when a wool sweater is put in a washing machine, but also with pinned action centers). "Sizing" in the sense of making it "larger again" is a matter of making a less dense felt. If you add water and have no compression or agitation, the fibers will tend to unlock somewhat from one another, especially if they are densely held together and there is a kind of pent up pressure, resulting in a less dense felt that takes up more volume. In either case, the water and the individual fibers are interacting identically, with the fibers swelling and their scales standing up a bit. The conditioner is essentially only affecting electrostatic charge, best I can figure out (they are usually "cationic"). I don't know if this has an affect on felting or not. My guess is that it doesn't affect felting much if at all, but I certainly could be wrong there. It does reduce friction, but because of surface electric charge, not as a lubricant. Regards, Fred Sturm University of New Mexico fssturm at unm.edu
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