Kitchen lab work 101. This may simply be a process issue but I need a reality check.
Over 1 month ago I placed various oil samples in sealed canning jars in a freezer. They thickened as expected during the first day and from there remained stable for weeks. No apparent change in viscosity. (swirl test) But just yesterday I checked again and now I notice changes. The castrol HD30 is essentially frozen. Zero movement inverted 10 seconds. Mobil drive clean dino 10W30 is close behind. Both flowed, albeit slowly, just two weeks ago. Mobil1 TS 10W30, SS 0W40, Ams 0W30, Havoline 5W30 appeared thicker, relative to their xW rating. I checked freezer temp and it still fluctuates ~-2 to -5*f during the day. Containers are sealed tightly. No signs of moisture inside.
Is this normal or is a control out of whack? Given equal temperatures, would a total lack of agitation for two weeks have an effect on their viscosity?
David
Over 1 month ago I placed various oil samples in sealed canning jars in a freezer. They thickened as expected during the first day and from there remained stable for weeks. No apparent change in viscosity. (swirl test) But just yesterday I checked again and now I notice changes. The castrol HD30 is essentially frozen. Zero movement inverted 10 seconds. Mobil drive clean dino 10W30 is close behind. Both flowed, albeit slowly, just two weeks ago. Mobil1 TS 10W30, SS 0W40, Ams 0W30, Havoline 5W30 appeared thicker, relative to their xW rating. I checked freezer temp and it still fluctuates ~-2 to -5*f during the day. Containers are sealed tightly. No signs of moisture inside.
Is this normal or is a control out of whack? Given equal temperatures, would a total lack of agitation for two weeks have an effect on their viscosity?
David