I am curious as to if someone could tell me the difference between 3M Controltac and 3M Scotchcal? I understand Controltac to be pressure activated, and Scotchal to be not be. If someone could elaborate that would be great. Also, any input on the difference between 180Cv3 and 170Cv3 would be greatly appreciated. I currently use 180Cv3, but wondering about 170Cv3 for flat wraps. Thanks for your help!