I barely used 5cc of the tube on my first application of OC 2.0 on my car. It says to destroy after single use. Would I not be able to use it again on a different car? seems like a major waste of product.
No, it can be used until its gone on multiple vehicles. Just make sure it's free of air inside the tube. Store in the house out of the elements.
after I was done I simply wrapped the end of the tube with electrical tape to help keep it sealed. What signs should I look for of it being beyond the point of use?
I would reinstall the shipping tip. When the tube gets cloudy air has been introduced. But that doesn't happen that often, it seems that application is where you will notice most of the problems. Hazing, not flashing, or staying tacky.
Keep the Syringe in the UP position with the applicator tip at the 6 oclock position and the plunger at the 12oclock position. Keep the little Blue tip in the the applicator tip. Get as much air as possible out of the cylinder As long as it is clear and in a liquid state, it should be good to go. Dan F