I applied sharkhide to my camper about 2 years after it was born. I buffed it out and got a reasonable shin. I then followed the sharkhide directions. I have had this coat for about 3 years now. One thing I noticed......below the door on the aluminum our naked legs, rubbing the aluminum, have created a particular shade(patina). I assume salt from the body has had a reaction. Either way the aluminum is not fully protected, or the finish has thinned. I will strip it out buff it out and reapply. I suggest to use a sprayer. I would consider borrowing one if I was unwilling to buy one. If it is a warm day, the liquid will take a set and leave stroke lines, so be careful. I think I will do mine this winter when it is in the mid 50s. A slow cure seem to flow well and stoke line will disappear, if you don't use a sprayer. I would spray at least two coats, you will like 3 better. You must concern yourself about dust and such as that. It strips easy with mineral spirits. I removed my bumper, tail lights, license plate holder. To do it w/o concern, tape your windows, and your front bump cover, and your roof vent. After this work, two coats seems easy.
Steve