I have done the undersides of cars several ways rotissorie, jack stands, fork lift, ceiling hoist.
What you are doing, you should get 2 or 3 pair of 3 or 4 TON heavy duty jack stands that have some height to them. Jack the car up and support it well. If your going real high, do a little at the front then at the back.
Go buy some (2 or 3)cheap garage florescent lights and bulbs (with the shatter tubes). Lay them under the car.
Now get on your creeper and get under there with a Cup wire brush and a cheap electric grinder. Have at it. You will need some smaller wire brushes that look like tooth brushes for the small areas. a good solid scraper (not the razor blade style) works well too.
After you get the loose stuff off, use LOTS of old rags and plenty of Paint Wax and Grease remover. Buy the good stuff and not the cheaper generic, The name brand stuff is stronger. Go over the under side of the car several times, with several new rags, until your rag stays clean. You will use a LOT of rags. Go cut up the old tee shirts. POR 15 says not to use solvent based cleaners, they want you to use their water based cleaner. I did it their way, and not their way. As long as the solvents are removed and it is dry, there is no problems using a solvent. Water based cleaner will not get your under side as clean as a GOOD solvent based wax and grease remover. Just back wipe with a dry clean rag on your final clean up. Let the work air dry overnight before applying the POR 15.
I would suggest using a brush on the under side when applying the POR 15. I have sprayed it. POR 15 is thick. They say you can reduce it with their reducer. I dont, I like the coverage and thickness. POR 15 will not spray through a gun with less than a 1.7 tip. Dig out the old JGA primer gun and crank it to 45 PSI. It sprays like a HIGH build primer. Again, due to the overspray and doing it upside down I suggest using a brush, it flows out nice and looks good with a brush.
Remember that any hardware, nuts bolts ect that get POR 15 on will be cemented together. It is NEXT to impossiable to remove it when dry. Tape up the threads, bolts, cables, and anything else.
Hope that helps
Ryan
