the bottome of my car is in good shape. theres no rust through or pitting (thanks to a layer of grease and oil) there is some powdery rust in the shock tower and in a few other places. most of the floor boards are still shinny black. SAND BLASTING is out of the question. what would be the best way to go about cleaning and repainting and whay would be the choice of paint? Por 15 over the rusty spots then DP90 over everthing? thanks Dave

Did mine with a 4" side grinder with wire brush. Get a real good respirator and go to it. I used POR15 gloss on the frame and simi-gloss on the undercarriage. Applied it with brush, rollers, & sponge brushes. Sets up like it was sprayed on.
Nice.

POR15 when exposed to the elements will breakdown if not painted-something to keep in mind

Armed with Full coveralls.. and a wide varitiy of scrapers, wire brushes, 4 in wire wheel on a grinder... and 3-m scotch pads... the diry parts done.. Then it's a full cover up to brush on the Por-15... Remember when it get's on you the floor the driveway ect. .there's where it will be staying for a looooooog time..
As for break down ??? the only thing I know or have experience is , if exposed to DIRECT UV ( sun-light) it turns a milky haze hue and not the shinny of sim-shinny finish. ( I am under the impresson it protective quality has not deminished !)

cleaned mine with e-z off oven cleaner. works grate. I bought a case at the dollar store.

Has anyone ever tried a power washer?

I own a body shop and I am restorng a 67 Big Block El Camino. I put mine on a hoist and used a good pressure waher to the underneath. Pul any plugs out of the sheetmetal as in the cowl area. I washed under it for over two hours and cleaned every opening I could find. i.e. rockers and cowl. It came out very clean. The oven cleaner is an excellent idea but it will take paint off.

I jacked mine up using the frame rail under the door and jack stands, also left the jack in place. I used casterols degreaser (gallon jug) & spray bottle. I hooked up to the hot water and bought a cheap spray gun at Norhtern. Hooked it to my compressor and hot water. Presoaked underside w/ degreaser let it sit a bit . I had excellent results. Hope to spray the underside w/ urethane black when temps. warm up

I did the oven cleaner thing - it worked great. Then coated with por 15 and painted. Make sure the oven cleaner gets completely removed and let it nuetralize for a while. Por-15 does not like any contamination - trust me on this one. One note: Por-15 can be really messy painting under the car if you dont have a lift.