My beloved 1971 Plymouth Satellite Sebring is a veteran of the rust belt; it was pretty ugly underneath. After seeing POR-15 paint used on the TMC giveaway cars, I decided that would be the best thing to use on the bottom of my Satellite. It is one very, very tough paint; it cures like plastic due to humidity rather than dry like regular paint. However, this project was more expensive and harder than I had anticipated; the total cost of POR-15 chemicals was about $200 and it took me most of four weekends.
The POR-15 people fill orders very promptly and their accessories in the back of the catalog are very reasonably priced; their number is 1-800-457-6715. To avoid confusion; note that both the company and the paint are called POR-15. Also note that Chassiscoat black and Blackcoat are different things.
A word on safety; you MUST use goggles and gloves! POR-Strip burns your skin and cured POR-15 paint won't dissolve in anything that won't dissolve you first. I used 3 work lights for illumination and they ended up with POR-15 all over them forever. I used 2 fans to blow air under the car. The silver and black POR-15 seemed to produce no annoying fumes, while the clear I used on the giveaway car irritated my eyes badly. The instructions indicate that it is way to toxic for me to try spraying, so I brushed it on.
1. To begin, I needed to clean the underside; first with POR-15's MarineClean (easy) and then strip off the old paint, undercoating, and other junk with POR-Strip. The weather was typical for the summer here- near 100F and 100% humidity. The POR-Strip works and evaporates MUCH faster than the instructions say- about 1 minute is enough to soften the paint and undercoating, while after the recommended 15 minutes the solvent has evaporated and the paint is completely hard again.
The POR-Strip works extremely well, but when it drips on skin it really hurts- it burns like hot grease (but doesn't leave a scar) and attacks most plastics instantly. Don't wear a good watch and protect your skin by wearing gloves with cuffs. Keep water handy for neutralizing POR-Strip. I had problems with my enclosed goggles fogging up from the inside (despite the anti-fog spray) and drops of POR-Strip fogged the plastic permanently on the outside. I did small areas at a time and neutralized them with water and a sponge.
After trying POR-15's Metal-Ready (to help prep metal surfaces for painting) on the axle housing, I found it very hard to completely wash off and so decided not to use it on the bottom of the car; the surface was clean and looked rough enough for POR-15 to stick well.
This step took most of my weekend. I left the car to dry for a week.
2. After the car was completely dry, I used silver POR-15 and painted the bottom from the firewall back. I found that with the 100F heat and 100% humidity it started curing and becoming very sticky very fast; it went on thick enough out of the 1 qt. can that I had to use POR-15 Solvent (the ONLY thing I'd use to thin this paint) to thin it enough to finish the job. It doesn't take much solvent to thin the paint a lot. It was very hard to see with the goggles fogged up, but the reflectivity of the silver color helped visibility quite a bit. When it was done, it looked great, but I had paint drips all over me and I was a gooey, sticky mess with various pieces of junk (including an extension cord) glued to my head. Much of the paint was essentially cured by the time I reached the end (~4 hours).
[Loretta's note: This first coat was a real dozy! I knew Kevin was attached to the Satellite, but I had not expected that to become permanent! As the day progressed, he asked me to check on him, as he was slowly getting more and more sticky and feared he would be fly-papered in under the car. Even though he had a change of gloves, his fingers would glue together. When he reached up to adjust his foggy goggles, his gloves would stick to his forehead. By the time he was finished, he looked like a cross between Pan (with the leaves and twigs sticking out of his hair) and the Tin Man from Oz with his silver face, hair, arms, etc. I laid down a layer of old towels on the bathroom floor and got out the mineral spirits and scissors and went to work. Two hours later the floor was strewn with silver clumps of hair and Kevin was fairly well "restored".]
3. The next weekend, I went back and tried to vacuum up all the junk and debris under the car so I wouldn't glue myself to them again. Then I wet sanded the coat as directed; that took about ~2 hours for a cursory job (it is very hard- like sanding glass). Later, when I broke some POR-15 off, it seemed that the various coats bonded to each other very well even when not sanded very well. I ordered more POR-15, but forgot to specify the color. It arrived in less than 5 days and the POR-15 people sent gloss black POR-15, which was fine; I could easily see where I was painting. This POR-15 was thicker, so I thinned it and used most of a quart to cover the bottom. As soon as I finished, I went back and put swatches of fiberglass cloth over a few small holes. The POR-15 was very sticky by then and the cloth stuck solidly in place. I then put another coat over the cloth and saturated it to patch the hole. Between the goggles fogging up and the light absorbing qualities of the black paint, visibility was poor. But again, when done, the glossy black coat looked good.
[Loretta's note: This time I suggested that Kevin use Vaseline in his hair to prevent the mess I had last time. This was a dismal failure. Not only did he have POR-15 in his hair, but a nasty coat of Vaseline. I had heard that it would come out with Wisk detergent, but I was misinformed. Again to the scissors! The black paint came off his skin with the mineral spirits and the Vaseline eventually did wash out....]
4. For the next coat a week later, I got a disposable shower cap and forgot the Vaseline and got safety glasses with side shields rather than goggles so they wouldn't fog up. I wet sanded everything again, spending another ~2 hours of hard work. I now had 1 qt of POR-15 Blackcoat (gloss black) and 1 qt of POR-15 ChassisCoat Black (dull black). I had to dilute the Blackcoat a little with the POR-15 Solvent and then started painting the glossy black Blackcoat atop the glossy black POR-15. It was really hard to tell how well I was covering it, and it took another ~4 hours and used about half of the quart.
[Loretta's note: We have it down to an art now! The cleanup was just a minor bit of peeling crud off Kevin's arms and wiping him down with mineral spirits. He had sloshed some paint in his lap so these jeans turned into statuary and were trashed. Don't plan to reuse any brushes, containers or maybe even clothes that are involved with this project!]
5. The next day, I wet sanded again, and then, to help me see what I was doing, lightly fogged the bottom with grey primer; just enough to see that it was there and to help me get the ChassisCoat (dull) black on. It looks glossy when wet, and trying to distinguish glossy black on glossy black is very hard. In general, contrasting colors are the way to go if possible. This used more than half of the quart.
When I was done, the dull black looked nice and should (better!) last a long, long time. However, I think that I may try Eastwood's Corroless when I do the front suspension... they say it doesn't have to be top coated and stands higher temperatures.
Recommendations:
1- ABSOLUTELY use stripping/chemical gloves, antifog goggles or safety glasses, a shower cap, and good ventilation. Natural bristle brushes seemed to work much better than synthetics.
2- Avoid hot, humid weather (very hard to do around here).
3- Two coats of POR-15 might be overkill; it goes on thick, roughly 1 qt./coat. A single topcoat of ChassisCoat black or Blackcoat may be sufficient, but two POR-15 base coats and two topcoats are recommended by POR-15. Don't plan on an open can staying good very long, even with refrigeration.
4- Avoid having to sand by putting another coat down before the previous coat is fully cured. Sanding POR-15 is very hard - perhaps sanding between coats is not absolutely necessary?
5- Use contrasting colors between coats if possible to see what your doing. Maybe the bottom of a car should be a bright color (silver?) rather than black so it's easier to see while working down there.
6- Be on very good terms with your wife so she'll help get you out of a sticky mess and help free you from cured POR-15.