Getting to the bottom of the floors, part two: The cover up

Alright, so the metal has been prepped using delicious acetone and is now bearing it's tooth.

In case you thought the scenario involving aluminum powder mixing up with the grinder leavings was far-fetched, here's what I used to scrub the surfaces:

Now, to the paint. POR-15 is one of the better flowing paints I've used. It does a really good job of getting into surface irregularities, but there are some extreme irregularities to account for with some of the welds I'm trying to seal.  Because of that, I want a little more flow than usual and will need to thin the paint out a bit.

POR-15 cures in reaction with ambient humidity.  This is one reason that you need to ensure your surface is totally dry before applying- the moisture causes the paint that is in contact to cure faster than the rest of the paint, which traps the moisture in and corrodes the metal.  For this same reason, you have to be careful about which thinner you use.  Of course, POR-15 promises pain, regret, and misery to anyone foolish enough to use anything other than their proprietary thinner, but I'm a risk taker (or there's not any suppliers open on the weekend within driving distance. Your pick).  

When looking at alternative thinners, we have to immediately rule out anything with alcohol or other solvents that absorb moisture.  This means aromatic solvents are going to be what we're after.  I grabbed the highest quality xylene available at 8:30PM on a weekend (read: what they had at Home Depot), which I'm hoping will treat me right.  Picking and choosing which instructions I'll obey, I'll only be thinning the paint by 5% at the most.

Yeah, right. I'm not measuring anything! I'm doing this by eye, so it'll probably be more like 15%, if not more.  Not a big deal, though, since this is a nook-and-cranny filler.  The actual paint is going to be a different beast altogether.

This is why they tell you to put plastic wrap between the lid and the can after opening (and so you can open it again).

And this is what you do when the plastic wrap doesn't work.

Dispense and thin the paint, brush it where it needs to crawl, and get ready for the next part.  It's like paper mache, but with glass and isocyanates. 

The tube is "POR Paste", i.e., the same damn thing that's in the can, but thicker and more expensive per ounce.  The white mat is fine strand fiberglass, and I'm not going to mince words; it's a pain in the dick to use. 

I used the paste because I first used this method when I didn't have the actual paint.  In the interest of reducing need to buy additional products, I've tried the same general approach on the driver side, though with the canned paint.  It's looking like it'll be fine, if not a little easier.

When you lay your POR strips, don't bother fussing around at getting them laid just right.  You'll find them a lot more compliant after about 30 minutes to an hour, which is when the paint has started to cure.  Wait until the mass has a plasticy, clay-like texture, and firmly press it in place to evacuate air pockets and ensure complete contact with the surface the god awful mess is applied to. 

The idea is for the glass to act as a substrate for the POR, which is pretty damn tough stuff once it's dried.  After it's all cured, lay down your full final coat(s), and you're set.  For the underside of the vehicle?  Do the same thing, but upside down.