Fun with SLO: Under Doors: Special Treatment!

Winter is coming (along with gravel, sand and salt), to beat the crap out of your car.

Today I'm working on a special area, under the doors on the side of the ridge visible to a person who happens to have been run over in the parking lot.

For those who have never looked under there, there is a one inch tall metal ridge on the frame, which you are supposed to slip into the groove on your cheap jack in case of a flat, and you want to risk being run over by a transport while changing it yourself.

This area is important and vulnerable, because this is where all the salt, sand and stones are being blasted by your front wheel (especially when you are spinning on gravel etc.

The original car doesn't get much protection from the factory here. There is just a small strip of window calk running along the underside under the paint job, which does a poor job of sealing the crack there between two sheets of spot-welded steel.

Not only is the join and the ridge a prime spot for rust and moisture, its being hit by thousands of little stones and crap everytime you go fishing.

So its worthwhile to do this right, once the 'armor' of that factory paint starts chipping and cracking.

On my 14 yr old beast, the paint has been chipped all over the place, and rust has begun bubbling it in various patches under there, as well as the side.

This job will have 4 steps, all important:

(1) Removing all previous paint, calk, and rust flakes with a wirebrush wheel.

(2) coating the rusty surface with a rust treatment to freeze it dead.

(3) painting over that with a coat of carpaint/rustpaint.

(4) adding a protective layer of ashphalt undercoating.

Here are the basic tools:

http://www.qzoka.com/images/61pt8fspemrx96nuiz.jpg

This THREE LAYER build, will hopefully give the area a fresh start, protect it from bouncing stones, and extend its life another 5 to 10 years.

The side of the car should be protected from the start.

If you use some newspaper and tape, you will be able to get a nice clean paint-line at the end of it all.

http://www.qzoka.com/images/rt7mxt6zw0ayduku8j7.jpg

I made the mistake of using packing tape I had lying around. Don't do this, it makes extra work because the solvents in these spraypaints/coatings melts both the cellophane backing and the glue, and must then be scraped off.

Probably wide masking tape (even two layers) will be adequate to protect the side and keep it clean.

If you're a bit clumsy like me, with the wirebrush and drill, you may bounce over the edge onto the side regularly, so pay attention to the direction of the drill (mine is reversable) and the angle at which you buff off the old paint and rust.

Another thing: I jacked up the car at both ends on the side, to give me lots of room to work under there. Don't skip this step, and use stands and blocks, because its hard enough working upside down, and you'll be on your back lying on the ground for an hour or so.

When you strip all the paint off, you'll discover that even in places where there was no apparent rust, rust was working away under the paint, and there will be spots and discoloured patches showing where it was going to explode a few weeks after you lazily painted it without stripping.

Its these rusty patches that the next step will effectively treat. This stuff converts the rust into an actual hardened primer-surface that is semi-pernanent. The result will be a 'freezing' of the rusting process for a prolonged period, so that this job will last.

After you spray with the 'rust converter', the rusty areas will turn a dark gray/black, indicating they have been 'fixed' and frozen.

After this 'primer-coat' dries, the next two steps follow a 'normal' painting routine.

Here's a look at the underside after the first coat of black gloss rust-paint which has been sprayed overtop the 'rust-converter' after it has dried.

http://www.qzoka.com/images/qni1ej2nnka8uh55dx7.jpg

After this too has dried (at least 20 minutes for each layer/coat) You can spray on the ashphalt undercoat:

Here is what the underside looks like after an ashphalt layer has been applied to the back half (driver's side):

http://www.qzoka.com/images/1ut4fuwh91djdsecuja.jpg

Notice it now has a duller appearance.

But this softer rubbery layer will never completely dry: That is good, because it acts as a kind of cushion for stones and sand bouncing off it at 60 mph.

Lets look at the newspaper again:

http://www.qzoka.com/images/vfvsmj7z1kld71wlfn1n.jpg

Its worth noting that the $300 lower back tattoo was probably paid for through acting sessions in some internet video. ....yikes...

Here's an update with some more photos to help get this job done right:

Photo 1: large areas will APPEAR not to need stripping and sanding down to the metal. But this is a deception, something like the fact that only the tip of an iceberg shows above water:
http://www.qzoka.com/images/jfeao2shlomjwcyzmceq.jpg

Other small patches may appear like this below, and one might be tempted to just wirebrush away the loose paint flakes and rust, and start painting:

http://www.qzoka.com/images/cnz89cbwop2btxg8wjgv.jpg


This sanded down area reveals more of what's really going on under the paint. In reality, the constant bombardment of stones weakens the paint and lets air under it, causing a creeping spotty surface-rust over the entire area:


http://www.qzoka.com/images/byepycbt5j3mektgcd2d.jpg

You might be tricked into thinking you've sanded deep enough, because two layers here look very similar, the layer with the main color stripped off, and the "down to the metal" surface. Here's a closeup. The key difference is the lighter area should be shiney silver and reflective:

http://www.qzoka.com/images/rh0icrny863zvqem6icc.jpg

Once you get down to the metal on both the rusty and non-rusty areas, you can spray on the "rust converter" treatment: This will darken the previously rusty areas (now a dull lightgray), and give a contrastier look like this below:


http://www.qzoka.com/images/waqiqotrt9numsjmvyvq.jpg


After successfully stripping down to metal and coating with rust converter, you're ready to paint a few layers (primer + color) and add the shock-absorbing ashphalt undercoating as a final dressing.

Now you can cruise over those dirt roads on the way to the cottage with confidence and peace of mind.

After my unfortunate experience with the packing tape and newspaper, I found an easier solution.

I found a roll of wide masking tape, and then located a strip of aluminium about 3 feet long, used to cover the edge of a linoleum floor. I ran the masking tape down the edge of this, to hold it on the 'edge' where the car stops being horizontal and starts being a vertical door/side.

This gives a nice straight line for the black undercoatings, which contrast against the red. I am doing a three foot section at a time for the final painting. Its easy once you've finished sanding and have cleaned off all the dust with a rag from the sides and bottom (I'm working outside while its still warm and sunny).

Your final result should look something like this:



http://www.qzoka.com/images/1ut4fuwh91djdsecuja.jpg



Indoors you will probably want to control dust a lot better especially if you intend to paint indoors too.