Rust
Rust[edit]
The Australian R31 Skyline has reasonable rust protection applied to the steel, and some of the body is very well protected by some kind of soft wax product. Other seams in the body are sealed with some kind of sealant that reacts very badly to water. Over time this sealant becomes spongy and holds water against the seams, becoming a rust accelerant, rather than an inhibitor. The Japanese R31 Skylines seem to have been more fortunate in this regard. I suppose many R31s have made it to the age of 15-20 years without falling apart, so Nissan's obviously learned something since the 120Y. Here is the classic R31 Skyline rust under the front quarter panels: (photo courtesy FSTR31)
And again, on a GTS2: (photo courtesy GTS145)
And again: (photo courtesy Sick R31)
The above after some cutting:
However rust can appear anywhere if you're unlucky. Other common places include around the bottom of the windscreen, the A pillars, sedan tail lights, wagon tailgate struts, roof skin, etc. etc. The drain problem with the Australian Skylines may be related to extra steel in the area. According to Wheels Magazine in 1986 "...as a result of the arduous [Nissan Australia] test cycles, the new body/chassis structure was modified and beefed up with some thicker panels and reinforcements." There's a bit of bracing in there which seems to be the main water trap for the area, and I would be interested to find out if the Japanese Skylines have the same panels.
You can check for the drain rust under the quarter panels by taking out the side indicators and peering up inside the guard. Scary stuff. It looks like this:
That is probably a good check to do when buying an R31, as you're not going to be able to remove the guards. I would think that if you could see the firewall lining and loom peering back at you, you should possibly find another car. However you're going to find something on most Australian cars. Here's the same car with the guard off.
If you love the car and want to drive it for a long time to come, you should do something about it, as it's only going to get worse. To state the obvious, you need to remove as much of the rust as you can, stop any further rust occurring, and replace any steel you removed (preferably not with bog). In terms of the age and value of the car, I question whether it would be economic to pay anyone else to repair this, but if you removed all the panels and did the surface preparation yourself, you could probably get away with giving the panel beater only your forearm up to the elbow instead of the whole arm and a leg.
Drain Rust Repair[edit]
Now I'll attempt to fix it at home without welding. I don't have a welder, I'm unsure whether the surfaces could be prepared well enough to make a good weld, and I have zero experience. If I was a good welder, I probably would try that route. Anyway, have a poke around with a screwdriver or whatever and reveal as much of the steel as you can, while removing all of the old seam sealant.
An angle grinder with a wire brush makes things a lot quicker. After you've got bare steel like this, you need to put something on it to keep it from rusting again, like zinc primer or fish oil. I can't say enough about fish oil, it's a miracle substance, it penetrates in everywhere and then dries to form a protective flexible self-healing gel sort of coating. I have used several sorts of rust convertors, and I'm not a big fan, they have little penetrating ability, they'll convert the surface layer, leaving rust fermenting underneath, so you have to go back to bare metal anyway, and then there's no rust to convert. Sometimes they do OK, but I personally wouldn't use them on something that was going to be hidden away and not see the light of day again for a few years. I like waxes, oils, and greases. However YMMV.
While the front is off, there are a lot of other seams revealed that you can get fish oil into, to stop them rusting in future. Here I've undone the bolts on the door hinge, and levered the skin up a bit to get in underneath.
The old angle grinder at work again, this time with a cutoff disc. What looked to be good steel above turned out to have rust extending into the seams, so it all got cut out until it was back to clean steel. All along the way I was injecting fish oil into seams and cracks, and painting bare steel with zinc primer. When you use the angle grinder, have a hose or spray bottle of water handy (Thanks for the tip Tensop.) I set the firewall lining on fire with the stream of sparks when I was cutting these sections out. I used interesting and colourful language. Luckily I had the garden hose next to me. Actually this is another reason why welding is a bit of a worry, there's a lot of flammable or meltable stuff in the area.
I found several old computers on the side of the road, so I took their cases home for the steel. (Again thanks Tensop for the tip.) This steel is a similar thickness to the Skyline steel, it's a bit softer to cut and work, and it doesn't rust easily - I intentionally left offcuts outside to see how they weather. I made cardboard templates, and when satisfied with the size, transferred it to the case and cut them out.
The rivets are stainless steel, which is a lot stronger than aluminium. The rivet tool needs to be tough to cope with these rivets, most cheap rivet tools aren't suitable. I bought several lengths of rivet to suit different depths, sometimes the rivet is holding two skins together, sometimes four. I coated the patches with fish oil just before they went on. I put chassis grease around the rivets, so the drill hole would stay rust free. Some might say that rivets are a bit agricultural, and they may be right, but I figure that as rivets hold a lot of aircraft and racecars together, they should be OK for my Skyline.
The computer case was good too, because of the right angle bends which I needed for these sections. I worked my way along, hammering and riveting. When finished, I degreased the area, then applied two coats of fish oil, and waited for it to dry. It took over a week. This photo is before degreasing:
Finally I was able to apply the stone shield stuff. There are no stones under here, but it's a thick flexible textured surface, still wet in this photo:
Some of the products used:
After the stone shield had dried, it was time for three coats of Nissan Beacon Red, again still wet in this photo:
It came out fairly reasonable, both sides:
Wagon Strut Rust Repair[edit]
Rust Removal from wagon strut mounts: These things don't seem to have been galvanised very well, if indeed that was how they were treated, and rust easily, especially on the exhaust side. Tap the roll pins out with a punch or similar to take the mounts off the strut.
This is one case where I did use rust convertor, dilute phosphoric acid in fact. Phosphoric acid is the basis for most rust convertor products, it changes soluble iron oxide into insoluble iron phosphate. I bathed the mounts in phosphoric acid overnight, checking them occasionally and scraping off converted oxide until I had clean steel. They go in red (oxide) and they come out blue (phosphate). This stuff is pretty strong, I left a washer in there for a couple of days, and when I came back there was just a washer shaped stain on the bottom of the bath. (I use an old porcelain bowl for the acid bath.) It attacks paint too so I don't like using it directly on the car, only on small things I can remove. After the acid bath I used zinc primer, and it turned out like this:
Top coat of Beacon Red, a bit of grease, and back on the car:
Panel Steel Pinhole Rust Repair[edit]
A tiny pinhole on the roof where a bit of rust ate through:
I personally hate bog, and I was able to get away without using it by soldering the hole. Put oil on the hole first, which stops the steel oxidising when heated, and wicks around inside to wet any rust inside. You need a really powerful iron, or the steel will just sink all the heat away.
After the solder is cool, you can shape it down, bearing in mind that lead is pretty nasty stuff, and paint it with touch-up paint or similar. Could also use lead free solder (silver/tin) then not such a health hazard.
Sedan Tail Light Rust Repair[edit]
Anyone?
Compiled by:
Prestagea