Inner Fender Repair

Earlier in the spring I had a friend, who owns a powder coat company, sand blast a number of large parts to get them cleaned up and prepped for paint.

Over the years, battery acid completely destroyed the battery tray and ate away at the driver side inner fender where the tray is mounted. Before I could prime the parts with epoxy I needed to replace the missing metal.

The first step was to create a pattern that I could transfer to a new piece of metal. I just used a piece of paper and made reference marks so that the holes that are supposed to be there would end up in the right spot. I traced the pattern into sheet metal and then hammered the edges over a form to create the compound curves. A couple of relief cuts in the corner made things easier. I used a cutoff wheel to remove the cancerous metal as marked.

With trimming, grinding, and several test fits, the piece was ready to weld. Then it was just a matter of recreating the two holes that are supposed to be there. The larger hole is for access to install a J-nut into the smaller one. The battery tray is anchored here with a bolt.

I finished the day out by laying down some epoxy primer to protect a number of large parts until they can be finished. The dash frame has some rust pits to be filled before it's resprayed black.

Topcoating the firewall

Austin and I spent a couple of hours this afternoon during his Christmas break doing some odds and ends. He's a real trooper 'cause this kind of stuff is boring for a kid his age. I handed him some Eastwood Rust Encapsulator and had him topcoat the firewall and underdash area that I had previously treated with a rust converter (for mild surface rust). This will seal it and give it a uniform appearace. We're still cleaning paint out of Austin's hair.



Austin applies Eastwood Rust Encapsulator

 Meanwhile, I removed the e-brake assembly and cable, finished the resto on the AM Radio, and repaired some broken plastic tabs on a couple of the dash bezels.

AM radio ready to go back in

To repair the plastic tabs I'm trying a product I hadn't used before called, Rapid Fix. It's basically a super glue with a powder filler. It works very fast and seems to create a strong repair. We'll see how it holds up but so far I'm favorably impressed. It's similar to another product called Plasti-Fix which I used on my Duster project. I can't say yet which one I like better. You can get a better than website price on the Rapid Fix by shopping around.

In this case I created a dam with tape and then began alternately applying powder and glue to build it up. After it cured I was able to easily grind it to the shape I wanted with a 2" Roloc disc.

Rapid Fix before grinding/shaping

Don't buy a car built on a Monday or a Friday...

They say you shouldn't buy a car a built on a Monday or a Friday. Monday, because workers are hung over from a weekend of imbibing and Friday's because they can't wait to get out of there to start drinking. I don't know what day of the week this old girl was assembled. I'll have to figure it out sometime. But, I have to wonder if it was a Monday or a Friday. More on that in a minute.

When these cars were built they weren't fully dipped or primed like today's cars. A lot of metal is exposed and the upper part of the firewall behind the dash is no exception. Several weeks ago I treated the surface rust on the inside of the firewall with some Duro Extend rust converter. It did a good job of converting the rust to a black iron phosphate. Normally I would have used some Ospho but I had the Extend sitting around so I thought I'd try it.

I planned on topcoating it for a uniform look and extra protection with some Eastwood Rust Encapsulator. (I'm also a big fan of Zero Rust which is very similar). But there were a couple of things to take care of first.

The cardboard and fiberglass firewall insulation was in tough shape when I removed it. I really don't want to put it back in. There are some modern heat/sound insulation materials available today that are a better option. I've used RAAMmat BXT in the past which is like Dynamat but a lot less expensive and every bit as good or better. Problem is, large black nylon push pins secure the insulation to the firewall. Eliminating it would leave dimpled holes. So, I hammer and dollied the dimples flat and welded the holes shut.

Welded up the dash insulation holes

The other issue involved the area of the firewall where the Heater/AC box is mounted. Some "hack" has been into the box before which doesn't help matters, but that's another story. The fiberglass is full of cracks around the mounting points and two of the lower mounting studs were broken off. Fortunately, they were still there. Upon closer inspection I found the firewall wasn't flat where it should be.

Seems when they were spot welding this piece in at the factory, somebody jumped the gun on the trigger before it was in the correct position. A few of the welds on the seam missed the toe board altogether. They must have pushed the end into place to finish it off and just let it go.



Firewall pooches out at this seam.

With the globs of seam sealer removed on the inside you can see the dramatic difference. This defect not only made sealing the box to the firewall difficult but put damaging stress on the fiberglass when it was tightened down.

Pooched wall is hard on fiberglass heater box

Another curious find were two small tears in the toe board just below the seam in the same area. They were partially obscured with seam sealer but one hole had daylight shining through it. I'm quite certain it left the factory this way and didn't occur later. I welded them up.

I was afraid I was going to have to drill out several spot welds in order to push the panel in where it belongs. But since it wasn't really welded at all I only had to separate one weld then use a chisel and small sledge in the corner bend to persuade the metal back. A little hammer/dolly work, a couple of spot welds, and the area is reasonably flat as it should be. The heater box will be much happier. I know I am. Built on a Monday or Friday? Maybe. But fast and sloppy back then was the name of the game.

Nice and flat now. The notch in the seam is factory. This is the area they missed with the welder.

Electrifying rust removal

I'm familiar with electrolysis for rust removal but have never actually tried it. So, after pulling the super-crusty HP manifolds from the engine I decided to give it a try. If you have a media blast cabinet (which I do) I think you'll find blasting faster and, in some case, more effective than electrolysis but it does have it's place.

Your electrodes consist of the part to be cleaned (cathode) and a sacrificial anode. In this case I used pieces of steel rebar because it's really cheap. Sheets of metal or scap iron will work too. Stainless steel is not recommended (though it stays cleaner and lasts longer) because it creates toxic waste. You'll also need a power supply. In this case I used a battery charger set at 35 amps. Smaller chargers in the 2-6 amp range will work too but might take a little longer to do the job.

The final piece of the puzzle is the water solution. You'll need sodium carbonate - more commonly known as Washing Soda. Baking soda is sodium bicarbonate and is similar but the not same. Since washing soda can be hard to find you can do what I did and go to a pool/spa supply and pick up a package of 100% sodium carbonate for a few dollars. By the way, you can also make it by placing baking soda on a tray in your oven and baking it at 300 degrees for an hour or so to drive away water and CO2 molecules - converting it to washing soda. At temperatures above 300^o  Fahrenheit (149^o Celsius), baking soda decomposes into sodium carbonate, water, and carbon dioxide - but I digress. 1/3 to 1/2 cup of soda for every 5 gallons of water will do. More soda will not make the process work better.




My basic setup

 

Electrolysis is s line of sight process so your sacrificial electrodes should be placed around the part to be de-rusted. They need to be tied together electrically. You can tie them altogether with copper wire. I tack welded a coat hanger to the ends which not only joins them electrically but helped hold them in place. Your container can be anything large enough to accomodate your part(s). Plastic is recommended for a host of reasons. Make sure the part to be cleaned does not touch your electrodes or you'll create a short which will kill the process and possibly your charger.

Connect the POSITIVE cable to your electrode grid and the NEGATIVE cable to the part to be cleaned. Get the cables reversed and you'll get the opposite result than the one intended: your part will be sacrificed and your electrodes will be derusted. The nice thing about the process is you can't overdo it. You could leave your part in for days with no ill effect.



Now, once everything is properly connected, turn the charger on and you'll see champagne style bubbles form off the surface of electrodes and your piece. A few hours later (or overnight) and theoretically your rust will be removed leaving behind an inert black oxide coating. This film can be removed under fresh water with the help of a wire brush.







I got fair results on an exhaust manifold which had a lot of surface rust. The manifold was too big to fit in my 5 gal. bucket so I had to turn it. When I turned it I decided to add sodium hydroxide (lye) to the mix to see if it would work any better. I think it improved the process considerably BUT you're creating a nastier and potentially more dangerous water solution by doing do. Drano Kitchen Crystals is a good source of lye. Proceed at your own risk, however. If you burn your skin, put an eye out, or otherwise poison yourself, you're on your own.

Derusting a battery tray brace worked really well. In the picture below, the right end of the manifold spent time in the soda/lye solution, while the left side got soda only.





"De-rusted" battery tray brace and exhaust manifold





SAFETY PRECAUTIONS: Use rubber gloves and face protection - especially if you introduce lye to the mix. The process also gives off hydrogen gas (that's what those bubbles are) so do it outside or in a well ventilated area. Hydrogen gas is potentially explosive. The wash soda only solution can safely be poured on your lawn or down the drain without any environmental concern.

For more detailed information on the process with additional links click here.