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

Steering Column Tear-down

Decided to blow the steering column apart since I needed to get the floor mounting plate off and trace for a seal. It was fairly straightforward and actually a little simpler than the one in my Duster. 'Course, someone's been inside already and messed up the steering wheel and horn mechanism.



So what's it take to disassemble one? Not much. After removing the horn pad (which was taped on and missing parts under the pad) I simply removed the wheel nut and used a puller to remove the wheel. One screw and the turn signal lever is out. Remove a snap ring and the main shaft slides out. 3 screws and the switch comes out along with some springs and other miscellaneous parts. Drive the pin out that holds the shift lever in place. There is a set screw that secures the shift tube to the upper assembly. Once all this is off the only thing preventing the shift tube from coming out is the little shift indicator bracket.

The bracket is secured to the tube with two nylon rivets. I presume they used nylon so that in the event of a massive crash it would shear off just as the steering shaft, shift tube, and column housing are designed to collapse - rather than impale you.





I took a punch and pushed the little pins through and the bracket popped off. The nice thing is they should be reuseable.

Reuseable nylon rivet hold the shift pointer bracket to the shift tube. Once the bracket is off the tube will slide out.

A/C Heater controls

Like most stuff on this dash, the A/C Heater controls were really fubered. The vacuum switch was physically broken and my attempts to disassemble and repair it failed. It worked better than before but just didn't operate smoothly enough to reuse. If you've never been inside of one, they're pretty interesting. You can still buy them new from the local parts stores but fortunately I had one from a donor.

A guy in the neighborhood has a '71 Dodge Polara parked next to his house that he plans to demolition derby next summer. It was in pretty good shape and it's a shame, really, to waste a perfectly good car. But since he plans on gutting everything and literally throwing it away he let me salvage parts from it for free. (When he's done destroying it I'm welcome to salvage the drive train). I pulled most of the dash and the heater control has the same vacuum switch as my original. It works very smoothly so I swapped it in.

Swapped in a vacuum switch from donor

The heater blower switch was siezed. There were obvious signs of overheating and when I opened it to see if I could salvage it, it crumbled apart. Most of the wiring in the heater related circuits show signs of too much current flow at some point. I don't know what someone was doing but would explain, in part, why the dash is such a mess. In any case, since the Polara switch is different , I had to replace it with a new one.

Original switch is toast

With some touch-up with a silver paint pen, the A/C Heater controls look like new again and should actually work now.

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.

PCB repair

The gauge cluster has a quaint little printed circuit board on the back. All four pins on mine were loose. Loose pins can cause all kinds of problems with your instruments. The pins are simply swaged on the back of board and it doesn't  take much connecting or disconnecting of the plug to loosen them. Some of the swaging was missing and when I attempted to re-swage others, the metal fell off. As you can see in the pic below there isn't much left.

Not much keeping these PCB pins secure

I lightly media blasted the connections on the board to remove corrosion. Very fine sandpaper would be safer but this way I was able to get into the nooks and crannies and clean the female terminals. A dab of flux applied with a toothpick at the base of each pin followed by some solder re-established a good electrical connection and firmed them up. Glue on the back side added strength.



Solder re-establishes a good electrical connection to the PCB foil traces

I finished assembling the very basic gauge cluster, tested continuity, made sure there were no shorts, and bench tested the fuel gauge. Good to go. I think there are more idiot lights than gauges in these things. Next up: Dash switches and heater control.


By the way, the mechanical voltage limiter on the back of these panels can be a source of gauge trouble too. Mine works but I may replace it. I've made my own solid state version in the past and there are companies that sell electronic versions as well. I ran across this a company called Real Time Engineering that makes one of the most sophisticated ones I've seen. Not cheap but might be worth checking out.

Cluster resto

In the last post I started the cluster resto by stripping the old finish and someone's "paint job" from the bezel with a water based graffiti remover.

I disassembled my original cluster the donor to compare the pieces and select the best parts to build one good one.

Warm, soapy water removed most caked on grime

After washing both lenses to remove some serious dirt and grime I found my clear lens had some light stress cracks in the face. Some knucklehead felt compelled to push on the lens wherever a gauge was located. The donor lens had some deeper scratches.

Cluster lens looking like new

With a little spit, some 2000 grit sandpaper, and a soft buff wheel with plastic rouge I was able to bring the donor lens back to like-new condition. I had to touch up the white paint of one letter on the back side of the lens. You can do it all by hand but the buff wheel makes quick work of it and takes care of flaws that are difficult to remove by hand. You just have to be careful because you can burn the plastic if you apply too much pressure or hold it in one spot too long. I happened to have a Novus 3 part plastic resto kit which I used to do final polishing on the lens by hand.  There are several products for polishing plastic available at your local auto parts store. Some work better than others.

Novus Plastic Polish System


The face of the donor speedo was in slightly better condition than my original so I removed the odometer and tripodometer and transferred them. Remove two small screws and each tumbler drops out as an assembly. I also reset the odometer back to zero. It was a bit like a Rubik's cube but once I figured it out it was easy - much harder to describe. It did involve rotating the tumblers starting on the left. Before someone screams, "You broke the law!" I'll add that here in Washington, due to it's age, speedometer readings are exempt and I have no intention of passing this car off as a low mileage original. I just want to start the clock over when it's reborn.

I synchronized the tripodometer to the odometer so that it advances at the right time. This was easy enough to do by rolling the "tenths" tumbler on the tripodometer by hand without disassembling it. I hooked a drill up to the old speedo cable to test everything.

One freshened-up speedo to go

Stripping a dash

Along with way someone decided to do a color change on this old girl. Car was orginally gold on gold. When they painted the exterior red someone went crazy with black dye or spray paint on the interior. Since the plasticizers in '69-'71 dash pads are known to come to the surface and create a sticky goo you can imagine what happened when they painted it. Yup, we have a black sticky goo covering everything. It's like tar in spots. Flat black spray paint also coats the plastic bezels, including the raised lettering, with a generous amount of overspray on the switches and clear lenses. What a mess!

I picked up a cluster/bezel on ebay that was described as one of the best original speciman's the seller had ever seen - better than most he had seen at car shows. Silly me.

Seller thought this was better than most he'd seen at car shows. Hmmm, really?

Fortunately, UPS broke it in shipping so I got my money back and rather than throw it away  it became a donor for a few select parts.

Anyway, back to stripping. Lacquer thinner does a decent job of dissolving dried spray paint but it can also attack some types of plastic. No problem on the dash pad and useable on the vacuum plated bezel if done carefully but it will cloud clear lenses. Also, at $15+ per gallon it can get expensive. I think I've found something better.  I found a product at Lowes called Motsenbocker's Lift Off 4 - Spray Paint/Graffiti Remover. It's water based, biodegradable, and contains no nasty solvents. While I'm certainly no tree hugger the stuff works surprisingly well and is easy on the nose and skin. It dissolved all the paint right down to the vacuum plating which I wiped off with paper towels after multiple applications. Should work on the dash pad too.