Time for a Switch (Post # 50)

Now that the engine is in Arizona, the body in Tennessee, and the interior in Massachusetts, I can resume work on the various sub-assemblies such as the electrical system and its components.  The Alfatross came with six toggle switches.  Electrical appliances in those days were minimal:

1. Headlights and running lights
2. Dash and interior lights
3. Heater fan
4. Windshield wipers
5. Driving and fog lights
6. Electric fuel pump switch?

The Alfatross' six toggle switches were mounted "upside down"  beneath the dash.

The dashboard layout for one of the Alfatross' brethren shows only four toggle switches, with one of them operating the electric fuel pump.  

The switches themselves are a study in the evolution of automotive electrical engineering. Compared to today's solid-state, "no user serviceable parts inside" electrical switches and appliances these switches are prehistoric art. When I removed them from the dash I was surprised to see that their internal workings were completely exposed.  No attempt was made to shield the contacts from the elements or accidental short-circuiting.  But they are rugged in spite of each switch being made up of no less than 23 individual parts! They were deceptively simple-looking and fairly easy to disassemble (the toggles needed cleaning up and refinishing), but fiendishly difficult to reassemble.  It took hours for Jeff and I to figure out how to reassemble the first one, but only minutes for the rest.

An assembled switch.  All of the toggle switches
are open-sided and unprotected, like this one.
Even after 60 years they work perfectly.

Is it a switch or an example of industrial art?  Counting the
rivets and fasteners, there are at least 23 parts per switch!

Comparing the Alfatross' circuits and appliances with the electrical schematic in the repair manual for 1900C Super Sprints, revealed some important differences. The manual shows that one of the toggle switches activates the "auxiliary heater."  Being a race car with only basic creature comforts, The Alfatross had a simple heater and small electric fan, but no auxiliary heater. So what did that switch operate? I think the switch dedicated to that circuit now controls the driving and fog lights on either side of the central vertical front grill, but I will have to compare it with the actual wiring harness to be sure.  

Electrical schematic for the 1900C Super Sprint, the chassis modified by Zagato.  41 is the heater switch.  38 is the windshield wipers.  54 is the aux heater/driving and fog lights.  8 is the dash and interior lights.  9 is the headlights and running lights.

This list, along with the schematic drawings above, identifies all the electrical appliances in The Alfatross and provides hints to their location.

Another surprise gleaned from the repair manual schematic was the presence of an engine compartment light, "portalampada" on the list and 46 in the schematic. No. 47 is listed as the switch for the light, but it seems to be in the engine compartment rather than on the dash.  Perhaps it was a mercury switch.  The existence of this light was a complete mystery to me until I took the time to closely examine the list and schematic. A large, round hole in the aluminum plate that holds the Alfatross' fuse box to the firewall may have been for this light, but I still don't know exactly what it looked like.  

Can anyone out there in the Blogosphere give me a clue?  

   

The arrow points to what I think is the engine compartment light.  I found this image on the Internet and do not know which 1900 Z it is, but it is the only one I have ever seen that had a light under the hood.  The Alfatross has the same mounting plate on the firewall for the square fuse box to the right of the light, and a hole where the light should be, but no light.

Real? Or Really Real? (Post # 49)

With respect to Historically Important Automobiles there is a lot of talk about "authenticity" and "originality."  These are surprisingly tricky words.  I prefer to consider the concepts involved rather than the words, which don't have precise meanings.   

We're trying to keep The Alfatross original but there are a lot of areas where that is clearly impossible.  I think we can all agree that not having the original spark plugs is not too big a disappointment.  Ditto the tires, headlight bulbs, the oil in the crankcase, the gas in the tank, the air in the tires.  At the other end of the spectrum it wouldn't be asking too much for the car to have original paint, exterior trim, interior, engine, wheels, tool kit, and other similarly fundamental items.

Then there's all the bits and pieces in between that are iffy . . . .  

After almost 60 years most of the rubber grommets, seals, weather stripping, and gaskets have given up the ghost.  Of course you can't find replacements at your local NAPA parts supplier.  After 60 years even most stocks of rubber "new old parts" are no longer usable.  Face it: with the possible exception of weather stripping you're going to have to make your own rubber parts. 

Yes, there are a lot of rubber pars in a car, and a lot of different types of rubber to do very different jobs.  Most of it has a a very limited life span compared to metals and even plastics.

Fortunately, molding and casting are not new skills that I have to acquire.  There's a lot of that in archaeology, particularly with objects found in the sea. In warm, tropical waters iron decays rapidly. As it does so a chemical reaction occurs which causes minerals dissolved in seawater to precipitate on the surface of the object forming an encrustation.  Sometimes relatively small objects literally dissolve inside the encrustation, but not before creating a perfect natural mold.      

All you have to do is break the encrustation apart, clean out the black sludge that is all that is left of the original iron object, dry it, put it back together, and inject the cavity with an epoxy resin.  After letting the epoxy set you carefully clean the encrustation off the epoxy cast to reveal a perfect replica of the original object.  

These "artifacts" from a ship that sank in the Turks & Caicos Islands about 500 years ago are actually resin casts made from cavities inside natural molds of calcareous deposits that formed around the original artifacts.  The detail preserved in these natural molds is astonishing.

Here's where the real vs. really real dilemma pops up.  Are those epoxy casts not "real"?  The original object is a black, stinking paste. You could pour it into a jar and save it because it's "really real", but why?  Compare the "really real" jar of sludge with the epoxy cast.  The cast is so perfect that it often includes the first layer of rust that formed on the object when it fell into the sea.  It is far more faithful and authentic to the original object than other iron objects from the same site that dissolve inside their encrustations--but it isn't "real" according to the dictionary.  

The rocks on top of Sapodilla Hill in the Turks & Caicos Islands are covered with inscriptions featuring names, dates, ships, flags, and even buildings dating back as far as 1767.  We made molds and casts of many of them.to preserve the information they contain.   One of these rocks is the original.  The other is a cast.  Which is which?  

We do the same thing on land sites to record ancient inscriptions in stone. We make RTV rubber molds of the inscriptions in the field, then cast them in plaster reinforced with a polymer resin.  The casts are then more durable than the original stone.  We discovered that if you spray them with a thin water-based color coat and let it settle, details emerge that were never visible before.  But the inscription casts are not "real"--they are better than real!  

Back to The Alfatross and its rubber parts.  So molding and casting is no big deal--but there's a catch. Synthetic rubber parts come in all sorts of different compounds: hard, soft, oil-resistant, photo-sensitive, elastic, stiff, foamy, solid--you name it, the variety is endless. So one compound does not fit all.  
The compound has to match the job's requirements.

And that's not the only complication.  The original parts usually can't serve and the "positive" from which you can make a "negative" mold for the casting of the final part because after 60 years they are wrinkled, cracked, swollen, shrunken, or otherwise no longer faithful to the original part.  So you have to make a replica positive that you then use to make the negative mold from which you can a rubber positive.  It's a long, tedious process that's worth while when you are making multiple replica parts, but very inefficient for just one!

What happens to original parts over time and exposure to solvents and the environment.  All these parts are the same.  Only the second from right retains its shape and dimensions.

So I have a lot to learn, and it's going to take another post or several to explain what I've learned so far though a series of experiments.  One thing is clear already: if you can find a reliable source for decent rubber parts, BUY THEM!  Don't try to make them yourself unless there is no alternative!