The Studeblogger

Sunday, October 18, 2009

Lark Heater rebuild, Part 2: Refurbishment

With the heater system removed from the car and disassembled, you can start refurbishing the parts that are salvageable and hunting down the replaceable parts (hoses, clips, cables, etc.).

 Here's yet another great reason to get a copy of your Shop and Parts manuals on CD-ROM: you can print out individual pages. The one above shows all the bits that go into the '62 - '63 Climatizer system. Almost all of the larger parts (fan case, diverter box) are available used if yours are missing or damaged beyond repair; almost all of the small parts (cables and cable clips, fan cage, molded hoses, water valve, heater core, defroster duct hoses) are available new from Studebaker International or other Stude vendors.

A lot of my larger parts were rusty thanks to the leaky core and valve dripping antifreeze all over them for - well, probably years. I decided that this would be a good time to try using electrolytic rust removal, a process that uses electricity instead of blasting or wire-wheeling to get rid of the corrosion on steel  parts. You can read about the process in detail at The Stovebolt Forum, but here's the process in a nutshell: Find a plastic container, fill it with water, and add a tablespoon of Arm & Hammer baking soda for every gallon. Stick a piece of rebar or other sacrificial iron or steel stock in the water to use as an electrode; your rusty part becomes the anode. Submerge your rusty part in the water and connect your battery charger's negative cable to it; connect the positive cable to the electrode bar and switch it on - the more amps, the better. (One SDC Forum member told me confidentially that he'd derusted an entire engine block this way using a stainless tank and a welding power supply. I do not recommend or endorse this method!) Don't submerge your clamps, or they'll get eaten away! I decided to try this on the blower fan, which had surface rust all over it. Here's how it looked just after switching on the juice:

And here's how it looked about four hours later:

This nasty muck is all the rust that's been electrically removed from your part! Don't worry, it's not toxic, just fugly. After about a day, here's what came out of the soup:

It may not look very pretty, but it's no longer rusty :) That black coating is what's left behind by the process in place of the rust; a swipe with a kitchen Scotchbrite pad removes it and exposes shiny metal that can be primed and painted. I used this method on all of the blower case parts. The top of the case that holds the core started out like this:


...and came out like this. One of the side benefits of the process is that it loosens most paint, so it comes right off. I buffed the clean metal with a Nyalox wheel from Divine Brothers.

After the buff, the pieces were so pretty I was almost tempted to clearcoat them and leave them this way :) But everything got a nice coat of Rustoleum primer and gloss black and were set aside to cure.

While all this cleaning and painting was going on, I was ordering parts from SASCO and SI: hoses, a new blower motor, and other small but essential parts. Once they arrived, it was time to start reassembling the cleaned and painted parts. To attach the blower motor to the case, place the gasket over the long machine screws installed in the motor case and place the case over the threads. New locknuts on the blower side hold it all together; I put a little Loctite on the threads to make sure the blower vibration doesn't loosen the assembly. Make sure you orient the motor so that the power leads exit toward the blower case outlet.

Next, push the fan cage onto the motor shaft. Use care here; you don't want to bend the fan off-center, so don't push on the rim - push only on the hub. A socket on an extension handle can be used to get the hub down on the the shaft.

Leave about 3/16" of shaft exposed for the spring clip that goes on top to keep the fan from leaving the shaft at speed. New ones are round versus rectangular originals, but functionally they're the same. Use the socket to slide it tight against the fan hub.

After the blower fan is reinstalled, you can reassemble the blower case. Since a previous owner had used the wrong screws, I re-tapped the holes and installed the correct screws to hold the case together. Set the assembly aside; it's time to work on the air diverter box.

As mentioned in the previous installment, the fiberboard diverter flaps inside the box that control fresh air flow and heater/defroster mode had long ago lost the rubber sheets stapled to them. This meant I would have to disassemble the box, since there is no way to access both flaps from the outside. I also decided to use something a little more durable than rubber sheet to re-surface them.

Chances are you will need to perform this operation as well, so you'll need to remove the old-school rivets that hold the formed cardboard top onto the molded plastic bottom. It's that old-time thermo-plastic with the fibers impregnated to give it strength. But it's still soft plastic, and I didn't want to drill out the rivets because they'd spin and enlarge the rivet holes, so I used needle-nose pliers to bend up the tabs and remove them.

Once the top's off, the flappers can be removed and re-surfaced. I got two 8.5 x 11" sheets of black felt from Michael's; one with self-adhesive backing and the other plain, and laminated them together to obtain the correct thickness.

The residue left on the rectangular piece indicated that the original covering wrapped around the end of the piece opposite the hinge rod. After cutting the felt sheet to the proper size, I glued it to the hardboard using a liberal coating of E-6000 cement. I did the same to the round flapper, applying the felt to both sides.

Note that there is a small washer at the top of the shaft on the rectangular flapper. Don't lose this! It needs to be on the shaft when you reinstall it so that the flapper will move smoothly and stay at the correct height.

As mentioned before, the top of the box is made of pressed cardboard; mine looked a bit tatty. On the advice of a poster on the SDC Forum, I brushed it with a mixture of carpenter's glue and water. Not only did this visually rejuvenate the aged cardboard, it also stiffened it and made it water-resistant (just in case the heater ever decides to leak again). The results were really spectacular, and after the glue wash dried it was time to re-assemble the halves of the box.

Start by locating the diverter flaps in their holes in the bottom of the box. Note that the arm on the round flapper is pointing down. After the flappers are located, the top can go back on.

I tried a couple of things to fasten the top back on; at first I used plastic pop-rivets but they didn't grip - they loosened right up. Then I tried an aluminum rivet, but it took too much force to tighten and I was afraid of cracking the plastic. I wound up using #6 machine screws with lock-nuts to secure the unit; not correct, but not damaging. And, if I ever need to open it up again, it'll be easy to do.

Now that the blower and diverter box are refurbed and reassembled, we're ready to re-install them in the car. Stay tuned for Part 3!

Labels: , , ,


Post a Comment

Links to this post:

Create a Link

<< Home