Part 12: The Furnace, or why my projects take forever

On to the tall cabinet, and here's the part all of my projects seem to hit. It took me ten years to restore my Mustang because, among other similar bits of wackiness, I devoted six months to building just the right radio. In this instance, the previous owner had removed the original icebox and enlarged the opening to accommodate a refrigerator. A perfectly serviceable refrigerator, fine shape, but definitely not the right look. I hunted without much luck for a decent original icebox, thinking I'd install one of the Dometic remote compressor refrigeration systems, before I found a small refrigerator with appropriate aesthetics for less money than most of the ratty iceboxes I found were going for. It's about four inches shorter than the refrigerator that's already in there, which, subtracting a half inch for the thickness of a supporting shelf, gave me 3 1/2" of space for something useful.

PO's refrigerator.

Nifty new refrigerator in front of its new home.

Other than the Veritas mantle lamp, there's no provision for heat in the Cardinal. Mantle lamps can do a fine job of heating a small trailer, but most of my winter camping is in places with power, which means I'd be paying for propane but not for electricity. I figured this out years ago in my old Apache, and I stopped firing up the Apache's Hydroflame furnace in favor of hauling an old '80s vintage Pelonis ceramic disc furnace with me. It's a tiny cube, less than 6x6", and pumped out enough heat to cook me out of the larger (and draftier) Apache. Surprisingly, no part of these little heaters get hot enough to ignite even tissue paper, which is a nice safety bonus. The name has since been sold a few times, and the newer versions are inexpensive and unreliable plastic-cased imposters, so I picked up a couple of '80s vintage originals still in the box on eBay. one for exclusive duty in the trailer, the other for knocking around the shop.

Rather than kick the thing around the floor like I did in the Apache, I thought it would be nice to permanently mount it, and maybe drive it with a proper household thermostat. I designed a simple plenum to fit in the tight space available in the space freed up by the new refrigerator.

Design view of the underside of the shelf that the refrigerator will sit on. Squarish cube in the middle is the Pelonis, intake on the left, output on the right.

More 3D printed router templates.

MDO framework for plenum complete, opening for Pelonis marked in the center. In order to reduce the total height, the Pelonis actually fits through an opening in the refrigerator shelf, hanging from a piece of MDO. With the refrigerator out, the Pelonis could even be lifted out if necessary.

Beginning to install the aluminum flashing for the plenum, center mount hole for the Pelonis cut out.

Pelonis apart in order to give it its MDO hat. There's not much to these aside from a fairly robust fan and a heated ceramic plate. I'd originally planned on modifying the Pelonis by wiring a remote-mount extension for the factory thermosensor, but the new design is much simpler and doesn't even require me to cut the power cord.

1/2" MDO hat installed, Pelonis being slid into place for final flashing fitting. I designed it this way for packaging reasons, although the ability to get to it for service or replacement is a nice bonus.

Plenum complete, and furnace assembly ready for mounting.

One feature I really liked in my old Apache was the thermostat-driven Hydroflame furnace. Being able to set a thermostat and maintain a temperature is a huge improvment over the usual high-medium-low settings that many small heaters offer. Pretty much all household thermostats operate on 24vDC, and are really just adjustable thermoswitches that drive a 110v or 220vAC relay that does the actual work in the furnace. I figured I'd just piece the DC power supply and AC relay together myself, but around $10 got me a junction-box mount furnace fan control setup, consisting of just the power supply and relay I wanted in one neat package.

Period NOS thermostat I picked up to control this thing

Furnace mounted in place, ready for grillework, etc.

 

Back in the trailer and complete. I may do a bit of additional trim work around it, but it's a start. Still trying to figure out how much the damaged veneer underneath bothers me- on the one hand, I'd like to preserve as much original fabric as possible, and I'd prefer the look of a well-used, well-loved 60+ year old trailer to a total restoration, and on the other hand OCD. We'll see.