Around the World Airstream #6768

[dbj216]

Hi and Happy New Year to you. Cramer will make a maiden voyage in 2020. How about that!

Congratulations on the new Denali diesel. I've read GM has made many improvements and they are winning comparaison tests in the auto magazines. My friend has one and likes it a lot. It sure rides nicer than my Super Duty.

You are making good progress on Cramer.

David

[goransons]

Looks great Joe! Stealing all that furnace work this week!

[66Overlander]

First update of 2020. I have continued to work on the furnace installation, including:

1. Reinstalling the front duct.
2. Finishing and reinstalling a new rear duct to mate up with the original floor duct. As noted previously, the old rear duct hole in the original furnace case has been converted to a cold air return by covering it with a screen.
3. Connecting the furnace wires to power, ground, and the thermostat.
4. Installing the new furnace front cover.
5. Reinstalling the original furnace front cover over the new furnace front cover, which will completely hides the conversion, since the modified duct will be hidden inside a (yet to be reinstalled) cabinet.
6. Reinstalling the original thermostat in a closet wall.
7. Connecting the thermostat wires.

I ran out of daylight before I could test the propane connections for leaks, turn on the 12V power and propane to the furnace, and give it a test. I hope to do all of that tomorrow.

[dbj216]

Good luck on your furnace test. Remember, the New Year's celebratory fireworks are over.

David

[66Overlander]

Quick Update: SUCCESS!!!!

Got a late start today. Leak tested the propane lines and found no leaks. The furnace fired up on the first try. Let it run for three off-on thermostat cycles for about an hour total run time to prove the old thermostat was compatible with the new furnace and to burn off that "new furnace smell". Next time I am there with fresh lungs I'll fire up the furnace again to see if the burn-off smell is completely gone or if it's still there a little bit.

I started straightening the exterior furnace aluminum perimeter trim, much of which was somewhat bent up. I then clecoed it into place in preparation for test fitting the aluminum chimney so that it can be modified to allow the new furnace to intake cold air and exhaust hot air.

Then time ran out for the day. I'll be back at it tomorrow or the next day.

[NevadaGeo]

I have a general question. Are there furnaces that run on electric also, since most of us have generators but not usually an endless supply of propane. Doesn’t make since to have to go out and find propane when we have a generator running already.

[dbj216]

Always a good feeling when something works as it is supposed to after all that planning and hard work. Congratulations on a successful "blast off".

David

[66Overlander]

Originally Posted by NevadaGeo

I have a general question. Are there furnaces that run on electric also, since most of us have generators but not usually an endless supply of propane. Doesn’t make since to have to go out and find propane when we have a generator running already.

I have replied to you via private message to keep my thread from going "off topic". Take a look at that message and let me know if you have any other questions.

[66Overlander]

Today I made a custom drip cap to divert any rainwater that comes down between the furnace chimney and trailer skin to either side of the new furnace cold air intake and exhaust port.

I then re-riveted the original perimeter aluminum trim and new drip cap in place thru a layer of butyl tape to seal it.

I temporarily hung both the original bent up chimney as well as an undamaged chimney in place to test their fit. I found I will need to make some small adapter brackets to be able to secure the chimney in place, but did not have the right tools with me, work ended for the day.

I think I have a solid plan on how I will modify the chimney to allow the furnace to more easily take in cold air and exhaust hot air, but that step will wait until the chimney can be secured in place to determine the exact locations for the modifications.

[dbj216]

Jiminy chimney! The original one sure is beat up. The other one looks functional. That was quite a carbuncle hung on the side of the trailer back then.

The drip cap is a good idea.

David

[66Overlander]

Thanks for staying with me thru these sometimes minor updates. I try to look at things positively, even if my daily progress is less than hoped, as was the case today. All progress is good. Making these posts makes it feel like I am getting closer to the finish line.

Today I made and installed new furnace standoff brackets from some aluminum angle stock because the original standoffs bent from the chimney cover were too wimpy and too short to allow the chimney to sit parallel to the trailer skin.

The attachment method mimics original, however. At the top, the chimney slides over the original external louver assembly that was located outside the original furnace exhaust (that has been closed off). At the bottom, two screws secure it to the metal lip that was around the original cold air intake (also closed off). I added U-nuts on the standoffs so the screws can achieve proper clamping force.

I had hoped to also get the chimney modified to allow the furnace exhaust and cold air intake to breathe today, but quit when I found I did not have the proper size hole saw. I hope to get that done tomorrow, so I can pronounce the furnace "done" and move on to other projects.

[dbj216]

As they say here on the Forums: It takes 10x longer to put the trailer back together than to "gut" it. Your new furnace chimney looks original and looks in great shape. It will be better than Airstream delivered it.

David

[66Overlander]

Mixed results today. I modified and installed the furnace chimney and tested the furnace with it in place.

The Modifications:

1. I cut three holes in the back of the chimney, one for the exhaust, and two for the cold air intake. The rearmost hole is for the exhaust, and allowed the exhaust to hit a curved inner piece of steel to be redirected to the rear. The center hole allows the cold air intake to draw air straight in thru an existing oval shaped opening in the front of the chimney. The front hole allows cold air to be drawn from the area forward of the chimney similar to how the exhaust is directed to the rear of the chimney.
2. I made and installed a steel heat shield/deflector inside the exhaust cavity with a lip at the edge to try to deflect the exhaust away from the trailer skin.

The Test Results:

1. The furnace ran just fine for 20 minutes with no signs of the initial "burn in" smell inside the trailer.
2. The rearward deflected exhaust did initially cause moisture condensation on the cold trailer skin which quickly dissipated and the skin eventually became quite warm to the touch.
3. The chimney itself became very hot near where the exhaust was deflected rearward, but remained cool to the touch a few inches away.

Since I never tested the original furnace, I have no idea if the chimney or skin became hotter in my test than with the original furnace. No doubt both were affected by exhaust heat from the original furnace. My new furnace is only 18k input BTU, while the original furnace was 25k input BTU, but the original exhaust was routed differently. The chimney does have the words " CAUTION - HOT" molded into it.

I am left to contemplate if this is acceptable, or if I need to make further modifications such as:

1. Trying to find an install a thermal insulator between the inner steel diverter and the outside aluminum skin of the chimney.
2. Making the deflector lip larger in an effort to deflect the exhaust further away from the trailer skin. By deflector lip was smaller that the original deflector lip.

Worst case, I could have to cut a hole straight thru the chimney to allow the exhaust to blow straight out from the trailer as designed. I may move to other projects and think about this for a while before making any decisions on further modifications to the chimney.

[66Overlander]

Furnace Chimney . . . Plan B . . . Redo . . . Do Over . . . Try Again . . .

I was not happy with my first attempt that curved the exhaust to the rear because of how hot the chimney got and the the condensation and heat on the trailer skin, so I decided to start over using the original chimney with a "straight out" exhaust. I had a lot of other things taking up a lot of my time lately, so this "redo" project was undertaken slowly, one hour here, two hours there, as time and weather permitted.

For this Plan B, I decided the disassemble and straighten the original bent up chimney, rather than rework the replacement chimney. My two main reasons for this decision were:

1. The chimney is original to the trailer and bears scars that align with scrapes and creases in the trailer skin, most or all of which were likely put there during the Around the World Caravan.
2. It had a flat outer surface what would better align with the end of the exhaust pipe, whereas the replacement chimney had a "bump out" and the exhaust pipe would protrude where the surface curved. I did not think I could make this look right.

I did think that straightening out some of the dents and creases, at least a little bit, was worth the effort and it allowed me to replace the rusty original rivets with aluminum rivets. I tried to lessen the rust stains a little bit, but had to stop when the effort was causing the chimney to take on an unnaturally bright appearance in the affected areas. I did not want a "polished" chimney. It needs to retain a patina that matches the rest of the trailer.

I thought long an hard how to make the pipe extend straight outward. Options I considered included:

1. Attaching the exhaust pipe to the chimney.
2. Attaching the an extended exhaust pipe to the trailer and cut holes in the chimney to fit over the extended pipe.
3. Having a two piece exhaust pipe, with part on the trailer and part on the chimney, likely with a small air gap in between.

In the end, I selected option 2 as the easiest to do and the least likely to cause the chimney to get hot. In fact, when installed, the chimney does not touch the exhaust pipe at all. In a quick 10 or 15 minute furnace test the chimney surface within a half inch of the exhaust port didn't even get warm to the touch.

I did have to cut an oval shaped hole in the back of the chimney so that it could be installed over the fixed exhaust pipe, but you can't really see that hole once the chimney is installed, so it does not matter. I decided to not cut additional holes to allow more direct fresh air intake. The 1" clearance between the trailer skin and back side of the furnace seems to be enough to allow the furnace to intake cold air without issue.

The front hole intersects the existing oval hole in the outer surface of the chimney. The round section is cut just slightly larger than the exhaust pipe diameter. I might estimate a 1/16" to 3/32" clearance. The exhaust pipe extends about 1/16" to 1/8" beyond the outer surface of the chimney.

Overall I am very happy with the final appearance. The modifications are very unobtrusive and to the casual observer they might not even know it is not original.

[dbj216]

Oh how often we vintage trailer enthusiasts say "start over, rework". Happens all the time with me. That heat exhaust sheetmetal sure looks complex compared to modern ones. Combustion air in, combustion air out. It appears you did maintain the original patina that goes with a 61 caravan trailer. I think people will stare at that thing for several minutes trying to figure out how it works. Test it with your CO monitor on just to build confidence in the thing.

David

[66Overlander]

Time for another update. Though I haven't posted in a while, I have worked on Cramer at least a couple of hours most days (often more) since my last post. The trouble is that I am bouncing around a variety of projects and nothing significant has been completed. I have worked on the stove, the fridge, the kitchen cabinet, the water heater, and a few other minor things. Plus I have spent many, many hours over the last few weeks doing internet research about rebuilding stoves and other topics. Today, I'll post about progress on the stove and leave the other topics for another post once I get some better photos to accompany those updates.

As you may recall, back in post #273 on 11-11-2019 I mentioned that I had picked up another stove, a 3-burner Meynell that was only used in 1962 Ohio built 19' and 22' Airstreams. That model is fairly tough to find, as larger Ohio built 1962 Airstreams got a physically larger 4-burner Meynell and California 1962 Airstreams got Princess stoves. Bambis from both pants just got a cooktop without an oven.

Anyway, I knew that both stoves had significant rust issues and I could probably make one good stove between them. Interestingly, there are significant construction differences between the two stoves. My original stove came from early in the 1962 model year and had no oven safety valve. The "donor" stove, which came from a late 1962 19' Globetrotter, has an oven safety valve. There are a lot of other minor differences between the two stoves that are not worth detailing in this post.

In early February I needed to decide which stove "core" to use for the rebuild, so I finally got around to testing the operation of both stoves on propane. On the "donor", everything worked except that the oven safety valve would not allow the main oven burner to light. The range burners worked better than on my original stove and the oven primary and secondary pilots and thermostat valve worked. On my original stove the burners were finicky and would at least require the replacement of some jets. The oven pilot and main burner lit, but there was a propane leak around the control knob shaft of the oven thermostat assembly. Once I discovered the gas leak I didn't bother testing the oven thermostat operation.

Given that the oven thermostat/control valve assemblies were not interchangeable between the two stoves, I decided I had no choice but to rebuild the donor "core" from a safety perspective, though I will end up using some parts from my original stove that were in better condition.

I proceeded to tear the donor stove down. I took all the chrome trim pieces to a local shop to have them re-plated. Hopefully, I'll have them back by the end of March.

I ordered new 1000F oven insulation. I am holding off installing it until I can repaint the "insides" of the stove (the area below the burners) that were pretty rusty. I am waiting for it to get a little warmer before I undertake that task as I will likely repaint the stove outside. I intend to reuse the oven door outer skin without repainting it. Likewise the inside of the oven will not be repainted.

I will likely send out the oven safety valve to have it rebuilt, but have not done so yet. The turn around time is about 2 weeks, so I am not in a hurry.

Well, that's about it for today's update about the stove. The stove likely won't be reassembled until late March or early April, so I may not post about it again for several weeks, but look for some other posts about the other projects I have been working on in the coming days.

[Bubba L]

Joe, progress is progress no matter how little it is. I think the antique stove is an eye catching appliance and to spend time and money to refurbish it is the only way to go. Having the pieces re-chromed will look great. Your progress is going well.

[dbj216]

You are making good progress as there are so many hours in the details. Restoring Cramer is admirable and very difficult. It's like restoring an old 50s Porsche Carrera to concours condition. Not an easy task.

Us "fix it up" guys would pitch the old stove on the way to Camping World and bring home a new one of about the right size. Install it and move on. Easy peasy.

Cramer belongs in the Airstream museum at Jackson Center some day.

David

[66Overlander]

Thanks for the kind comments. Restoring is definietly more time intensive than "renovating". Here is a little more of the recent progress.

I made a bracket and installed the water heater switch in a hidden location inside the bath cabinet below the sink. I needed to do this because I installed an electronic ignition water heater instead of a simple pilot light version. No electric heat element, though. I connected the water heater to 12V and ground and routed the wired under/around the bathtub. I turned the switch on and got the expected error light indicating that the water heater did not ignite, which is correct because the propane is not yet connected.

I also routed the tank monitor display cable from the bed base to the bedroom roof locker. It is hidden behind a piece of vinyl trim that previously hid the propane line from the shelf to the roof locker that supplied the Humphrey gas lamp in the kitchen. I added a piece of modern wire channel below the shelf so that the cable could not be snagged when the center gaucho was turned down into a bed. The original gas line was not covered below the shelf. The cable will be routed into the kitchen roof locker after it is installed as that is where I intend to hide the tank monitor panel. The gas line will not be replaced as I intend to eventually convert the Humphrey lamp to 12V.

Finally, for this set of photos, once the above electrical items were completed, I permanently installed the bed base and kitchen wall.

That's it for tonight. There will be more updates in the coming days.

[57Vintage]

You are to be commended for the attention to detail done to retain the original look while making the necessary changes to make the rig modern enough to use under our current requirements for camping.

Much more thought required than my work in retaining original features, but not hiding all the modern pieces.

Your work and Scott Goransons's are important to maintain the history that precedes us. kudos to both of you