M116A3 Build

[lfhoward]

Dave, Sharon and Twisted,

Thanks for your recommendations for the propane tank. Safety is my first priority too, and even though it looks great in photos, it is a 33 year old tank after all.

Manchester Tanks like this were built for permanent installation in RV’s and are ASME certified, which is a lifetime certification. The tank should be kept in good working order to remain viable, but its certification never expires. The typical home grill 20 lb cylinders and the swappable horizontal tanks that you find under big RV’s are DOT certified. These are the ones that expire after 10 years and you have to get it recertified or buy a new one.

This is not to say I’m going to fill it up and run. I’m definitely taking this to the propane place down in South Philly where they can change out the old valves and install the new regulator and make sure everything is ship shape. Based on conversations I’ve had with the seller, I don’t think there will be any issues.

[lfhoward]

The awning room is awesome!

We can imagine our god daughters or visiting friends camping in this. It’s 8 feet long so long enough for 2 sleeping bags (or cots) with walking space between.





Also large enough for the two of us to hang out in during a rain storm.

[featherliteCT1]

Assuming it is water proof, you just about doubled the size of your trailer. Nice!

[lfhoward]

Assuming it is water proof, you just about doubled the size of your trailer. Nice!

Thanks! It’s made out of a heavy oilcloth fabric. We expect it’s nice and waterproof. There’s a 50% chance of rain tomorrow so we’re going to test it out.

Here are a couple more photos.

[S. Heisley]

Looks Great! Love the last pic, above.

[noseoil]

Nice one! Should make a nice rainy-day shelter.

[twisted lines]

Nice one! Should make a nice rainy-day shelter.

I Haven't got the darn thing unloaded yet.
But if I make one I think that might just work for me 2.

[lfhoward]

The rainy day shelter lived up to its name. It worked great. The next day we hung the walls on a line and it dried off well, so we could fold it up and stow it in the trailer. It fits nicely in one of the side compartments.

The awning itself was easy to put away also, and it traveled well on the way home attached to the camper. The zippers on the bag stayed in place. The awning bag did bounce around a little as the wind caught it on the highway, but no damage whatsoever. Seems like a good awning solution.

We will probably use the awning every time we camp, but the room I can see is using sometimes depending on the weather forecast and who we have camping with us. We really like it!

Twisted Lines— wow, that’s a heavy duty sewing machine! I bet you’d be able to turn out an awning room with that in no time flat.

[lfhoward]

The new to me propane tank arrived from Missouri while we were out camping. Here are some photos after I got it unboxed today:

The new tank hardware came along with it, which saves me from having to buy it separately.


This is the tank's data plate.


It was built in 1986, and has outer dimensions of 6" in diameter and 29.75" in length.

[lfhoward]

The UK to US adapter came today from McMaster-Carr. It has a female NPT 1/4” for hooking up the heater to the rest of the system. So here is what I am thinking I need. Those of you with Propex heaters installed please advise.

Working backwards from the Propex heater to the tank... (X means I have it). If your brain works the other way around, just read up from the bottom of the list.

X Propex 1600 1/4” female BSPT
X 1/4” male BSPT to 1/4” Female NPT straight adaptor
1/4” 90° NPT elbow with male flared end pointing down
1/4” copper tube, flared. This goes through the floor and the length of the trailer
1/4” Male flared adapter to 3/8” male NPT
X 2 stage Marshall regulator, 3/8” female NPT outlet, 1/4” female NPT inlet
1/4” Male NPT adapter to Male POL
tee adapter for Coleman stove hose, Female to Male POL
X Tank Outlet Valve (Female POL)

Here is an alternative list that uses hose instead of copper pipe.

X Propex 1600 1/4” female BSPT
X 1/4” male BSPT to 1/4” Female NPT straight adaptor
1/4” 90° NPT elbow with 1/4” female NPT pointing down
1/4” male NPT copper pipe, 4” long, to male NPT. This goes through the floor.
1/4” 90° female NPT elbow adapter to 3/8” male NPT flared
3/8” female NPT hose, to 3/8” male NPT
X 2 stage Marshall regulator, 3/8” female NPT outlet, 1/4” female NPT inlet
1/4” Male NPT adapter to Male POL
tee adapter for Coleman stove hose, Female to Male POL
X Tank Outlet Valve (Female POL)

Not sure which is the best way to go, or if I’m getting too complicated or am missing something. Of course all connections would be wrapped in yellow propane spec Teflon tape to seal them.

Please help me out so I can order what I need.

[lfhoward]

Today I tackled getting the old valves off of the propane tank. It was quite a job.

Here's how things sat at the beginning. I have the new hardware lined up with where it will go.


Old hardware removed. I used some big wrenches and some serious leverage, especially for the fill & vapor ports. Although there was no propane in the tank, the inside still smells like mercaptan.


I am wondering how I should clean up these threads. They are not damaged, but there was some residue that looks like red locktite on them from the factory.


I will be using Blue Monster teflon tape rated for propane when I install the new hardware, with a minimum of 3 wraps around the threads.

I want to clean the tank up and repaint it before putting the new hardware on. I'm thinking Rustoleum primer then gloss enamel, white. I'll keep the old valves installed during painting to protect the threads, and I'll cover the data plates and warning labels with painters tape to protect them.

I have an Amazon cart ready to press go, with the following propane-related items to connect the Propex with the tank:
- Rustoleum clean metal primer
- Rustoleum gloss white protective enamel
- Blue Monster Teflon Tape for all the fittings and connections
- 90 degree 1/4 pipe to 1/4 flare elbow for coming out of the Propex's UK-US adapter fitting and pointing down
- 1/4 flare nuts for copper tube
- 10 feet of 1/4 copper tube rated for gas (I have a flaring tool already.)
- 1/4" stainless & rubber pipe clamps to hold the copper tube in place under the trailer
- 1/4 flare to 3/8 pipe adapter which will connect the copper tube to the regulator
- 1/4, 3-way tee adapter, for between the regulator and the existing POL adapter, which fits the tank
- 1/4 to 1"-20 male Coleman cylinder adapter & cap for the tee
- 12 foot 1"-20 extension hose for Coleman stove
- 650 degree rated RTV silicone to seal the holes in the floor around the Propex exhaust, intake & gas pipes

Here is a map of how they will go together:

Hi Res version here: https://i.postimg.cc/T25RKVRx/Trailer-Propane-Diagram.png

Am I missing anything?

(I know I need to get intake and exhaust pipes and ductwork from VanCafe for the Propex itself.)

[lfhoward]

Today I had a few spare minutes so I worked on cleaning out the old PTFE tape from the tank’s threads. It’s pretty dirty inside the tank. There is a black residue. Should I try to clean this out somehow?


After I got clean threads, I made a mock up of what the tank will look like with new hardware on it. Pretty excited!

[lfhoward]

Today I introduced the tank to its new home, and it was very happy about that.

Holding the tank up in place while also taking a photo is challenging!


But the length and height of the tank are perfect for this location, just in front of the passengers side wheel. It is convenient to the kitchen, where a removable hose will go to my Coleman stove. It will also be easy to fill and to turn on and off the main valve from here.


My plan B was behind the axle in a longitudinal orientation. This would be slightly better for weight balance (tank is 35 lbs; 50 lbs full), but not better enough to justify how hard it would be to access and use.


Here is where the tank will hopefully go on the side, in front of the wheel. None of the existing beams match up with where the tank's mounting feet need to be.


I could fabricate brackets using steel angle, like I did for the spare tire holder. The L brackets would have to be bolted to the top of the 1/8" thick chassis frame, and extend outward 15.5" below the floor. They could bolt to the inside of the trailer edge, which has a 1" inward-facing overhang. The metal there is only about 1/16" thick though. Would it support the weight of the tank? Alternately, I could try to get 60" lengths of bracket under there so it could bolt to both frame rails, but logistically I don't think I could get it to slide in.


Lastly, I did some measuring of the floor behind the passengers side wheel. This is where the holes will need to be drilled for the Propex Heater's intake, exhaust pipe, and gas line. I'm hoping all of those will fit behind the mud flap. I haven't cross referenced my measurements with the Propex unit yet, but will get to that.

[lfhoward]

I measured the dimensions of the Propex and it will fit nicely in that rear cubby. In order to keep the exhaust and intake and gas pipes behind the mud flap, the unit would need to be mounted in such a way that the warm air duct will need to double back 180° within a 1-foot space. Since I don’t have an air duct yet, is this bend reasonable? I am hoping to get the sound insulated duct, which I know is less bendy than the stock one.



Alternately, facing the other direction, the gas and intake could go through the floor in front of the mud flap and the exhaust behind. However, I was just thinking that in front of the mud flap gets blasted with water and debris and might be more likely to leak while driving on the highway. I ordered some high temperature 650° F resistant RTV to seal around the pipes in any event.

Another quick question (after the duct bending question above): What do you do about floor insulation? Do you remove all insulation between the unit and the floor, or just remove some around the exhaust pipe? I have a metal floor with foam gym mats as my insulating layer. Not hard to remove, but without it I do get condensation on the metal when it’s cold outside.

[lfhoward]

Getting closer to being able to put the gas line together and fire up the Propex heater for the first time!



I’m still waiting on a couple of parts to show up.

After that I’ll connect everything together with RectorSeal Tplus2 pipe sealer with PTFE. I should be able to test fire the Propex out on my back deck using my grill cylinder as a gas source. Fingers crossed that everything works right. Remember it was a $100 broken heater from EBay that I got. I checked it out as far as I can on my workbench and, after fixing where the fan rubbed on the interior housing, it seems to want to run fine. We have a working fan, spinning airflow sensor, working gas flow solenoid, and strong spark from the igniter. What I haven’t been able to test up to now is the flame sensor, which would allow it to continue running. Because it doesn’t sense any heat (no propane so far), it turns itself off after two ignition cycles. Hopefully it will ignite and run strong.