Horizontal propane tanks

[lfhoward]

Hello,

By chance and good luck I was able to pick up a used Propex heater for around $100. I had thought they were out of reach, so was very excited when I won the auction.

My trailer doesn’t have room for any propane tanks on the tongue, so I have been looking into horizontal tanks that can be mounted underneath.

For example:

Here are some options that will fit (all Manchester Tank models):

3.3 gal $470 @ VanCafe
https://www.vancafe.com/253070601D-p/253070601d.htm

5.9 gal $580 @ GoWesty
https://www.gowesty.com/product/lp-tank/4323/lpg-tank-

6.7 gal $599 @ Campervan HQ
https://www.campervan-hq.com/products/rv-propane-tank-6-7-gallon-manchester-model-6811

The first is 6” diameter and the other two are 8” diameter. Prices are better for 10” and 12” diameter tanks but I don’t want to lose the ground clearance. Also, the capacities are actually 80% of what is listed because there has to be room for gaseous propane above the liquid.

All of these seem crazy expensive compared to your normal vertically mounted tank, which can be had for under $100.

Does anyone run an underslung horizontal LPG tank like this? If so, where did you find it? Do you like it and is it convenient to fill up and to use? Do you wish you went with a portable conventional tank instead? Thanks in advance for any insights as I plan my Propex heater setup.

Lauren

 

[lfhoward]

In terms of propane consumption, a Propex HS2000 uses 1 lb every 3 hours (https://faroutride.com/propex-install/), but the heater never runs continuously so a pound of propane would last longer than 3 hours. If we are being generous and put the run time at 20 mins per hour, a pound of propane should last 9 hours.

A 5 gallon propane cylinder for my backyard grill holds 20 lbs of propane. Thus, 1 lb should be equal to about 0.25 gallons, or 4 lbs is approximately 1 gallon.

Practical run times for a Propex on the 3 tanks listed above would be:

Tank Size / pounds / hours of heat @ 20 mins running per hour
3.3 gal / 13.2 lbs / 119 hours (5 days)
5.9 gal / 23.6 lbs / 212 hours (9 days)
6.7 gal / 26.8 lbs / 241 hours (10 days)

Dividing run time by the price gives a measure of how much each costs relative to how long you can heat your trailer without having to break camp to refill. A higher number of hours per dollar would be more bang for your buck.

Tank Size / cost to buy / hours warm per dollar spent
3.3 gal / $470 / 0.253 (15 min per $)
5.9 gal / $580 / 0.366 (22 min per $)
6.7 gal / $599 / 0.402 (24 min per $)

The above lets us compare the tanks to each other, but may not reflect real world usage. For example, if you’re a weekender, the small tank is more than large enough for you and may be the best option for the price. If you’re wanting to maximize boondocking time, one of the other two would do the trick nicely, and would be a more efficient purchase.

In my world though, I’d love to see a lightly used tank like any of these show up on eBay for a fraction of the price. If anyone has one they want to get rid of, send me a PM!

 

[Tony Latham]

Well.... I wouldn't build another teardrop without a Propex heater. So two thumbs up. Make it three.

Could you shift to a smaller tongue box and an 11-pound bottle?

Or just mount it on the end of your current box?


Tony

 

[lfhoward]

Thanks for the suggestion, Tony. The tongue box is actually modded to be a battery box.

Not a lot of room there between the battery box and the surge brake actuator. Parking brake handles overlap the sides of the box, so can’t get any wider.

There’s a bit of weight on the tongue already, so I was hoping to balance it a bit by putting a propane tank behind the axle.

Can a tank like yours fit next to the back door? It would stick out... explode in a rear end collision?

There is a lot of space underneath though.

 

[Tony Latham]

Can a tank like yours fit next to the back door? It would stick out... explode in a rear end collision?

Maybe it would prevent a collision back there? You could paint a big red arrow pointing at it.

My tank is about 9- 1/2" in diameter. As far a CG, it can't weigh more than thirteen pounds.

Tony

 

[Ottsville]

This doesn't solve your balance issue, but if your tongue box is only for batteries and you don't access it all the time, why not just put a bracket right on top of it? A ring that a standard propane bottle can sit in, with a few thumb bolts that go through holes in the bottle base would be enough(with maybe a strap over top to satisfy the nervous nellies). There's a lot to be said for the convenience of a standard bottle, especially on longer trips when you don't want to have to spend time finding some place to get refills and can just stop at a grocery store and swap out your tank.

Or build a mount up from the frame in the rear. Wouldn't be hard to do.

 

[Squigie]

First:
When thinking about mounting location, remember that someone else will be filling this tank. They need easy and safe access. If they have to crawl under the trailer, lay on the ground, or position themselves in front of the purge valve, you may not be able to get it filled. Easy, safe access.
They will also need some place, likely on the tank itself, to clamp a ground cable.

Secondly:
I have had several ASME tanks.
I don't want another one, unless it's attached to a vehicle that I absolutely want for everything else about it.

Unless you know that you will always be able to fill the tank at a good propane supplier that knows what they're doing, I recommend sticking with DOT tanks. They're easier to work with, easier to fill, and easier to get inspected (most places).

My biggest problems with ASME tanks come back to the whole "certified for life" thing. They don't need to be inspected, which means they don't get inspected, which means few people know how to inspect them. And if you do find a place that will do ASME inspections, they almost never restamp them. ...But if they do, it's only if the tank is empty and purged. (Which takes time and costs much more than for DOT tanks.)

And that lack of an updated inspection stamp means that at least 95% of places where you might stop for propane will see the "expired" certification stamp and refuse to fill the tank, only fill it after giving you a hard time and needing you to show them that ASME tanks don't get recertified, hem and haw for 10 minutes before "doing it for you just this once", or claim that they don't know how.
I have even seen many predatory/shady RV centers claim that an ASME tank was "expired" and had to be recertified, for a not-insignificant fee, before they would fill the tank. (Even my grandfather fell for this, with a $75 fee, once; and a $150 fee the second time. They put a generic 'hologram' type sticker on the tank that said "Certified and Inspected" and wrote the date with a paint pen. )

The theory of a permanently mounted tank that can be tucked out of the way and never needs to be inspected is appealing.
And it can work well if you have a good propane supplier that knows ASME tanks, and you'll only be using that supplier and staying close to 'home base' the majority of the time.
But, when out on the road - especially for long trips - ASME tanks are nothing but a headache and feel like a liability.

It's like having an electric car, and having to plan trips based on where charging stations are located; or going back to the '80s and having to plan a trip based on where you could get diesel fuel.

 

[Tony Latham]

The tongue box is actually modded to be a battery box.

Not to send this thread off to the hinterlands, but what are you using all the juice for? Inquiring minds are curious.

Tony

 

[lfhoward]

The tongue box is actually modded to be a battery box.

Not to send this thread off to the hinterlands, but what are you using all the juice for? Inquiring minds are curious.

Tony

Hi Tony, The electricity is to power computers (1000 watt inverter) and recharge GPS units, phones, etc. along with the regular camping items like the fantastic fan, lights, electric blankets, etc. I made the trailer to be able to camp and and also transport equipment & be a field station for my job as a forest ecologist. The original idea was to be able to be off grid for a week before needing a recharge. Later on, I acquired a 160 watt solar panel that keeps the batteries topped off, so I don’t need to plug in to charge them. So, 3 batteries is probably overkill now with solar. When they were new they were 80 AH batteries, so the trailer had 240 AH (120 usable). Batteries don’t hold nearly that much these days.

 

[MtnDon]

In the 23 years that we had a class A or C motorhome we never ran into a single situation where a propane dealer balked at filling the ASME tank, or tried to bilk me with an un-needed certication. Canada to Mexico and almost every state west of the Mississippi. Just lucky? Sort of related though, I have had propane dealers refill a DOT tank that was expired. Happened twice with the same tank, the same summer. When we got back home my local dealer noted that right way.

 

[lfhoward]

Ottsville & Squigie, I appreciate your perspectives too. I asked for your frank opinions and experience. The van conversion websites are all about getting an AMSE tank and not DOT, so it’s good to hear a counterpoint to that.

MtnDon, that is pretty much what I’ve been reading. I’m wondering if the reason propane dealers didn’t have an issue with your AMSE tank had to do with accessibility. If it is visible and easy to get to, maybe it would be less of an issue?

 

[lfhoward]

One way to make a horizontal tank more accessible would be to mount it on the side, forward of the tire. I have approximately 3’x1’ of space there.

Smaller tanks like this WV Vanagon unit (3.3 gal) would fit there.

Of course, re-doing my battery box to hold one good AGM deep cycle might provide room for a DOT cylinder on the tongue.

 

[MtnDon]

MtnDon, that is pretty much what I’ve been reading. I’m wondering if the reason propane dealers didn’t have an issue with your AMSE tank had to do with accessibility. If it is visible and easy to get to, maybe it would be less of an issue?

Could be. On both of the vehicles we had the ASME tank fill was accessed via a hatch/door on the vehicle right side that opened and gave easy access to the filler, the shutoff and whatever else was clustered in that area. We'd drive up to the propane station and they would connect and pump. Considering the numbers of RV's on the road with ASME tanks it is mind boggling to me to think that many people run into trouble refilling. Most motorhomes, other than the smallest van conversions will have ASME, but trailers and slide-in campers will use DOT, most often. Maybe if the ASME is in a trailer that confuses some propane sellers?

FWIW, some of the larger RV ASME tanks are equipped with the necessary pickup and valve to allow refilling DOT portable tanks.

 

[treeview]

I've got one for sale..in Minneapolis though

Such a long shot but if you think the logistics could work let me know

Tom

 

[lfhoward]

My used Propex HS-1600 arrived from EBay!

Instead of having two parallel threads going, please go to by build thread for photos of the unit and some questions I have about making it functional. The seller told me it wouldn’t start, but I think I may have solved it.

Propex in my build thread:
http://www.tnttt.com/viewtopic.php?f=50&t=62581&p=1266150#p1266150

 

[lfhoward]

Update:

I found a lightly used 3.3 gallon Manchester tank from a VW Westfalia camper van in really good condition. I purchased it and it should be here in not too long!

Here is the ad for as long as it stays up:
https://www.thesamba.com/vw/classifieds/detail.php?id=2388098

The little tank should fit nicely under the side of the camper so the fill valve will be easily accessible. I’ll post pictures once it arrives.

 

[MtnDon]

 

[lfhoward]

I thought maybe I'd have more visibility with the folks who have propane setups if I posted this here.

To bring you up to speed, I bought a used but nice 3 gallon Manchester tank from a 1987 VW Westfalia camper van. It's about 30 inches long and 6 inches in diameter. Yesterday 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. Is Rustoleum an appropriate paint for a propane tank? Spray or brush on? Do you think the primer coat is needed since the tank isn't too rusty?

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.)

 

[Tony Latham]

I need to get intake and exhaust pipes and ductwork from VanCafe ...

Looks good to me. You might ask VanCafe if they have the low-decibal exhaust pipe.

Tony

 

[lfhoward]

They have what they call the “stealth kit”, which includes longer exhaust and intake pipes with mufflers, as well as an interior hot air pipe made of a sound deadening material. I’ve watched some YouTubers including Cosmo, who showed it made a big difference. I like quiet.