20lb Propane Tank Storage/Mount - Will this work?

[A_Bus_Called_Quest]

Skoolie Fam!
In light of the recent supply shortage on just about everything - including horizontal mount propane tanks - I'm thinking about moving to the standard 20lb BBQ tank.
A) this will be easily replaced or refilled just about anywhere, without having to drive the bus up to the refill station.
I can buy them NOW - and they are way cheaper :biggrin:

No mater what tank I get, horizontal or standard, I want to mount it behind the rear passenger wheel, where the storage compartment is now. My idea is that I can leave the door in-place, and cut out the storage box to accommodate the tank.

My questions:
>How strong does the "cage" need to be to hold the 20lb tank? I want to protect it from tire blow-out, that is probably the most severe impact I could think of besides a collision.

>Could I get away with angle-iron supports on the sides, with an expanded metal bottom? maybe one side completely covered with sheet metal to protect from the tire. (see attached mockup)
I want to make it big enough to eventually add a second tank if needed. I would use one of those trailer-mounted propane tank racks with the threaded rods in the middle to hold the tanks in place (mounted to the 'floor' of the tank-cage)

I've read the tank needs to be hidden by the lowest part of the frame (or as close as possible) to avoid DOT inspection problems - I think I can fit the standard tank with just a little bit of the bottom showing.

I don't have a welder, so thinking I will use bolts to hold everything together. . . My neighbor does have a welding machine so I could probably hire him to help me weld something up if there is no weld-free options here. Just want to be sure everything is safe - this is the only part of the build that could potentially kill us all

 

[musigenesis]

The RVIA guidelines for external propane tanks use an 8X dynamic loading factor for the mounting, with the force applied in any possible direction. A 20-pound propane tank weighs about 17 pounds empty (I think) so a full one would weigh 37 pounds. Your rack would thus need to be capable of supporting a static load of about 300 pounds.

To protect from tire blowout, you probably need a wall of at least the same thickness as the wheel wells, which are 16 ga. steel sheet in my bus. I plan to use that plus possibly an inner lining of plywood of some thickness, to provide some composite armor against bits of tire (since my tanks will be immediately in front of a rear wheel).

When I rebuilt my floor, I built it with a metal box (open to the underside) where my oven is situated, coming up to the level of the chair rail. This will allow me to keep the bottom of my tanks well above the edge of the skirt.

 

[A_Bus_Called_Quest]

The RVIA guidelines for external propane tanks use an 8X dynamic loading factor for the mounting, with the force applied in any possible direction. A 20-pound propane tank weighs about 17 pounds empty (I think) so a full one would weigh 37 pounds. Your rack would thus need to be capable of supporting a static load of about 300 pounds.

To protect from tire blowout, you probably need a wall of at least the same thickness as the wheel wells, which are 16 ga. steel sheet in my bus. I plan to use that plus possibly an inner lining of plywood of some thickness, to provide some composite armor against bits of tire (since my tanks will be immediately in front of a rear wheel).

When I rebuilt my floor, I built it with a metal box (open to the underside) where my oven is situated, coming up to the level of the chair rail. This will allow me to keep the bottom of my tanks well above the edge of the skirt.

Hey thanks for the quick reply Musigenesis!
300lbs is a lot! Good to know though, that really puts it into perspective.
I'm not too familiar with metal working - do you think 1/8" thick angle iron (home depot), welded at the corners will be strong enough? I can add some 45° cross beams at the corners to help support from side-side motion.

Though we technically aren't too far along to cut a hole in the floor for the tank - I would really rather not. This is going to cause the 20lb-ers to hang below the exterior side-wall.
If I add an exterior plate to cover them from the outside - do you think DOT will let it slide? I'm thinking if they cant see the tanks from the outside - that might help me slide by.

I'm really hoping someone restocks the horizontal tanks - I would rather spend the extra $$$ for peace of mind (and less work). Looking at the Flame King 12.5g Horizontal tank, I saw it on Amazon for $330, though it has been delisted since. . .
- originally looked at the Manchester tank 1175TC(?) but it states you have to fill in vertical position, so lame!

I really don't want to spend $700 on a propane tank . . . which brings me ALL the way back to the original 20lb standard BBQ tank.

 

[ewo1]

What about forklift lp tanks?
They can laid horizontally?

Has anybody use them on their build?

 

[musigenesis]

Hey thanks for the quick reply Musigenesis!
300lbs is a lot! Good to know though, that really puts it into perspective.
I'm not too familiar with metal working - do you think 1/8" thick angle iron (home depot), welded at the corners will be strong enough? I can add some 45° cross beams at the corners to help support from side-side motion.

A 1/8" x 1.5" angle steel (or thereabouts) box should be more than adequate to support 300 pounds (much more, really) assuming that the welds are good. I don't think you need angle beams or gussets at the corners, especially not if you weld sheet on the outside to form an enclosed box.

Though we technically aren't too far along to cut a hole in the floor for the tank - I would really rather not. This is going to cause the 20lb-ers to hang below the exterior side-wall.
If I add an exterior plate to cover them from the outside - do you think DOT will let it slide? I'm thinking if they cant see the tanks from the outside - that might help me slide by.

I don't think DOT is going to be concerned with you in any way, and the NFPA standards I referenced are really just guidelines.

 

[A_Bus_Called_Quest]

What about forklift lp tanks?
They can laid horizontally?

Has anybody use them on their build?

Definitely not an expert - but they way I understood it was that forklift tanks are in horizontal position because the engine actually runs on liquid propane - instead of our RV appliances using propane gas.

I learned this AFTER I ordered my original 30lb vertical tank, thinking I could just lay it on its side - Its gas right?! no . . . apparently not right, it is liquid, then released in gas state to our appliances.

 

[Danjo-SKO]

I have 20 inches from the bottom of the floor to bottom of skirt so I built a platform between framing out of 1/8” steel and bolted it on with grade 8 bolts and made a door.

 

[A_Bus_Called_Quest]

I have 20 inches from the bottom of the floor to bottom of skirt so I built a platform between framing out of 1/8” steel and bolted it on with grade 8 bolts and made a door.

The great Danjo - i was just looking at your post, and these pics, the other day! You gave me the courage to attempt the 20gal in the first place haha.
I'm thinking my setup will look very similar to yours, but I will have to build a box, or modify and lower the existing storage box, to accommodate the height of the tank.
I have roughly 16" from the bottom of the undercarriage and only 14" from the bottom of the horizontal (left/right) frame channels.

I might try to cut out the existing storage box, and lower it with some flat 16g steel . . Like a reverse roof raise, only on the storage box [emoji854]

 

[ewo1]

Definitely not an expert - but they way I understood it was that forklift tanks are in horizontal position because the engine actually runs on liquid propane - instead of our RV appliances using propane gas.

I learned this AFTER I ordered my original 30lb vertical tank, thinking I could just lay it on its side - Its gas right?! no . . . apparently not right, it is liquid, then released in gas state to our appliances.

You may not be an expert but your were right!
I googled it and this is what I found, just like you said!

Is forklift gas the same as BBQ gas?
Gas for forklifts and barbecue grills are both made from the same type of propane gas. ... Assuming your forklift is powered by liquid propane, a forklift tank is equipped with a dip tube that allows you to draw liquid fuel from the bottom of the tank.

 

[A_Bus_Called_Quest]

After the bus build we all become certified carpenters, electricians, plumbers, hvac techs, diesel mechanics and propane technicians - am I right? Will there be a graduation ceremony I wonder.....

 

[Doktari]

I like how the 20 lb tanks fit perfectly in a milk crate. I’d like to find some of the old steel milk crates. Nice thing about the horizontal RV propane tanks is they are exempt from the expiration and inspection regulations. I have a couple of them but they don’t fit well under my cutaway van bus body. You can have them cheap.

 

[A_Bus_Called_Quest]

I like how the 20 lb tanks fit perfectly in a milk crate. I’d like to find some of the old steel milk crates. Nice thing about the horizontal RV propane tanks is they are exempt from the expiration and inspection regulations. I have a couple of them but they don’t fit well under my cutaway van bus body. You can have them cheap.

I was thinking the same about steel milk crates - if I could get one of those I would be half way there!
Another thing I like about 20lb tanks is the option to refill, or exchange empty for full tank if refill is not available. This way I could detach the depth tank and carry it up for exchange rather than backing the bus up to fill station.

Are your horizontal tanks vertical fill, or horizontal fill? That was the main issue I was having with most horizontal tanks I've found, they are req to be vert filled and it seems like more of a hassle to detach from underbody mount and carry a large tank up vs the small, portable-ready 20lb tank.

 

[A_Bus_Called_Quest]

Ps.
I think my solution is going to be cutting the existing storage box about 1/3of the way down and dropping it 6 or 7 inches with angle iron corner supports. Then I will make a exterior-facing plate to cover the gap between the bottom of the box and existing storage door, so you cannot see / tamper with the tanks from the outside.

I'll have to get a new handle/lock mechanism for the door, or chip off the paint - someone a the bus yard painted over the lock

 

[Doktari]

My horizontal RV tanks are horizontal fill. They have big flanges to bolt them up under a vehicle. They would probably work in a full size bus but don’t fit under my cutaway van bus.

 

[Danjo-SKO]

Ps.
I think my solution is going to be cutting the existing storage box about 1/3of the way down and dropping it 6 or 7 inches with angle iron corner supports. Then I will make a exterior-facing plate to cover the gap between the bottom of the box and existing storage door, so you cannot see / tamper with the tanks from the outside.

I'll have to get a new handle/lock mechanism for the door, or chip off the paint - someone a the bus yard painted over the lock

Just be sure that a major part of the bus forward of the tank is lower than the bottom of the tank

 

[A_Bus_Called_Quest]

Just be sure that a major part of the bus forward of the tank is lower than the bottom of the tank

Definitely, good looking out! There is a pretty serious i-beam frame that holds the air suspension sysyem, just behind the rear axle but in front of the propane tanks.

 

[Seb1]

I bought a stainless steel grill propane pull out drawer (here : https://www.wayfair.com/outdoor/pdp/cal-flame-slide-out-propane-drop-in-drawer-fmn1037.html?piid=)(was $230 at the time, looks like price went up), cut the bus skirt and bolted the drawer frame all over the place + added additional metal straps in the back to secure to bus floor and structure. I then added 2 locks to avoid the drawer to open while taking sharp turns...
https://drive.google.com/file/d/1mbCmVJRjeI0DxEjjjRrScHpZ5pQzO8ze/view?usp=sharing
https://drive.google.com/file/d/1I2qDbfBIIa7kVHCclMP1Yq5BnckMAKa7/view?usp=sharing
https://drive.google.com/file/d/1Zn9-4Q7pf4_R0nnLpuT7gui7J3zKGTia/view?usp=sharing

 

[A_Bus_Called_Quest]

That is a sweet propane locker! I thought about something like that, then I saw the prices. :hide:

I think I'm going to try to build something similar - I thought to mount the propane rack on a drawer slide to make my life easier getting it out of the storage compartment . . . we'll see how it shakes out.

Next week we're supposed to get a break in temperature here in Vegas so I'll be busting out the angle grinder to cut that storage box in half, drop it 6" and re-attach with some sheet-metal-bandaids.

 

[LargeMarge-TC]

...do you think 1/8"...angle iron (home depot), welded at the corners will be strong enough? I can add some 45° cross beams at the corners to help support from side-side motion...I'm really hoping someone restocks the horizontal tanks - I would rather spend the extra $$$ for peace of mind...I really don't want to spend $700 on a propane tank...

.
a)
I remember a thread about mounting several Group 31 batteries -- about 60# each -- in a box cobbled from hardware-store plumber-strap.
There were arguments against following through on that concept.
.
I suggested a visit to a heavy-truck dismantler.
I encouraged the cobbler to compare her thoughts to a factory engineered battery-box designed to contain a constant multi-axis 'explosion' as the vehicle traveled through earthquakes and rioters.
During a hurricane.
.
b)
For return-on-investment, I am inordinately fond of wrecking-yards (aka 'dismantlers').
For the reliability of factory engineering, I delight in a 'score!' from a wrecking-yard.
.
Eugene, Oregon.
Our various wrecking-yards receive a dozen-plus RecreationVehicles weekly
Saleable components are quickly removed, the husk is crushed.
.
If I was me, I might look around a wreckers at a pile of RecreationVehicles.
I bet a nickel the shape/capacity you need is moments from heading to the smelter.

 

[A_Bus_Called_Quest]

Got the tank mounted! With room for a partner if needed. I still have to attach an 8" sheet of metal to the door to cover the dropped storage box, and will probably hit the corners with some angle iron just to be safe... but I'm very happy with how the whole thing came together.

First I cut the storage box about 4 ines up from the bottom. This gave me plenty of meat on each side of the cut to bolt on my sheet metal extension.
For the extension sheet I cut up the old ceiling sheet metal from the front of the bus. It is perforated so I thought it would be good to allow the box to breath incase of a leak.
Using a hitch propane mount (all i could find for a reasonable price) and eventually a ratchet strap to hold the tank steady, I can fit 2 tanks perfectly inside the box.
Adding 2 locks later in the week. One to the door itself and one to the propane mount threads.

I stood on the box and jumped around with give or creaking from the box so I think I'm good up to at least 200 - 250lbs of downward force.

Any critique is welcome, I want to make this pretty bomb-proof.
The rear axle sits way lower than this storage box so I think I am OK with clearance - I only dropped the box 7".

Thanks again to the whole crew for the information and support in this one!