How to mount tanks underneath?

[Diesel Dan]

I'm curious how people have mounted water and fuel tanks underneath their buses. My bus' stock fuel tank is mounted directly to the main center chassis frame by a huge 3" tubular steel bracket that is essentially suspended other than that one side that is attached to the frame. No doubt it is soundly engineered due to the size of the metal, but I cannot use that same strategy to mount my auxillary tanks.

I will likely use 55 gallon drums, or something similar for all my water and fuel tanks. The chassis frame obviously offers a solid mounting point for one side, but I don't see any real substantial metal to mount the out-side to. Obviously people are tying into something, and it works, so maybe I'm trying to over-engineer this.

The best approach I can think of is to bolt angle iron across several floor beams tying in to as many points as possible over the full length of the barrel, and then having either some sort of metal straps, or a suspension system of vertical angle iron or threaded studs coming down from the attached angle iron.

Are those floor beams strong enough to support 400+ lbs of water or fuel in a steel 55 gallon drum?

[Eric von Kleist]

Dang, I had about 7 pages of response and then hit the alt-b button.

My suggestion for fuel tanks is: get a used tank off of a truck that has the same frame as your bus. That is what I did. The International frames that you and I have are pretty standard medium truck frames. The brackets and tank that I added to my bus were from an old fleet service vehicle that was sitting in a field. The parts *fit* the frame. Huge advantage. Plus you don't have to figure out how to plumb anything, how to install a sending unit for a fuel gauge, or anything. Fuel line parts are standard. Just drill the holes, and mount the tank....almost.

Normally, you install the brackets on the frame, then put the tank on the brackets, then tighten down the steel straps that hold it on. It's really hard to do it in that order under a bus body! I ended up assemling the whole thing and lifting it up and bolting it in place. The placement of your bolt-holes is critical. These brackets had four 1/2" holes each, which meant drilling eight 1/2" holes in a hardened steel frame. DRILL HARD, SLOW, AND USE OIL. Drill in steps, too -- 1/4", 3/8", 1/2". A day's work if you include taking it off the donor vehicle and putting it on the bus all together.

Here's a photo documentary of the process. http://www.skoolie.net/gallery2/v/Skooli ... n/album52/

The tank was installed for my indefinitely delayed WVO conversion. I chickened out on cutting fuel lines that work *right now*. Now that I moved, I don't have a supply of WVO... But anyway...


As far as holding tanks go....here's my solution: http://www.skoolie.net/gallery2/v/Skooli ... struction/

I just tied mine on with rope! Why not? If the application is correct, it's a useful construction material. People have crossed oceans on boats tied together with rope (not that a bus is a boat, or driving 45 mph is the same as sailing the pacific, but the material is a legtimate construction material.)

http://www.skoolie.net/gallery2/v/Skooli ... t.jpg.html

My tank is made from a 14(?) foot long piece of 8" sewer pipe. PVC fittings for the pipe. I used a Spanish Windlass in the construction process, which was fun! The plumbing is all standard household stuff.

The flat discharge hose for my tank fits an agrigcultural quick-release fitting for irrigation hoses. There is a whole bunch of neat bus applications for the agricultural irrigation products. I got my hose parts at Tractor Supply. I don't dump sewage, just graywater, so the flat discharge hose is fine, and it rolls up and fits in my battery box. It also has a standard sewage system 4" PVC fitting on the discharge end, so I can screw it onto a hook up at a campground or RV Park.

[Eric von Kleist]

I've been living in and working on my bus for almost 5 years now, while I have been in school.

I'm pretty satisfied with the install. The tank made from sewer pipe only has a 20 gallon capacity, but it is only for graywater (I have a composting toilet), so it doesn't have to be big. (Plus, you can just dump the graywater on the ground -- the law varies by location.)

It is generally considered a big no-no to weld on the flanges of truck frames. Most often, they are heat treated, and welding them would weaken them by affecting the heat treatment in that one spot. (Look at newer semi-truck and trailer frames-- they usually have big stickers that say, "Do not weld flanges." Drilling and bolting the web, however, seems to be acceptable from an engineering standpoint.

[jam0o0]

do not weld to truck frames. but welding to things on your bus will not mess with the computer if all your grounds are there and functional and you attach the welding ground properly.