Forum Discussion

avarusbrightfyr's avatar
Feb 22, 2021

50 Gal Water Tank Mounting

Hello!

I was wondering if anyone had come up with a highly secure way to mount a large, heavy water tank under a travel trailer. I have a Winnebago Minnie Plus and it came with a 50 gallon water tank mounted under the floor inside the frame, but in their infinite wisdom Winnebago seemed to think that two lengths of thin L channel attached to the frame with flimsy self-tapping screws and a sheet of particle board underneath was enough to support 400+ pounds of water. I've tried jury rigging it back in a couple of different ways, including round bar and now cable straps, but nothing has really worked to my satisfaction. It's already fallen out twice now and it's been parked since I bought it (I live in it in a full time park). I have no idea how they expected that to hold up with any amount of water in it jostling down the road, and I do eventually want to get myself into a position to start travelling full time, so I need to figure this out.

Anyway, I'm thinking some kind of square bar grid or something that rests directly on the frame to support the entire bottom of the tank. Has anyone done anything like this and found that it works? I don't have the skillset to do it myself, and I don't want to end up paying someone to fabricate something for me only to find out it's going to break anyway. And while it seems simple enough to have someone weld a grid of some kind together, part of the trick would be making it removable so I can get the tank out if I need to.

Alternatives are always welcome, of course!

Thanks!
  • opnspaces wrote:
    What failed allowing it to fall out? Did the straps bend or the self tapping screws fail? If the screws failed did the pull out of the frame or just pull apart?

    If the straps bent or sagged you can get some thicker angle or tube steel to stretch across the frame under the tank.

    If the self tapping bolts broke or came out you can look into bigger self tapping bolts or even through bolt with a bolt and a nut.

    If the bottom of the tank is flush with the bottom of the frame then consider adding a third or even fourth cross piece under the tank.


    The first thing to fail were the self-tapping screws, which allowed the supporting l-beams to twist and the tank fell out full of water. The only thing that stopped it from crashing to the ground was the underbody cover. I was in the trailer when it happened and I thought someone had crashed into me.

    I've come to the conclusion that I can't really use the original hardware at all because over time trying to jury rig a solution, the original support beams have warped and just don't seem reliable anymore. I currently have it rigged up with cargo straps, which seems to sort of work, but I don't think it's a long term solution, especially since I think movement will eventually cut through them.

    That's why I'm looking for a preferably easy design for something I can just rest on the frame of the trailer and maybe keep in place with a bolt or something that supports the entire tank from the bottom.
  • My 36 gallon fw tank is supported on 3 sides by welded in place angle and on the fourth side by the driver side frame I Beam. My 40 gallon each black and grey tanks are supported on 2 sides by 2 inch angle. They are bolted to flat bar tabs that are welded to the webs of the main frame I-beams.
  • I used 1 1/2"x 1 1/2"x 3/16" angle iron when I reinstalled my 105-gallon tank several years ago and have had no issues since.
  • OP if you can provide pictures of the tank and existing supports it would be easier for us to describe what you need.
  • My 2004 Fleetwood Pioneer has a 50 gallon fresh tank that is supported by two square bars (C channel might be a better description) fastened to the frame via nut and bolt. I drag that trailer through serious back country with lots of major bouncing going on with zero issues.
  • on my outback there was enough room between the water tank and floor that I was able to use 3/4" plywood under the tank and then screwed the plywood through the channel to keep it ancorred. then I put three pieces of angle iron crosswise as well to support it,

    We always travel with full tanks and no problems.
  • Mine uses 3 pieces of 1 inch square tube screwed to the crossmembers per tank. It has 2 tanks that are 60+ gallons each. I often travel with them full and no problems yet.
  • What failed allowing it to fall out? Did the straps bend or the self tapping screws fail? If the screws failed did the pull out of the frame or just pull apart?

    If the straps bent or sagged you can get some thicker angle or tube steel to stretch across the frame under the tank.

    If the self tapping bolts broke or came out you can look into bigger self tapping bolts or even through bolt with a bolt and a nut.

    If the bottom of the tank is flush with the bottom of the frame then consider adding a third or even fourth cross piece under the tank.
  • Contact a heavy duty truck/trailer shop, they would know how to do the job.

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