Fresh water tank sagging

[Lilbird5466]

Hello all,

I’m new to this forum and was hoping to her your expert opinions/suggestions on how best to solve this issue with our Autumn Ridge 24 BHU. We believe the pressure inside the fresh water tank was too high and caused the sagging of the fresh water tank, as well as the support structures. We believe we have solved the issue of how it happened and fixed it, however we are now wondering how best to solve the damage that was done to the tank and support beams.

Attached pictures of the damage.

[Flyer15015]

First, freshwater tanks are not usually pressurized. It should have an overflow tube.
Second, the "support beams" look like pretty chinsey angle iron.
You should get some real and heavier CHANNEL iron or I beams in there for support.
Third, use more than you have now
And don't forget to put some padding atop the support rails.
I use wash machine dump tubing split with a razor blade.

JMHO
Mike in Colorado

[TandW]

Welcome aboard!
Upgrade to 2x3 T-channel with bridging across the middle of the span. Good luck!

[Old-Biscuit]

Weight of water and cheap supports are reason tank is sagging

Additional supports will take care of the sagging

DIY or have a trailer shop fab/install more cross supports before your tank falls out

[rrsutherland]

Agree with both previous posts and I would suggest not reusing that tank.

[creativepart]

Travel with less than full tanks until you get that reinforced. It's not unheard of for those things to fall out on the road while driving. A full tank of fresh water weighs just under 500 lbs on that TT.

All the other suggestions are spot on.

[Lilbird5466]

Do you mean re-inforce the beams or get an entirely new fresh water tank?

[TB673]

Originally Posted by Lilbird5466

Do you mean re-inforce the beams or get an entirely new fresh water tank?

Don't reinforce the Angle Iron that is there, replace with Channel Iron, and replace the tank as it has been structurally compromised. JMHO



Tim

[Persistent]

Ok, here is a dissenting voice.

The bulging plastic looks normal. 500 pounds of water inside a plastic tank is likely to do that. The plastic wall of the tank is not going to look flat after carrying all that water. Tensile strength of the plastic wall keeps the water in.

Cross supports are thin. That is how the designer kept the weight of the trailer down. The same principle has probably been used throughout the TT.

Five years ago there were reports of inadequate tank supports. Tanks came loose and had to be beefed up to work well. That discussion has faded, but the fear is still there.

The design does not look the same as the old Voltage toyhauler tank supports. However, if you want to improve it, then add additional supports and leave the existing supports alone.

The plastic tank wall will still bulge between the supports, but not nearly as much. The existing thin angle supports will be carrying a lot less load and thus are less likely to fail.

Possibility of failure is more likely related to the quality of the cross beam welds or bolts. Check for signs of movement around joints or fatigue cracks next to the welds.

You do not need a new plastic tank.

Trust me I am an internet expert!

[Dave Pelletier]

Remove the weak 1.5" x 1/8" angle and replace with something much stronger. I'd probably use HSS that was 3/16" thick. 2x2 or 2x3

[Tomahawk]

Hmm...
I am not exactly sure what I am looking at. The tank on the left seems like it is installed correctly, like the type of material and construction I'd expect, and looks fine. The thing on the right supported by the bent up angles seems wrong on many levels. It is not supported the way I'd expect. Normally tanks are edge supported. Cross strapping can help but would not normally be the primary support. Tanks are reinforced at the support points to prevent local failures where load is introduced. The material of the tank looks odd, like it has been greatly over stressed or gotten close to the melting point while loaded. That should not happen in normal use. I am not sure how that could happen. I can think of two ways to over stress a tank, both involve not having a vent. If there was no vent and the check valve in the pump leaked the tank cold reach the pressure of the city water supply. If the fill valve was threaded (not normal) and there was no vent you could reach the city water supply pressure. both of those scenarios could over stress the tank. I the 4 angles carry all the load from a 500 LB tank they might be close to their strength limit if they are a low strength aluminum.
The OP said they think they know how this happened, I'd like to hear that to help understand what might need replacing.

[CharlesinGA]

You can easily "inflate" a water tank and damage the supports by simply shoving the hose in the fill port. It blocks the port to the point that the air cannot escape and the rather small air vent is designed to allow air INTO the tank as you pump water out into the sinks, shower, etc. The vent is not designed to nor will it exhaust enough air to keep the tank from expanding. Use an adapter, either home made from box store parts, or one bought from Camco or the like.





This will air to escape around the small fill tube while the water is running in.

Charles

[Tomahawk]

Originally Posted by CharlesinGA

You can easily "inflate" a water tank ...
This will air to escape around the small fill tube while the water is running in.
Charles

Good to know. A water hose does not fit in my fill tube anywhere close to tight enough to seal. When I overfill, water just comes gushing out and pushes the hose out. I like the adapter you show because the flex tubing seems much better than what I do now and especially, the shut off built in. That makes it a one man job instead of me holding the hose in place and my wife at the ready at the hose bib to shut off.

[glwinger]

This is what I used. Superstrut, 13/16 high x 1 5/8 wide. They also have clamps to secure it to the trailer frame. I placed one between each of the ones that were welded at the factory.