Holy sagging water tanks, Batman!

[mosseater]

Since I was already having a venting problem with my FW tank, I decided this weekend to look and see why there seemed to be a bulge in my enclosed underbelly.

The venting problem was a pretty simple one. The vent tube was sagging about an inch below where it entered the tank, so there was about 10" of water it that had to be either sucked in or blown out before it could vent properly. A couple wireties solved that in short order.

The bulge was a different issue. SunnyBrook did a nice job installing and supporting the 50 gal. tank between two "Z" struts which were firmly anchored to the frame rails with the tank held captive between them on a 1 1/2" ledge. The problem comes with their rational to support under the tank with a piece of 1/2" OSB sitting on the ledge of the "Z" strut. That, in and of itself, isn't a problem, although it's marginally able to carry the load of 400 lbs of water without bowing. The root of the problem is with their complete lack of allowance for the condesation which forms between the tank and OSB, and slowly rots the OSB, taking with it all support. The wetter it gets, the more water it collects, and the more it rots. The whole center about 1' around was so spongey I could put my hand right through it.

The repair could have taken several paths, but I chose to change out the piece of OSB with 5/8" plywood, which I cut to fit as closely as I could. I bored a 3/4" weep hole in the middle and stapled two strips of plastic, one on either side of the weep hole, to aid in air circulation and drainage of condensation. After got the whole high- tech mess up and in place, I ran two banding straps under the plywood from one "Z" strut flange to the other to help support the tank and also keep the struts for torquing under load. I filled the tank before re-installing the underbelly to watch how it perfomed, and it barely bowed at all. I think it's going to last a long time.

It was also nice to be able to shore up some wiring with cable ties and get a good look at the innards of the beast. At least I know that problem won't rear it's ugly head at some inopportuned moment this season. If any of you folks have some question about the security of your tanks, I highly recommend you take a look. That's a lot of weight hanging under there!

[westend]

myredracer wrote:

2012Coleman wrote:
I agree that they don't appear to be the greatest welds, but nitpicking them is being trivial. Looks to me like angle iron tacked on to stop movement of the tank.

Nobody is nitpicking, it's just that that one particular weld is interesting in a funny way and looks like a tumor. I've never seen a weld like that and doubt I could make one like that no matter how hard I tried.

It doesn't take any trying. Just leave the slag on the weld, it will look like that.

[myredracer]

2012Coleman wrote:
I agree that they don't appear to be the greatest welds, but nitpicking them is being trivial. Looks to me like angle iron tacked on to stop movement of the tank.

Nobody is nitpicking, it's just that that one particular weld is interesting in a funny way and looks like a tumor. I've never seen a weld like that and doubt I could make one like that no matter how hard I tried.

[SoundGuy]

2012Coleman wrote:
Looks to me like angle iron tacked on to stop movement of the tank.

Those are tabs welded to the two support braces to prevent the tank from shifting side to side ... tank doesn't move in the slightest. And yes, each brace is secured to brackets welded to the trailer frame - 2 bolts per bracket, in all a total of 8 bolts ... makes removing the braces for painting a simple task. 🙂

Anyway, my post last year to this thread was simply to add to the discussion about lousy tank support by trailer manufacturers and offer my own solution, not to get into some mindless debate with someone who passes judgement from an online picture over the welder's qualifications. :S Fact is, that solution was implemented nearly 3 yrs ago and it's working just fine, "lousy" welds included. :B

Final point - I recently looked under a brand new 2017 Coachmen Freedom Express 192RBS and noted that Coachmen hasn't made any improvement at all to fresh water tank support ... it's just the same now (terribly inadequate) as it was on my 2014 model. Pity those who have an enclosed underbelly, can't see whether their tank(s) are properly supported or not, and find out the hard way that it's the latter. :M

[2012Coleman]

myredracer wrote:

SoundGuy wrote:

Old-Biscuit wrote:
I like the idea/concept of the supports....BUT
Your dealer needs to send his 'welder' back to school. Look like Lippert Pin Box attempts at welding.

It's coming up on 3 yrs now that we've owned this trailer and these supports are just fine despite your "expert" commentary to the contrary. :R

I think what Old-Biscuit is referring to is a pretty funky-looking weld. Maybe there is some further welding that can't be seen in the photo that's adding some strength?

Those welds have nothing to do with the supports which are bolted on as plainly seen in the original picture. I agree that they don't appear to be the greatest welds, but nitpicking them is being trivial. Looks to me like angle iron tacked on to stop movement of the tank.

[myredracer]

SoundGuy wrote:

Old-Biscuit wrote:
I like the idea/concept of the supports....BUT
Your dealer needs to send his 'welder' back to school. Look like Lippert Pin Box attempts at welding.

It's coming up on 3 yrs now that we've owned this trailer and these supports are just fine despite your "expert" commentary to the contrary. :R

I think what Old-Biscuit is referring to is a pretty funky-looking weld. Maybe there is some further welding that can't be seen in the photo that's adding some strength?

[SoundGuy]

SoundGuy wrote:
I drew this to attention of my dealer and he had his welder install metal support braces under the tank.

Old-Biscuit wrote:
I like the idea/concept of the supports....BUT

Your dealer needs to send his 'welder' back to school. Look like Lippert Pin Box attempts at welding.

Interesting this old topic should resurface as it reminded me of your previous ill informed comment about my fresh water tank supports. :R It's now another year later, the tank supports are working just fine thank you and in fact this spring as I was prepping the trailer for the season I removed the brackets to paint them and add a 2' x 4' piece of plywood between the tank and support brackets to better spread the weight of 30 gals of water in the tank. It's coming up on 3 yrs now that we've owned this trailer and these supports are just fine despite your "expert" commentary to the contrary. :R

Fresh Water Tank Support

[myredracer]

We don't dry camp and fortunately don't have to worry about tank supports. I wouldn't want to travel very far though unless I had checked the supports. One of these days I'm planning to pull down the entire underbelly to see what there is to see including tank supports and am 100 percent positive I'll find lots of substandard stuff that need addressing.

Many TTs have a low cargo carrying capacity and ours is one of them. Our trailer all loaded up for camping for two is just under the GVWR. Just one full holding tank would put us over the GVWR. All 4 tanks if full would result in the weight of the trailer being something like 900+ lbs over the GVWR - not good. If they allegedly design TTs so you can tow with full tanks, how is it possible to end up being so far over the GVWR? I wonder how many have the same issue?

Do tank manufacturers have anything to say about supports for their tanks? What does someone like Nash do for their tanks, considering that their frame are off-road certified?

[AtlPhilip]

One comment about weight. The FWT on my 12yr old Starcraft sags as depicted and has never had any water in it.

I contacted Starcraft and their only suggestion was to replace the tank. I asked about installing a bulkhead and they only offered this, "you should be safe in adding a low point drain or a sort of plug as long as they are sealed correctly"

I'm considering putting a 1/4" SS self-tapping screw at the low point, and simply removing it to completely drain the tank. My concern is that it may start a crack or tear.

[camperforlife]

JJBIRISH wrote:
They have been doing it the same way for years and having trouble with it for as long…

My FWT fell out from under my Sunnybrook trailer and skidded across the highway and smashed into a guard post… the piece of OSB when airborne like a Frisbee and very fortunately didn’t hit anything…

Mine was repaired by making and bolting 3 pieces of heavy flat stock across the bottom of the tank… no way possible for it to fall after that or bow on the bottom…

JJbirish, good to see you back.

[westend]

Thanks again!

[69_Avion]

westend wrote:
Thanks for the reply. I'm thinking of building an aluminum framed single axle utility trailer and am thinking about what type of suspension would be best. The trailer wouldn't be designed for real heavy hauling and no long trips are planned. I like the ease of installation of the Torflex axles.

I hate to get too far off the OP's subject, but lightweight trailers are some of the hardest to get good axles for. I built a few trailers for welders and generators and getting a good axle is difficult. The lowest, decent, axle is in the 3,000-3,500# range. Usually, below that the spindle, hub, and axle are junk. My welder/generator trailers were going to be in the 2,000#+ weight range. If I used a leaf spring single axle rated at 3,500# the trailer would bounce down the road. The rubber torsion axles ride better and are more forgiving once you get them loaded to about 60% of their weight rating or higher. What I did is buy 3,500# Flexiride axles and had Arizona Axle install the rubber with the center part missing. That gave it the stability in the tube that it needed, but the "give" required for a 2,500# rating. I had the best of both worlds, a quality axle, and it rides really well. These trailers are an example of where the Flexiride brand payed off because I had to adjust the ride height on the trailers.

[westend]

Thanks for the reply. I'm thinking of building an aluminum framed single axle utility trailer and am thinking about what type of suspension would be best. The trailer wouldn't be designed for real heavy hauling and no long trips are planned. I like the ease of installation of the Torflex axles.

[69_Avion]

westend wrote:
Very nice job on the tanks, Avion. That is how all fresh water tanks should be supported, Once they start sagging and bulging, there develop pockets where water can sit and that is bad news for growth of organisms.

I see you chose Torklex style axles for this build. Do you use then exclusively for these camping trailers?

That particular axle is a Flexiride because I can adjust the torsion arm angle on both sides in about 30 minutes. The Torflex can't be adjusted.
As far as type of axle, I use Flexiride rubber torsion axles on a single axle because they ride better. The above single axle is a 7,000# Flexiride. I usually don't like to go that heavy for a single axle, but in that particular application I didn't have a choice.
When building a tandem or triple axle trailer I always use leaf springs because of the equalizer. They take more time to build because of all the shackle mounts, but they have a better suspension. Multiple rubber torsion axle trailers can put all the weight on one axle instead of both axles when you hit a large bump. That is really hard on the axle.

[westend]

Very nice job on the tanks, Avion. That is how all fresh water tanks should be supported, Once they start sagging and bulging, there develop pockets where water can sit and that is bad news for growth of organisms.

I see you chose Torklex style axles for this build. Do you use then exclusively for these camping trailers?