I have had my van in storage for 8 months and as advised had drained the two 90ltr undervan tanks .
Today I flushed them and then shut the tank values off and filled them as I had done many times with the hose .
Much to my surprise there was a very loud bang one of the water tanks looks like it has slit and just dumped the water.
Normally when the tanks are full it spits out of the water cap.
To make it more confusing it did work as it should the first time I flushed teh tank earlier today.
I am going to have to drop the tank out to confirm it has split next week end .
If it even possible to bust a water tank under pressure.
What a day and the bolts to get the tank out look a little nasty to get to.
Ideas
-- Edited by Col Rennie on Sunday 3rd of December 2017 07:59:29 PM
-- Edited by Col Rennie on Sunday 3rd of December 2017 08:09:54 PM
-- Edited by Col Rennie on Sunday 3rd of December 2017 08:13:36 PM
Peter_n_Margaret said
08:29 PM Dec 3, 2017
Sounds very much like the vent is blocked or non existent.
Cheers,
Peter
dieseltojo said
09:56 PM Dec 3, 2017
Hi Col Rennie,
Yep, I never advise a tank to be emptied for storage. I never have in 50 years of camping and never had a water problem.
That said, it is hard to say what caused it to split. I would say that due to being empty it has been able to expand and contract more than the poly would like, then the incoming pressure was too much for it. Or a manufacturing fault.
As already noted, a hornet might have built a nest in the expansion area, but more likely the over flow hose might be kinked or trapped with the movement of the empty tank.
I remember this happening to a bloke years ago and the van was moved by the caravan (long term parking) mob and then placed onto a site. They must not have taken it over even ground, or the van sunk a bit into the mud. Or the tyres were low.
Anyway the tank corner was hit on something and damaged.
I asked the owner where it was parked and even showed him what they had dragged the van across.
Hard to say with out a good look mate.
Col Rennie said
10:20 PM Dec 3, 2017
Thank you for the feed back.
It is greatly appreciated.
I will disconnect the overflow pipe and run water through it to ensure it is clear and drop the tank out this week end to see the actual damage .
Thank you again
Tony Bev said
11:28 PM Dec 3, 2017
As others above have said, it is hard to say without removing the tank, and looking at it
From my observations, a lot of rubber and plastics, suffer from age hardening, due to the cold and heat cycles
Perhaps over the eight months of storage, the empty tank has been contracting in the cold, and expanding in the heat, which may have caused a weak spot
Or the tank may have had a weak spot from new
I removed the 59 litre tank from my old caravan to clean it out, the thickness was not uniform
As far as the rusty bolts go, use a wire brush and plenty of CRC/Penetrine before trying to undo them
Also (if the bolt head is not welded in), use two ring spanners and try to loosen the nut off, by going back and forth
mustangdude said
07:25 AM Dec 4, 2017
I'd be surprised if the tank was made of ABS and it split. That stuff is tuff.
Hopefully it's a fitting came unscrewed or snapped off. You're going to undo the fittings before dropping the tank so hopefully you find an easy fix.
Peter_n_Margaret said
09:14 AM Dec 4, 2017
99.9% of commercial water tanks and most custom made ones are polyethylene, either blow moulded or rotation moulded (with custom ones hot air welded). A few custom made ones might be hot air welded from polypropylene or ABS. If it is split and made from polyethylene it can probably be repaired by hot air welding provided the wall section is sufficient (there are some very thin junk ones about).
I may be easier to cut the bolts off and replace them with new ones.
Cheers, Peter
-- Edited by Peter_n_Margaret on Monday 4th of December 2017 09:16:40 AM
lizard said
09:44 AM Dec 4, 2017
We had one of our water tanks split after filling - tank split on the seam ..... my vent was clear - water spurted out .... !!! Replaced the tank
Possum3 said
02:34 PM Dec 4, 2017
I had one split on and Old Viscount 1977. Tanks are cheap -replace and ensure overflow vent isn't blocked
Peter_n_Margaret said
07:36 PM Dec 4, 2017
And buy the heaviest one you can find.
Cheers,
Peter
PeterD said
11:21 PM Dec 4, 2017
I have not heard of one splitting for quite some years. Back in the 90s it used to be common where people filled their tanks with full flow from a tank and the hose was pushed a fair way down the filler. . A lot of tanks are formed from two mouldings that are stuck together, they were splitting on that seam.
See if you can get the split welded. Then make sure you have good free flowing breathers. Also take a little more time to fill your tanks.
Peter_n_Margaret said
09:30 AM Dec 5, 2017
If you are in Adelaide I may be able to repair it.
Cheers,
Peter
dieseltojo said
01:12 PM Dec 5, 2017
mustangdude wrote:
I'd be surprised if the tank was made of ABS and it split. That stuff is tuff. Hopefully it's a fitting came unscrewed or snapped off. You're going to undo the fittings before dropping the tank so hopefully you find an easy fix.
I would be surprised too mustangdude,
Abs is not considered safe as a food receptacle according to this very cursory search. It also is a lot more expensive than poly carbonate which does not leach into food even when heated.
There is some debate about it, but ABS is generally considered unsafe to use with anything that will touch food. This is because ABS contains toxic chemicals which could leach into your food and eventually, your mouth.
Peter_n_Margaret said
04:51 PM Dec 5, 2017
dieseltojo wrote:
Abs is not considered safe as a food receptacle according to this very cursory search. It also is a lot more expensive than poly carbonate which does not leach into food even when heated.
Errrr...... I have never seen a polycarbonate RV tank. It costs much more than ABS (and is much tougher), but it is used for those transparent 20L upsidedown water bottles.
Nor would have a problem using ABS for a water tank, but polyethylene is cheaper and tougher and there are more appropriate manufacturing methods typically used for polyethylene.
Cheers,
Peter
Col Rennie said
06:40 PM Dec 6, 2017
Thank you all as always this site really helps newbies like me.
Tomorrow I have the time to drop the tank and see for the first time the real damageto the tank
Spoke to the manufacture sounds like the tank has split on the seam as the tanks are two halfs welded together.
Interesting
wish me luck
Peter_n_Margaret said
06:59 PM Dec 6, 2017
Nor have I ever seen a commercially available RV water tank that is made in "2 halves welded together". Most will have what looks like a join, but it is not, it is just a line on the outside where the 2 halves of the mould come together. The tank itself will not have a join (have a look on the inside, if you can). Commercial RV tanks are made by rotomoulding or by blow moulding (Google those terms if you want to learn more). Both methods are commonly used for RV water tanks. Car fuel tanks are blow moulded which is a cheaper process, but the tooling costs MUCH more. Rainwater tanks are only rotomoulded (because of their size). Both processes use polyethylene. Rotomoulded RV tanks will typically be heavier (with thicker walls) and more expensive to make (but cost sometimes has no relationship with selling price).
Cheers, Peter
-- Edited by Peter_n_Margaret on Wednesday 6th of December 2017 07:00:52 PM
Hi I am a newbie but today was just a shocker.
I have had my van in storage for 8 months and as advised had drained the two 90ltr undervan tanks .
Today I flushed them and then shut the tank values off and filled them as I had done many times with the hose .
Much to my surprise there was a very loud bang one of the water tanks looks like it has slit and just dumped the water.
Normally when the tanks are full it spits out of the water cap.
To make it more confusing it did work as it should the first time I flushed teh tank earlier today.
I am going to have to drop the tank out to confirm it has split next week end .
If it even possible to bust a water tank under pressure.
What a day and the bolts to get the tank out look a little nasty to get to.
Ideas
-- Edited by Col Rennie on Sunday 3rd of December 2017 07:59:29 PM
-- Edited by Col Rennie on Sunday 3rd of December 2017 08:09:54 PM
-- Edited by Col Rennie on Sunday 3rd of December 2017 08:13:36 PM
Cheers,
Peter
Yep, I never advise a tank to be emptied for storage. I never have in 50 years of camping and never had a water problem.
That said, it is hard to say what caused it to split. I would say that due to being empty it has been able to expand and contract more than the poly would like, then the incoming pressure was too much for it. Or a manufacturing fault.
As already noted, a hornet might have built a nest in the expansion area, but more likely the over flow hose might be kinked or trapped with the movement of the empty tank.
I remember this happening to a bloke years ago and the van was moved by the caravan (long term parking) mob and then placed onto a site. They must not have taken it over even ground, or the van sunk a bit into the mud. Or the tyres were low.
Anyway the tank corner was hit on something and damaged.
I asked the owner where it was parked and even showed him what they had dragged the van across.
Hard to say with out a good look mate.
Thank you for the feed back.
It is greatly appreciated.
I will disconnect the overflow pipe and run water through it to ensure it is clear and drop the tank out this week end to see the actual damage .
Thank you again
From my observations, a lot of rubber and plastics, suffer from age hardening, due to the cold and heat cycles
Perhaps over the eight months of storage, the empty tank has been contracting in the cold, and expanding in the heat, which may have caused a weak spot
Or the tank may have had a weak spot from new
I removed the 59 litre tank from my old caravan to clean it out, the thickness was not uniform
As far as the rusty bolts go, use a wire brush and plenty of CRC/Penetrine before trying to undo them
Also (if the bolt head is not welded in), use two ring spanners and try to loosen the nut off, by going back and forth
Hopefully it's a fitting came unscrewed or snapped off. You're going to undo the fittings before dropping the tank so hopefully you find an easy fix.
99.9% of commercial water tanks and most custom made ones are polyethylene, either blow moulded or rotation moulded (with custom ones hot air welded).
A few custom made ones might be hot air welded from polypropylene or ABS.
If it is split and made from polyethylene it can probably be repaired by hot air welding provided the wall section is sufficient (there are some very thin junk ones about).
I may be easier to cut the bolts off and replace them with new ones.
Cheers,
Peter
-- Edited by Peter_n_Margaret on Monday 4th of December 2017 09:16:40 AM
Cheers,
Peter
See if you can get the split welded. Then make sure you have good free flowing breathers. Also take a little more time to fill your tanks.
Cheers,
Peter
I would be surprised too mustangdude,
Abs is not considered safe as a food receptacle according to this very cursory search. It also is a lot more expensive than poly carbonate which does not leach into food even when heated.
https://www.google.com.au/search?q=is+ABS++poisonous+&ie=utf-8&oe=utf-8&client=firefox-b&gfe_rd=cr&dcr=0&ei=if4lWuGjKaTM8gfMgbLgBw
Is ABS safe?
There is some debate about it, but ABS is generally considered unsafe to use with anything that will touch food. This is because ABS contains toxic chemicals which could leach into your food and eventually, your mouth.
Errrr...... I have never seen a polycarbonate RV tank. It costs much more than ABS (and is much tougher), but it is used for those transparent 20L upsidedown water bottles.
Nor would have a problem using ABS for a water tank, but polyethylene is cheaper and tougher and there are more appropriate manufacturing methods typically used for polyethylene.
Cheers,
Peter
Thank you all as always this site really helps newbies like me.
Tomorrow I have the time to drop the tank and see for the first time the real damageto the tank
Spoke to the manufacture sounds like the tank has split on the seam as the tanks are two halfs welded together.
Interesting
wish me luck
Nor have I ever seen a commercially available RV water tank that is made in "2 halves welded together".
Most will have what looks like a join, but it is not, it is just a line on the outside where the 2 halves of the mould come together. The tank itself will not have a join (have a look on the inside, if you can).
Commercial RV tanks are made by rotomoulding or by blow moulding (Google those terms if you want to learn more). Both methods are commonly used for RV water tanks. Car fuel tanks are blow moulded which is a cheaper process, but the tooling costs MUCH more. Rainwater tanks are only rotomoulded (because of their size). Both processes use polyethylene.
Rotomoulded RV tanks will typically be heavier (with thicker walls) and more expensive to make (but cost sometimes has no relationship with selling price).
Cheers,
Peter
-- Edited by Peter_n_Margaret on Wednesday 6th of December 2017 07:00:52 PM