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Topic: Water tank sweating (Read 608 times) previous topic - next topic

Water tank sweating

  We live in East Texas and travel the South mostly. Our water tank has a problem with sweating during change of seasons. When we are out at our place in South New Mexico with the low humidity we don't have a problem. As you know this can happen during any period of time if the temp and humidity is right. When we have our water tank out for cleaning and service we always check and make sure the seal between the floor and wall is in good shape so any moisture won't seep through into the rear bulkhead.

Any thought, suggestions, personal knowledge that you could share would be helpful in reducing the sweating problem.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Water tank sweating

Reply #1 –
Perhaps a small fan.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Water tank sweating

Reply #2 –
Quote from: Pamela & Mike –
When we have our water tank out for cleaning and service...
@Pamela & Mike

You take your water tank out of the coach for cleaning?  Gotta say this is the first time I've heard of doing that.  How often?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Water tank sweating

Reply #3 –
Chuck,
There is more to the story than appears.  Yes the tank does come out to check the floor seams on occasions and while it is out we sanitize it with KMnO4 but this time it is for a repair also.  The top of the tank has become concaved due to the Aqua Hot hoses that feed the radiators in the basement laying on top of the tank. With us using the basement heat a lot this has caused a 2" sag in the top of the tank across the !8" width. No this didn't just happen as I have been watching it for a while and just now decided to do something to it as we are at home base for a while. As this repair progresses I will be taking pictures and will do a write up after the project is complete. It isn't a big job to remove our tank as we had it out and on some milk crates in about an hour. It would be advisable to check the floor to bulkhead seam as a bad calk joint hear will let water in to the basement floor sandwich.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Water tank sweating

Reply #4 –
What about using insulation, at least on the top where the heat is taking it's toll, or wrap the AH hoses in header wrap or the equivalent?

Re: Water tank sweating

Reply #5 –
I'm glad to hear that removing the tank is not much of a problem.  I don't plan to do that although maybe I should to check the caulking along the seam.  I doubt if there is any way to prevent sweating unless you keep the tank warm enough that it doesn't happen.  The fuel and propane tanks will also sweat.  An insulated tank could be built and installed, but it would hold less water.
Jerry Whiteaker former owner 96 U270  36' #4831 Austin,TX-Owner Mods LCD TV w/front cabinet rebuild - LCD TV bedroom - Dual Central AC, either can cool coach w 30 amp - Skylights at roof AC openings - Drop ceiling for ducting of AC - Shower skylight white gelcoat/wood/epoxy frame - Air Springs/Shocks replaced - 2014 CRV - 8K Home Solar - Chevy Volt

Re: Water tank sweating

Reply #6 –
I agree on the insulation. That is the only think that I can think of that would solve the problem.  The humidity is so high and the water tank is cooler, thus the condensation.  At first I was thinking that this would only happen during the times when we have a humid warm front come thru right after a cold snap, but I then remembered all the days thru out the year where the temperature gets below the dew point in the morning and everything is wet. I can see where the tank could also be wet at that time.

There is foam insulation you can spray on. That might work the best.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Water tank sweating

Reply #7 –
Insulation is what I'm working on improving for sure along with some kind of ventilation. I know if we have a sweating problem that is weather induced others have the same thing happening.  Just so happened that the other day the temp was below the dew point and even with the tank drained as low as it will drain (our drain is about 1" above the floor) when we pulled the tank there was at least 1/2 cup of water under the tank. Even with the best sealant I like to check the wall to floor joints for cracks and adhesion . Keep the ideas coming

P & M

Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Water tank sweating

Reply #8 –
Question.....
Is there sufficient room around the tank to allow putting a "catch basin" under the tank with a drain hose thru the floor?
Similar to what is used in class 8 trucks to drain condensation away from the heater/AC units in dash/firewalls.
That would allow the water to exit the coach and insure a dry water bay..
just thinking
'02 40' U320t  4010WTFS Build 6036 1 slide
Motorcade # 17841
SKP 151920
Retired truck driver
 5 million miler
Still have itchy feet for travel

Re: Water tank sweating

Reply #9 –
What do you have to do to remove the tank?  And did you install a longer overflow hose so that water does not run down the back of the bulkhead? 
Jerry Whiteaker former owner 96 U270  36' #4831 Austin,TX-Owner Mods LCD TV w/front cabinet rebuild - LCD TV bedroom - Dual Central AC, either can cool coach w 30 amp - Skylights at roof AC openings - Drop ceiling for ducting of AC - Shower skylight white gelcoat/wood/epoxy frame - Air Springs/Shocks replaced - 2014 CRV - 8K Home Solar - Chevy Volt

Re: Water tank sweating

Reply #10 –
P & Mike.
Meant to ask the other day when you first posted how did you figure the Tank was "sweating" ? Was there a puddle of water that you noticed as I have never seen any obvious water by tank. I have never pulled it out to check under it so I guess you did see some either by the pump or the other side of Bay in the open. I always keep tank empty when not needing coach but we do not live in it Full time like you and others.
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Water tank sweating

Reply #11 –
Quote from: John Haygarth –
Meant to ask the other day when you first posted how did you figure the Tank was "sweating" ? Was there a puddle of water that you noticed as I have never seen any obvious water by tank. I have never pulled it out to check under it so I guess you did see some either by the pump or the other side of Bay in the open.
John,

We have caught the tank sweating on several occasions just by opening the service bay door and have seen the condensation. We have had a small puddle form from the water running down the tapered side and collecting on the floor behind the drawer we have.

Quote from: saddlesore –
Question.....
Is there sufficient room around the tank to allow putting a "catch basin" under the tank with a drain hose thru the floor?

Saddlesore,

Good idea but the tank fits wall to wall with a snug fit. There is room top to bottom to add an airspace/insulation underneath the tank but you are limited in height (about 1") as you have to contend with the cable tray that runs across the top.

Quote from: Jerry Whiteaker –
What do you have to do to remove the tank?  And did you install a longer overflow hose so that water does not run down the back of the bulkhead? 

Jerry,
Ours is pretty simple to remove. I will go into more detail when I get my tank repair done but here is a brief overview. Remove the 4 hinge bolts that the bay door moves on. The top 2 first then lay door over on a couple of milk crates then remove the bottom 2. Take door to store somewhere out of the way.  Remove the door pivot bracket 3 or 4 rolocks Yes they are in more places than just the bulkheads.  Remove the door seal and the trim strip along with the bottom door catch bracket that is in the way.  We have a drawer that has to be taken out in our service bay (4 bolts) and we don't have hose reels so that is a big help.  Then all that is left is go to the other side and remove the vent hose and 2 water lines. It is a big help to have the tank drained prior to removing these fill/drain lines. Now we just take a 2x4 from the passengers side and push the tank out on the drivers side.

Our over flow comes through our bulkhead all the way across our coach (over the truck arms) and dumps out just next to our wet tank drain.

Hope this covers every ones questions

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."