How to seal holding tank?

[Axion]

Well, I finally decided to remove the coroplast (plastic cardboard) underbelly on my Wildcat. I had to use the rv last winter and, surprise surprise, had freeze up issues. My mission is to make this unit 4 season capable! So, once I started tearing out the coroplast, I started to find things that will keep me from ever purchasing another Forest River product.



First up was the joke of insulating the holding tanks. I'm not sure why anyone at Forest River believes that a 1" piece of fiberglass insulation between the tank and the coroplast will do any good at all! Especially when the rest of the "basement" is left bare. Next up was the 4 to 6 foot chunks of wire, both 14 gauge used for running 12 Vdc items and 14/3 household wire. What really made me wonder was the half full aerosol can. The label had rubbed off after five years of rolling around and I was too chicken to try it out.



Anyhow, I am making some changes to how the plumbing is routed and had a question about how the holding tanks are sealed. The abs fittings that come out of all three tanks are held in place with 2 band clamps and have some sort of white stuff oozing out. Does anyone know what the white stuff is? It is still soft and pliable, even after 5 years. Is it some sort of rv specific sealant?



Thanks in advance for any and all help, I'll be back when I'm ready to figure out how I'm going to heat the space.

 

[RustyJC]

The abs fittings that come out of all three tanks are held in place with 2 band clamps and have some sort of white stuff oozing out. Does anyone know what the white stuff is? It is still soft and pliable, even after 5 years. Is it some sort of rv specific sealant?

Wow. The way you describe it, this could be Dicor self-leveling sealant that's normally used on EPDM roof membrane material. Hopefully someone more knowledgeable about Forest River's construction methodology than I will come along and advise that it's a magic ABS sealant, but I've never seen any in my household plumbing project experience that looks like what you describe.



Rusty

 

[EricBu12]

Robin.
Man! you have done an undertaking!. . I am afraid to take my 36' of coroplast off. . I have peeked in the access holes and have seen the joke insulation. . had that route on the upper insulation in the nose cap and rear wall of the pantry next to the fridge. . melted chocolate. . had to put in blocks of insulation under the bathroom/bedroom floor to insulate that from the heat of the generator and the hot day coming through the thin storage doors..... my water tank seems to be drooping as well from the weight of the water. . need to put a cross brace under it... . golly, plastic can't support water on it own?. . lol.

I would use styro-foam blocks with the expando foam for glue to insulate the tanks, . . then seal it up real good with a better plastic cover. . If I drive in the rain, water gets into the cover and I poked a pinhole at the bottom of the droop by the water tank and water runs out. . .

So mine is a Keystone Raptor Toy-Hauler and unless you buy a very high priced RV, you will get crap construction on alot of them. . Just fix it as it should be fixed and keep on RV'n.

 

[Axion]

Rusty;



Now that you mention it, it does look similar to the stuff on the roof, although whats on the roof seems to be a little more solid. I'm going to talk to the service guy at the local rv dealer and see what they have to say.



EricBu12;



Yeah, it has turned out to be quite the project. But now that its started..... The galley, grey and black holding tanks seem to be keeping thier shape relatively well, as they are sloped towards the drain. The fresh tank though has drooped at least 2" in the middle. Mine has "ribs" molded into it that were probably meant to help maintain the shape. Too bad it didn't work out that way. The only thing that scares me about putting in a cross brace is having the brace rub through the tank over time.



I plan on using 2" rigid foam insulation to enclose the basement this time. I will seal all the seams and then use the DIY truck bedliner (Herculiner, etc) to protect the insulation from road debris.



Then there's the question of keeping the basement area heated. I could mount some small electric heater to the structure or I was thinking about creating another branch off the furnace. Branching the furnace might be more work than I have time for. Mounting an electric heater should keep the basement above freezing. The tanks themselves are getting the "stick on" heaters so I don't need the area heater to keep all the liquid warm as well. I'm also moving all water lines to inboard of the main frame rails to the new warm zone.



I was looking at "upgrading" to a Raptor 3600RL but the RV Consumer group doesn't rate the 3600 RL much better than my Wildcat. I would love to buy a New Horizons unit but I have not won the lottery as of yet.

 

[GCroyle]

Axion,



Back to your original question:



HOW TO SEAL HOLDING TANK?



Buckets and buckets of Atomic buffalo wings, lots of south of the border chow combined with an evening campfire and a bunch of TDR members.



That should seal the tank just fine.

 

[Bill Stockard]

Well, I finally decided to remove the coroplast (plastic cardboard) underbelly on my Wildcat. I had to use the rv last winter and, surprise surprise, had freeze up issues. My mission is to make this unit 4 season capable! So, once I started tearing out the coroplast, I started to find things that will keep me from ever purchasing another Forest River product.

I had to drop one side of the belly pan on our '97 Hitchhiker II that we previously owned and came to the opposite conclusion. By the way, the belly pan was NOT made from the stuff you describe.



Bill

 

[JLEONARD]

I would use 5200 to seal the fittings. I'm a boater and I almost always have some around and it is my sealant of choice.

 

[Gonzo 1066]

I have seen a pliable sealant used in the plumbing to allow the gate valves to be replaced. If they are glued in place the valve is nearly impossible to remove.

 

[LandShark]

I would use 5200 to seal the fittings. I'm a boater and I almost always have some around and it is my sealant of choice.

5200 is great stuff, but very permanent (and not UV resistant; which would be OK under your rig).

The sealant you are talking about is a strip caulk (comes in rolls, with a paper backing) similar to plumbers puddy. Used in many RV's to seal windows, seams, and yes, sewage systems. Any RV shop has it.

 

[Axion]

All;



Sorry for the delay in getting back to this. Been a long week at work with very little internet time.



I have never heard of "5200" and will have to look into it. The stuff on my tanks is definitely the same as the roof sealant. The local rv service guy said the tank will actually flex a little and the two band clamps should compress it enough to complete the seal. He said they rarely have leaking issues with this style of tank. I guess the manufacturer had some dicor laying around and just wanted to make sure.



Thanks again for all the input. Its turned out to be a bigger job than I thought, but it'll be nice to not have to worry about freezing up come next winter.

 

[Mikey-KE7LBB]

As far as heating the space under the floor goes, you could cut a hole in one of the heating ducts near the tanks and it should keep the space under the floor warm. Only drawback is that the furnace may run longer, but at least the piping and tanks won't freeze.

 

[Wertles]

I was just reading the useless owners manual that came with my camper and when i got to the section on the fresh water holding tank it was very specific NOT to add additional bracing to the tank. It states that the tank is designed to expand down when water is added and by adding braces under the tank may lead to the tank expanding up resulting in floor damage. You might want to check with the manufacturer to see if you have this type of tank.