Using Heat Cable to Protect Gray/Black Drain Pipes (T@B 400)

[Deleted User]

Hi, this is a little bit difficult to explain, but here goes.  I'm planning to insulate my grey/black dump lines so I can extend my camping season a few weeks on each end of the season. I don't plan to camp in frigid cold temps.  I'm also planning to install tank heating pads on my grey and fresh water tanks, but my question today only relates to the dump pipes outside the camper.  

So, I bought a 6ft "Wrap On" heating cable and I got a piece of 3 1/2" diameter EPDM Rubber pre-formed pipe insulation.  Unfortunately, after receiving the heat cable the directions SPECIFICALLY say not to use "FOAM pre-formed pipe insulation."  It doesn't speak to the RUBBER preformed pipe insulation which is much more heavy duty than the foam.  I'm assuming their instruction would include the RUBBER preformed pipe insulation, but maybe not?  I tried calling the Wrap On company but for obvious reasons they are not open.   The instructions say to only use fiber glass insulation.  Well, that won't work in this application because the pipes are outside in the weather and I intend for the installation of the cable to be mostly permanent. 

I guess my question is, does anyone have any knowledge about why it wouldn't be safe to use the EPDM rubber insulation over the wrap on heat cable?  The rubber insulation is designed to take temps up to 300 degrees, so that can't be the problem.  Would it be that the foam or rubber insulation holds in too much heat causing the cable to melt the pipes or start a fire?  

My plan was to clean the pipe, then wrap it entirely in heat conducting aluminum HVAC tape, then wrap the cable around both the grey and black pipes (crossing over the dump valve in the middle) securing the cable with electical tape and some velcro straps, then putting the EPDM rubber pipe insulation over everything and securing that with some heavy duty velcro straps.  

If its not safe to use the rubber insulation, can anyone recommend something else that is water and travel proof?  

Or, what if I just wrap the pipe in the metal HVAC tape and then put the rubber pipe insulation on without a heat source?  Would that give it any worth while protection at all? I guess it would only keep wind off of it.  

Sorry this is so long! I put so much thought into this project and I thought I had it all figured out only to hit a road block.

Thanks!!

falcon1970

@TabbyShack
If you are talking about insulating the dump lines downstream of the dump valves there should be no need to do that.  There should not ever be any water downstream of the dump valves--and thus nothing to freeze and expand.  If you are going to heat the gray tank the heat will migrate through the liquid in the drain pipe.  The black tank is inside the trailer so it will be protected and the temperature of the liquid will also even out throughout. 

[Deleted User]

Well, I'm thinking of the lines "upstream" of the valve.  The black and grey water that is waiting just behind the valve to be released.  But that's right, the grey water in the dump line waiting behind the valve would be heated by the pad, so if I did put the rubber insulation on that section, that should help retain that heat for awhile. I'm attaching two pics of the black pipe and grey pipe that are exposed outside. 

The black water free flows down the external section of 3" pipe and waits at the dump valve.  I know the black tank is inside the  camper but that 8" section of 3" pipe that you can see outside, that is full of black water I believe? This first pic is the 3" black pipe that is fully outside the camper. The top left is the floor of the camper. The dump valve is in the upper right of the photo.  The second pic is the 1 1/2" grey pipe and again the grey water would be waiting in that section of the pipe to be dumped. 

I'm kind of thinking now that if I just put the rubber insulation around these two pipes without the heat cable, that it should be enough since I don't plan to do any deep freeze camping.

What do you think?

falcon1970

That sounds logical to me.  Even if you are camping in temps below 32 degrees the liquid won't freeze immediately.  Even out in the air it will take several days of below freezing temps to affect it--depending on how much below freezing the temp is.  Insulation will delay that even longer.

[Deleted User]

Great! Very helpful to have another person chime in on stuff like this.

Amazonica

Hi @TabbyShack. I would be interested to see how you resolve this please. I have wanted a simple solution to camp and travel in freezing temps, without altering the Alde or battery drain while boondocking. Your insulation idea seems perfect for what I'm looking for. Also DIY since, you know, money...

[Deleted User]

Hi Amazonica. I would be happy to share what I've pulled together so far.  I also drew a diagram I can share. I will be in touch soon. 

gbart

@TabbyShack
Did the EPDM rubber insulation work as planned? I am in the middle of adding heat pads to the tanks, outside pipes and dump valves. But would rather eliminate the battery drain if pipe insulation works

Denny16

Where did you get the rubber pre-formed pipe insulation?  I would be interested in this also.  

Cheers

[Deleted User]

Hi. Let me find my notes and I will post info soon.

Pancho_n_Lefty

May not be what you're looking for but we just put some RV antifreeze (same stuff used for winterizing by the dealer) in the black tank/grey tank when we go up to camp over night when skiing in the winter. If shower is needed (long term stay) we just heat water on the stove and use a gravity shower in the bathroom for showering (don't use white tank/sink).  Never had a problem with smells or the Happy Camper not working.  Been in ice storms too with no problem (1/4" ice coating camper and no ill effects on plumbing).

Not elegant, but it is simple!

Cheers!

Tampakayaker

We lived in NY in a mobile home.  The heat tape along with the wrap around fiberglass insulation strips were wrapped around the incoming metal water line.

The drain line (only one) was wrapped in insulation.  Of course the MH wasn't moving.

I think if you put the rubber insulation or wrap the drains with the fiberglass you will be OK.

I think the insulation we used was like wide tape that you spiraled around the pipes and overlapped the edges. 

[Deleted User]

Hi gbart and Danny16, so I found out during the research phase that you can not cover the heat wrap cable with the EPDM preformed rubber pipe insulation.  It insulates too well and can cause damage to either the pipe or the cable.  So, I decided to just wrap the drain pipes with a 6ft heat wrap cable, starting at either the bottom of the camper where the black pipe comes through the camper floor, or starting on the right side where the grey water pipe starts, and wrapping all along the pipe from one side to the other to include as much of the dump valve area as possible.  This would work for awhile, but I wouldn't rely on it for longer periods of below freezing temps. The heat cable I decided on is below from Amazon.  I also bought some 2" wide velcro straps, so I could easily install it and remove it when I wanted to.  If you are staying put for longer periods, you could just wrap with the traditional pink/yellow fiberglass insulation. That is safe to use with the heat wrap cable.  Sorry these are not product links. You will have to search on Amazon using this info:

Wrap-On Pipe Heating Cable - 6-Feet, 120 Volt, Built-in Thermostat, Low Wattage - 31006

Reusable Cinch Straps 2" x 20" - 6 Pack, Multipurpose Strong Gripping, Quality Hook and Loop Securing Straps (Black)

This is the pipe insulation I bought, but the manufacturer of the heat cable said it is not safe to use. 

3-1/2" x 6 ft. EPDM Pipe Insulation, 3/8" Wall

The other thing I had planned to do, is install an "Ultra-Heat" heating pad to both the gray and fresh water tanks, and then wrap in bubble insulation wrap. Ultra Heat sells an AC only pad that just plugs into an electrical outlet so you don't have to deal with doing any electrical installation.  I haven't done that yet as it was harder to get under the camper and work than I anticipated, so I'm going to to take it to a repair place in a couple of weeks and have them install it for me while on a lift. 

gbart

Thanks @TabbyShack. I'm still toying with a couple of your ideas. Will update when I;m done.

[Deleted User]

It takes a village to raise a T@B :-)

Please keep us updated on what you end up doing.