Grey water tank - insulation vs antifreeze

A_Bus_Called_Quest · 09-27-2021, 08:00 PM

Skoolie Fam!
Reading over the threads on how to keep the grey water tanks from freezing got me wondering - if there is grey-tank antifreeze, do I even need to insulate?

I was thinking of building a box from 15/32plywood (i have some left over) and lining with 1" pink XPS foam. As mentioned - now I'm wondering if I even need to go through the trouble +added weight to the suspension mount (superstrut).

How is everyone's experience with antifreeze in the tank?

If the antifreeze works - is a bare tank, suspended from the frame OK? Or, do I need to protect it with something anyway?

As always - thank you for your help on this wild ride, we're going full-time in aprox. 46 days and I definitely wouldn't have made it this far on the bus without y'all

Finger's crossed - we'll have this baby done on-time!

Danjo · 09-27-2021, 09:02 PM

Well, I’m a fair weather flatlander who hadn’t considered this in the build. I think a lot of people on this forum who have thought about it have done insulation, heating pads or both.

I have no room for insulation in my build and I don’t have the electrical infrastructure to run a heater for that. So for me, if I find myself in freezing temperatures, it has to be antifreeze.

A_Bus_Called_Quest · 09-27-2021, 09:43 PM

Quote:

Originally Posted by Danjo

Well, I’m a fair weather flatlander who hadn’t considered this in the build. I think a lot of people on this forum who have thought about it have done insulation, heating pads or both.

I have no room for insulation in my build and I don’t have the electrical infrastructure to run a heater for that. So for me, if I find myself in freezing temperatures, it has to be antifreeze.

We're on the same page here Danjo - we plan to stick to fair weather and have very little room for insulation on our kitchen sink tank.

Do you have anything covering your tanks - or - have you had any problems with road debris damaging your tanks?

Aside from a promised trip to my dear mother in Iowa for Christmas this year (it has been a few years, I owe it to her - plus I want to show off the bus), we plan to chase fair weather and only plan to be in cold weather for December and early January as we head south from Iowa to warmer weather.
I think we'll be OK with antifreeze as a backup when we find ourselves in stuck in the cold - I'm crossing my fingers for a late mid-west winter this year

Thanks for your input - you've been a huge help getting this build finished on time!

Danjo · 09-27-2021, 10:05 PM

I did what you are doing with unistrut. I cut a piece of 16ga steel sprayed with waterproofer as a liner for the bottom of the tank.

s2mikon · 09-27-2021, 10:13 PM

If you are talking about RV Propylene Glycol antifreeze with the pink dye it is only about 25% Propylene Glycol. You will be diluting it with grey water so you will have to use a lot of it. If you go to your farm supply store and get Propylene Glycol for cattle it is 100%. It is for treating ketosis in cattle. With this you won't have to use as much to get freeze protection. They also have horse de-wormer too.

turf · 09-27-2021, 10:13 PM

i survived 2 colorado high country winters in my bus. the waste tank is exposed, uninsulated, and i have heating pads on it.

as long as the temp is above freezing part of the time, dumping is ok. frequently my days were in the forties, and the nights were 0.

issues happen when it got cold for a long time. my tanks have about 2 weeks capacity.

antifreeze works fine in the tank but dilutes a lot. the freezing point is much different when its used for 50 gallons of water. iv'e used ice melt too.

get there on an empty tank and you'll probably be fine until you get to warmer climates. when my waste tank would freeze, nothing breaks.
everything is ok until it melted. be sure to keep the heat on inside your rig 24/7 because interior plumbing freezing does cause damage.

i would not bother with antifreeze for the waste, unless you were travel into some extreme cold.

Danjo · 09-27-2021, 10:19 PM

Quote:

Originally Posted by s2mikon

If you are talking about RV Propylene Glycol antifreeze with the pink dye it is only about 25% Propylene Glycol. You will be diluting it with grey water so you will have to use a lot of it. If you go to your farm supply store and get Propylene Glycol for cattle it is 100%. It is for treating ketosis in cattle. With this you won't have to use as much to get freeze protection. They also have horse de-wormer too.

Thanks that’s a great tip

A_Bus_Called_Quest · 09-27-2021, 11:59 PM

turf - good to hear you haven't had any problems, eases my mind a little bit. Yours and Danjo's experience combined with s2mikon's cattle glycol and I think we'll make it out just fine ;)

Good idea on the sheet metal base for the water tanks Danjo - I have a ton of ceiling sheet metal left from the bus that should work as a sturdy base for the tanks.

WIbluebird · 09-28-2021, 06:19 AM

I don't plan on using my plumbing in the winter time. I will drain all my tanks at the end of November so zero need for tank insulation for me.

Danjo · 09-28-2021, 06:29 AM

Can a good quality HDPE RV tank burst from freezing? I worry more about the ABS.

turf · 09-28-2021, 07:16 AM

my waste tank is abs and it takes freezing just fine.

i installed heating pads to thaw the big fudgsicle when necessary.

to check whether or not to turn on the heating pad, i would use a hammer and tap the tank. if the wall is bouncy, the tank is fine, if its rock hard, the tank is froze.

the heating pad doesnt thaw extreme cold. you still need sunshine and mother nature.

i did blow out my interior plumbing last week. i can flush with bottled water, if i use the camper in the winter. the plumbing waste side is frost free. hepvo valves are the bomb!

sportyrick · 10-02-2021, 03:20 PM

I drain my tanks and blow out all my water lines around November but we take a Christmas trip with a dozen or so people so we keep a jug of RV antifreeze next to the toilet to flush with. Never had a problem, not that expensive for just a couple of days, of course no showers in the bus.

A_Bus_Called_Quest · 10-02-2021, 03:23 PM

Quote:

Originally Posted by sportyrick

I drain my tanks and blow out all my water lines around November but we take a Christmas trip with a dozen or so people so we keep a jug of RV antifreeze next to the toilet to flush with. Never had a problem, not that expensive for just a couple of days, of course no showers in the bus.

No showers in the bus in the winter because of freezing? Do you think the antifreeze would help this also? We're using Hepvo valve on the shower, so I'm not as worried about the pipes freezing, maybe keep a jug of antifreeze in the bathroom to pour a small amount down the drain after each shower to flush out the pipe. . .

flattracker · 10-03-2021, 12:32 AM

Years ago when we had our first motorhome we took a trip at Christmastime and stopped at the KOA in Klamath falls for the night. Our holding tank was full and would not dump when I connected the hose and opened the valve. When I took the gate valve apart I discovered a sh** slurpy in there. After pans of hot water all freed up but do not ever wish to do this again. I think the cattle antifreeze woulds be a good idea in cold country. Out here the temps can get to -40 degrees F. I will not have any water in any part of the bus when it gets cold out. I learned the hard way.

cadillackid · 10-03-2021, 08:43 AM

I think all this talk of cold and freezing is depressing.. I'l just drive to Miami and stay in beachfront resort hotel and not think about frozen stuff unless its a margarita or a frappucino

incubus · 10-03-2021, 09:54 PM

Build insulated box, put a water bed heater under tank. Done .

A_Bus_Called_Quest · 10-05-2021, 01:49 PM

After getting in there with the unistrut and my plumbing, I ended up not having enough room for an insulated box on our sink tank, so I skipped on both (sink and shower)
We only plan to be in cold weather for about a month, and will be with family the whole time so we can shower / sink stuff indoors. I will keep the heat on to prevent interior from freezing, and we will be sleeping in the bus so we can keep an eye on everything.

kidharris · 10-05-2021, 03:16 PM

Quote:

Originally Posted by incubus

Build insulated box, put a water bed heater under tank. Done .

Done until you don't have any electricty

incubus · 10-05-2021, 09:20 PM

True no electric no heat ,didnt sound like he was boondocking. I've insulated the compartment and put furnace duct in there too. Water bed heater works best. Low draw

turf · 10-06-2021, 12:17 AM

i actually have 2 heating options.

the stick on heating pad in the above picture on the bottom of my tank is a 12v heating pad.

for when im plugged in to shore power, i have 120v heat tape that wraps the tank and pipes.

around zero, neither works, they just don't radiate enough heat. you can fill your tanks in zero weather, you just can't drain them.

take advantage of warmth when you get it. drain a half full tank on a warm day. just once, in my 2 Colorado winters, i had to drive down to Albuquerque to thaw out. we, were in a long January deep freeze and my tanks were full and frozen.

you'll be fine, and if not, it'll expose your weak points. good luck

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