How to dewinterize a simple water system?

[sunnyone]

I’ll be dewinterizing our 2020 Scamp soon for the first time. It’s a pretty basic water system - just a freshwater tank with a hand pump at the sink, a city water connection to a smaller faucet, and a greywater tank. Last fall I blew out as much water as I could and put a gallon of pink antifreeze in the tank and pumped it through the big faucet. The city water never got used last year so just left that alone.
The Scamp is in our garage, off the alley that runs down our city block. So, if I drain the antifreeze in the freshwater tank into a pan, what do I do with the used antifreeze?
Then just fill the tank and pump some water through the faucet and empty out the tanks?

[Jon in AZ]

The pink stuff is non-toxic, so you can put it down the drain. I would partially fill and drain the fresh tank a couple of times before pumping through the line to the sink. Lowering the tongue will give a faster and more complete drain. If you don't like wasting all that precious water, collect it in a basin underneath and water your garden.

[thrifty bill]

While many call it antifreeze, fortunately its different than traditional antifreeze. Ethylene glycol (traditional antifreeze) is poisonous. Propylene glycol has similar properties without the hazards, is a common ingredient in many food products and is in most RV antifreeze products.

Double check the label, but I have only seen propylene glycol in RV antifreeze.

[sunnyone]

Originally Posted by Jon in AZ

The pink stuff is non-toxic, so you can put it down the drain. I would partially fill and drain the fresh tank a couple of times before pumping through the line to the sink. Lowering the tongue will give a faster and more complete drain. If you don't like wasting all that precious water, collect it in a basin underneath and water your garden.

Thank you Jon. Thanks just the kind of specific detail I was hoping for.

[sunnyone]

Originally Posted by thrifty bill

While many call it antifreeze, fortunately its different than traditional antifreeze. Ethylene glycol (traditional antifreeze) is poisonous. Propylene glycol has similar properties without the hazards, is a common ingredient in many food products and is in most RV antifreeze products.

Double check the label, but I have only seen propylene glycol in RV antifreeze.

No worries Bill. It’s the pink rv antifreeze.

[gordon2]

Originally Posted by thrifty bill

While many call it antifreeze, ...

I saw some RV Antifreeze for sale at the local Habitat Re-Store a while back but it had no price on it so I just went to the check-out with my other items. A guy in line behind me had some of the antifreeze so I got out of line and waited to see what he had to pay for it. The clerk had to check on the price and that delay gave me a chance to ask the guy if he did much camping. He said he didnt camp. I thought for a few seconds because I didn't want to insult him, but then took a chance and said, "You do know that antifreeze is not for motor vehicles, right"? He replied, "It's not? Really? So I explained to him how it is a non-toxic treatment for water systems in campers. He decided to not make the purchase. I also passed on it since the price they finally came up with was more than the local department stores charge.

True story.

[Jann Todd]

Originally Posted by gordon2

I saw some RV Antifreeze for sale at the local Habitat Re-Store a while back but it had no price on it so I just went to the check-out with my other items. A guy in line behind me had some of the antifreeze so I got out of line and waited to see what he had to pay for it. The clerk had to check on the price and that delay gave me a chance to ask the guy if he did much camping. He said he didnt camp. I thought for a few seconds because I didn't want to insult him, but then took a chance and said, "You do know that antifreeze is not for motor vehicles, right"? He replied, "It's not? Really? So I explained to him how it is a non-toxic treatment for water systems in campers. He decided to not make the purchase. I also passed on it since the price they finally came up with was more than the local department stores charge.

True story.

With people like that you are not sure if you should buy a used vehicle sometimes. He's lucky you spoke up.

[Raspy]

Propylene Glycol is an excellent corrosion inhibitor and is used in solar hot water systems that reach very high temperatures. I've been adding it to hot water systems for 40 years, to stop corrosion and prevent freezing. I see no reason why it would not be just fine in a car system, as long as the ethylene was flushed out first.

[AC0GV]

Originally Posted by Raspy

I see no reason why it would not be just fine in a car system, as long as the ethylene was flushed out first.

It will freeze, but only to the consistency of a slushy. That means it will not flow in the engine and heater. It just will not expand and burst your plumbing when it freezes.

https://www.youtube.com/watch?v=4g6Z49jx4tQ

[Darrell in Al]

And could jell or turn to slime if mixed with auto antifreeze. Scary thing is look at low cost "ice cream" ingredients it's in a few of them the RV version.
Just flush it out a few times and then sanitize the fresh water tank your good until fall.