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Wic · 02-12-2021, 08:36 AM

Long story about why I'm asking, but...local vendors are sold out of rv/marine water system antifreeze...any ideas about a homemade antifreeze?

Cooperhawk · 02-12-2021, 08:40 AM

With our old RV I winterized with Vodka. That's right, Vodka. I bought the cheapest brand on the market and pumped it into the lines. It prevents freezing as well as sanitizing the lines, and in the Spring, if you are so inclined you can have a de winterizing party.

It also does not leave that awful taste of anti freeze.

Gary RVRoamer · 02-12-2021, 08:44 AM

Any kind of non-poisonous alcohol makes a decent antifreeze for water lines. Ethanol, not methanol! And not the "denatured" stuff either - you can't drink that. Mix with water to get the desired level of freeze protection. 35% ethanol in water gets it down to about 0 F.

This freeze table shows percentages:
https://www.engineeringtoolbox.com/e...ter-d_989.html

If you can find a source for propylene glycol, you can use that instead. It's potable and mixes well with water.

Cooperhawk · 02-12-2021, 08:48 AM

Vodka! KISS!

Dav L · 02-12-2021, 09:20 AM

Most important is to use 40psi of compressed air to blow out all the lines if the rig will be in the cold without heat. Then follow up with whatever antifreeze you find (that is safe for fresh water systems).

Winemaker2 · 02-12-2021, 09:52 AM

Alcohol based AF is one of things that more may not be better. The one year I used alcohol based AF Both water inlet solenoids on our washer failed. One I would say coincidence but both at same time was more than coincidence IMO.
I've used propylene glychol based AF since and no problems.
If it were me and I was forced to use a alcohol I would blow out shortly after.

Cooperhawk · 02-12-2021, 02:57 PM

I used Vodka from 1996 to 2012 in our Airstream Motor Home without any problem of any kind. Our present Journey only needs to be blown out so I don't use it anymore.

bmcgc · 02-12-2021, 03:10 PM

Is Amazon also out?

US1 · 02-12-2021, 05:12 PM

Sorry I cant offer any more help, but have you checked Menards? They carry RV/Marine AF year round.

As to an alternative, I've heard of guys using windshield washer fluid as a last resort.

Ray,IN · 02-12-2021, 05:30 PM

Quote:

Originally Posted by Gary RVRoamer

Any kind of non-poisonous alcohol makes a decent antifreeze for water lines. Ethanol, not methanol! And not the "denatured" stuff either - you can't drink that. Mix with water to get the desired level of freeze protection. 35% ethanol in water gets it down to about 0 F.

This freeze table shows percentages:
https://www.engineeringtoolbox.com/e...ter-d_989.html

If you can find a source for propylene glycol, you can use that instead. It's potable and mixes well with water.

Tractor Supply sells propylene glycol. One gallon is diluted to make several gallons of solution.

FYI it is an ingredient in Fireball Whiskey and most pre-packaged prepared foods.

Unplanned Tourist · 02-12-2021, 05:56 PM

Quote:

Originally Posted by Wic

Long story about why I'm asking, but...local vendors are sold out of rv/marine water system antifreeze...any ideas about a homemade antifreeze?

Do you have a still?

Otherwise, you are going to have to buy something, so after a good blow-out, do like some others have suggested, and use the cheapest 40% (80 proof) booze you can find.

I never use anything, just a real good blowing out, including the ice maker, water heater, outside shower, and washer/drier. It's -25C (13 below 0 F)in the mornings here these days, and knock on wood, I have never had a problem in 16 years.

BTW, you can use regular car antifreeze in your P traps. Just don't get caught putting it down the city sewer, it's not too good for fish.

n2zon · 02-12-2021, 06:16 PM

Quote:

Originally Posted by Dav L

Most important is to use 40psi of compressed air to blow out all the lines if the rig will be in the cold without heat. Then follow up with whatever antifreeze you find (that is safe for fresh water systems).

The AquatHot manual says not to do this. Without a hydronic heating system, though, I agree.

Dav L · 02-12-2021, 06:53 PM

Quote:

Originally Posted by n2zon

The AquatHot manual says not to do this. Without a hydronic heating system, though, I agree.

Where does it say that?
What it says is that you should always use RV winterizing solution.
That's NOT saying don't also blow out the water with air.

Blowing out the water is still better than doing nothing (the OP states he can't find antifreeze).

The reason Aquahot says that is that it is difficult to get all the water out just using air. The water has a tough time going around and around all the coils and out. If using one spurt of air, the water will climb the coil. If the air is removed, then the water will sag back down to the bottom and collect and if left there, freeze, expand, and break the coil walls.

But using repetitive and long cycles of air has higher odds of removing it all. Antifreeze is just more thorough with higher odds of protecting the coils.

That's the mechanicals.

n2zon · 02-13-2021, 05:27 AM

Quote:

Originally Posted by Dav L

Where does it say that?
What it says is that you should always use RV winterizing solution.
That's NOT saying don't also blow out the water with air.

Blowing out the water is still better than doing nothing (the OP states he can't find antifreeze).

The reason Aquahot says that is that it is difficult to get all the water out just using air. The water has a tough time going around and around all the coils and out. If using one spurt of air, the water will climb the coil. If the air is removed, then the water will sag back down to the bottom and collect and if left there, freeze, expand, and break the coil walls.

But using repetitive and long cycles of air has higher odds of removing it all. Antifreeze is just more thorough with higher odds of protecting the coils.

That's the mechanicals.

Well, you could be right, but experimenting to find the boundaries of "not long enough" and "long enough" could get really expensive. I'd still advise against it for a coach with an AquaHot. I do understand the OP has a local availability problem. I'd look around more, order some, or make it from GRAS ingredients, and just leave the system on at the lowest temperature the thermostat let me set until it arrived.

Anyway, to answer your question, Appendix F in the AHE-450-DE4 Service Manual has a black-bordered WARNING box in the right column under Step 6 on p. 112, which says:

"An FDA approved “GRAS” rated winterization antifreeze must be used. YOU CANNOT BLOW DOMESTIC WATER COIL OUT WITH AIR TO WINTERIZE AQUA-HOT." (Emphasis theirs, not mine.)

This is repeated in their FAQ, here: Aqua-Hot - Frequently Asked Questions

On a related topic, while I don't recall that the OP mentioned a washer, blowing one of those out might be impossible, because some low-lying spaces in the pump and filter might not be in the airflow.