The leaves are changing color. Squirrels have stepped up their nut-hiding pace. Yep, winter is decidedly on the way, and if you’ll be letting your rig sleep for the winter, you’d best take good care to winterize your plumbing system. What kind of RV antifreeze should you use? What? You didn’t know there were different types?
Two kinds of different ingredients
No, we’re not talking about RV antifreeze versus automotive engine antifreeze. The latter is really toxic—pump it into your RV plumbing system and you’ll have serious, if not deadly, regrets. RV antifreeze is designed for potable water systems. It’s not toxic, although we’d avoid mixing with 7-Up for a highball. We’ve heard the taste is a bit on the unpalatable side.
So what kind of RV antifreeze should you use? It comes down to the basic working ingredient. Some folks will just walk into the RV supply store and ask for a couple of gallons of “the pink stuff.” Now, maybe that could be mixed with some whole cream…
Yes, we’ve been dwelling a bit on alcohol in the last couple of paragraphs. Some types of RV antifreeze do indeed contain alcohol. What sort? The somewhat non-toxic ethanol variety, grain alcohol. When ethanol “mixes it up” with water, the result is a lowering of the freezing point of water. That’s great for keeping the water from going solid, and expanding, and breaking your pipes. But there’s another contender in the RV antifreeze market.
That “other” active ingredient is technically a “double alcohol”—propylene glycol. It, like its competitor, ethanol, does its job by lowering water’s freeze point. Essentially the two different types do the same job. So what RV antifreeze should you use? We hear it coming: “If they both do the same job, use the one that’s cheaper!” Our bank account applauds you, but there’s more to the story.
One could leave a bad taste in your mouth
While ethanol-based RV antifreeze could technically be cheaper, come next spring, it could leave you with a bad taste in your mouth—literally. We’ve had RVers report that they used the cheap-o ethanol brands, but even after repeated flushing, found the taste left over in their water system was gaggy. Even if you just use your RV water for cleaning and toilet flushing, beware of two other possibilities. Reports show up that rubber seals can be adversely affected by contact with ethanol: Read that, “leaking.” And finally, ethanol fumes are flammable, so use it with care around flame or heat. Shut down motors and pilot lights when using the stuff.
And a virgin in the mix
So, boiling it all down, what RV antifreeze should you use? Is it “all for propylene glycol”? One manufacturer who made a brand of RV antifreeze based on propylene glycol touted its own product. It also warned against how some competing brands might use “recycled” products. Imagine RVers running out with buckets every spring, catching those precious drops of antifreeze, and shipping them back to some chemical plant for recycling! NOT! Rather, last winter (or earlier), when airplanes sat on the tarmac in a snowstorm, how did field crews keep them from icing up? They sprayed them with aircraft antifreeze, made with, of course, propylene glycol. Rather than letting that antifreeze go, some airports ship the used product back to a recycler. That, said the manufacturer, could lead to all sorts of nasties in RV antifreeze.
We tried to track down more information about this. Some “RV websites” tout various brands that supposedly contain “virgin” propylene glycol (PG). Maybe yes, maybe no. Some claimed Walmart’s SuperTech RV and Marine antifreeze was 100% virgin. A quick look at the product’s safety sheet positively states it does contain propylene glycol—but no statement as to how “pure” that is. But that same product ALSO contains ethyl alcohol! Look as we might, we could find only ONE RV antifreeze that actually claimed to use 100% virgin PG. That’s the Star Brite brand, but sadly, it doesn’t appear to be widely distributed.
Does it matter? We’re not quite sure. The company that ballyhooed its virgin purity didn’t explain in any great detail as to what might be in recycled PG that was so awful.
Here’s what some brands contain
Here’s a chart showing some brands of RV antifreeze, and what their “active ingredients” are.
What do we use? Ha! We don’t worry about taste or plumbing deterioration problems. When we winterize, we use air pressure to blast water out of our pipes. What little antifreeze we use goes down the plumbing drain P-traps. I promise you this: We’ve never tasted what comes out of there!