Automotive vs RV antifreeze

[Russell E Johnson]

Can I use regular automotive antifreeze in the black and gray water tanks and sink traps or must I use the RV antifreeze?  I am in NE AR and only blow out the lines to winterize the water lines in our MH.

[Rich Thomas]

Wouldn't that be a bunch more costly not to mention the possibility of poisoning a pet or a neighbors pet. Just saying!

[Russell E Johnson]

so are frozen/broken pipes.  I have not been able to locate any un-diluted pink RV antifreeze that I used to get to winterize our TTS.  I am worried that this pre-diluted junk is not going to be strong enough when added to the water already in my P traps to keep them from freezing.

[Russell E Johnson]

OK, RV antifreeze has changed since the last time I looked at it.  I bought some from Walmart and I see it is good to -50 degrees.  Last time I looked is was only -10 or -20 degrees and mostly water.  I feel better about using it.  Thanks all for your input.

[John Demarrais]

The RV antifreeze you see in places like Walmart and Home Depot ARE diluted. That minus 50 rating is only when used in pure strength. Mix it 50/50 and it will freeze at 10 degrees above F. Keeping it pure strength is not always possible with plumbing.   You dump some in a trap that has water in it, and unless you dump in an awful lot of antifreeze - it gets diluted and will freeze at a higher temp. Same if you run some in your lines and there's some trapped water in there.  Auto antifreeze can be mixed with 40% water and be good to 50 below 0 F.  Try that with that so-called "minus 50" stuff and your pipes will freeze.

 The better RV antifreeze is rated to 100 below in pure strength.  That's what a plumber or heating tech will use when filling heating pipes in a house with hot-water heat. Non-toxic and $12 per gallon.  Hercules Cryo-tek-100,  Camco 35116 Boiler Antifreeze, No-Freeze concentrate, etc.  Mix it 50/50 with water and it's good to 30 below F.

[Russell E Johnson]

So, if I understand you correctly, I was right in my thinking to go with automotive antifreeze in the p-traps and holding tanks instead of the RV antifreeze as I cannot locate the -100 degree stuff I used to use.

[John Demarrais]

As far as freeze-protection, yes.  But automotive antifreeze is highly toxic.  Pretty much illegal to dump it down drains or on the ground.  That makes it not a great choice for protecting plumbing anywhere.

[John Demarrais]

I'm not saying you need it - but if you want non-toxic antifreeze that is much stronger then that diluted so-called "-50" RV crap, there are many places to buy including Home Depot and any plumbing or building supply place.  Heating system or swimming pool anti-freeze. 2 to 3 times stronger then that watered-down "
-50" RV stuff that is only good to around 10 above F when mixed with water.

Camco swimming pool non-toxic anti-freeze is $11 per quart at Home Depot. Here's the description off the label:

"Concentrated formula saves on freight. This new Pool Antifreeze gives you great winter protection at a lower price. Our antifreeze is concentrated so 1 quart mixed with 3 quarts of water will make 1 gal. of antifreeze that will protect pool plumbing down to -40° F. Want even lower temperature protection. Add less water. Comes with a dilution chart, so you can make the strength you desire. We recommend -40° F to be safe. Concentrated antifreeze is totally safe for swimming pool use and non-toxic. Use one gal. for every 10 ft. of 1.5 in. pipe. Safe for all types of pool plumbing. 100% Propylene Glycol."

[Russell E Johnson]

Thank you for the clarification