Year old anti freeze

[WLYBGR]

Hello; I have got leftover anti freeze is an unopened jug,last years.Is it still good.Any way of checking it's strength? thanks

[J Mac]

Pour some in to a shot glass, stick in freezer and see what happens.

[Jim Bennett]

I use it from many years back with no problems. Did I get lucky?

[padlin]

I wouldn't hesitate to use it, but then I just run it in and blow it out. I've been told it turns to slush when frozen as opposed to staying 100% fluid.

[Iowa Dave]

I buy six gallons at a time an use it till its gone. Sometimes three or four years. In my turf sprayer I recapture the cycle through and use it again the next year , just adding a little to what stays in the pump and lines and is lost in the flush out in the spring. No worries to fifteen below F
Dave

[Defenestrator]

RV antifreeze is usually propylene glycol, which Dow says lasts 2 years unless it's in direct sunlight or gets hot. I'd say sealed it's fine to go several years past that, but if it's been opened I wouldn't use it. It's probably still fine for preventing freezing, but in the presence of oxygen it very slowly degrades to some things that I'd rather not have in my drinking water.

[Donna D.]

I can buy RV antifreeze for $1.99 a gallon. I'm not going to risk $$$$ damage to save a few pennies by recycling/reusing. YMMV

[Brian B-P]

RV plumbing antifreeze can be propylene glycol, alcohol, or a mixture of the two.

I would use it, even opened, and even if I had a free supply. We're not talking about prescription drugs here - it's just antifreeze, and we throw away far too much of everything. Whatever the degration products, they are unlikely to be different from the digestion products, which are not a concern in the quantities which might be encountered in RV plumbing use (assuming you flush the stuff out before using the water in the spring, which of course you'll do).

[Defenestrator]

Yeah, if it's ethanol it's perfectly safe, just a bit less effective if it's been open enough for the ethanol to evaporate.

For propylene glycol, I think it ends up producing some amount of formaldehyde and acetalaldehyde in addition to water. Not sure what percentage though, and it's probably OK as long as you rinse it well before using it again. For $2 though, I'd probably just get a new jug rather than use a questionable one that's more than a couple years old or has been open for a long time.

Either way, for the original question: last year's unopened jug is definitely just fine.

[rbryan4]

I don't have to winterize, so my opinion may be taken with the appropriate grain of salt:

I don't like the whole concept of RV antifreeze. The ethanol variety leaves a foul taste in the lines that takes awhile to dissipate, and the propylene glycol variety can break down into other more problematic compounds. There's also the issue of "some" glycol based RV antifreezes being partially recycled.

To me the best solution would be to blow out the lines. What little RV antifreeze you might have to use would be in the drain p-trap.

[gbaglo]

Propylene glycol is used in the manufacture of ice cream and many other food products. I have a half quart of ice cream in the freezer that I intend to deal with later tonight, with sour cherry pie.

[rbryan4]

Originally Posted by gbaglo

Propylene glycol is used in the manufacture of ice cream and many other food products. I have a half quart of ice cream in the freezer that I intend to deal with later tonight, with sour cherry pie.

Yeah, it's in some Ice Creams to improve the texture and retard the freezing properties, in small amounts. But, I don't like it in my food either.

Sent from my SM-G930V using Tapatalk

[Dave Walter]

Originally Posted by rbryan4

...To me the best solution would be to blow out the lines. What little RV antifreeze you might have to use would be in the drain p-trap.

This method has worked well for me.

[WLYBGR]

Thanks for all the suggestions.So it is probably overkill.But i blew out the lines.Then i used the rv pump to pump thru the lines the old[unused] anti freeze.

[markvt]

Originally Posted by WLYBGR

Thanks for all the suggestions.So it is probably overkill.But i blew out the lines.Then i used the rv pump to pump thru the lines the old[unused] anti freeze.

In my book blowing out the lines and then pumping anti freeze thru the lines is not over kill. It's just a good practice it's better to be safe than sorry.

[David H]

Originally Posted by markvt

In my book blowing out the lines and then pumping anti freeze thru the lines is not over kill. It's just a good practice it's better to be safe than sorry.

I agree "good practice" and do the same, no wasting or diluting the antifreeze. Have a small slug of water trapped in the toilet flush valve and it would be a PITA and 5 times the cost of the jug of antifreeze.