RV antifreeze

mona

How long is a half used jug of antifreeze good for? I have some left from last year. Not sure if I should use it or disgard it.

Jeannie

Dalehelman

I don't believe it has a shelf life. If it did it would certainly be more than a year. 

BrianZ

2 years according to one source I read.

ScottG

I think most RV antifreezes are ethanol based, so the biggest concern might be the volatile ethanol evaporating and making the solution less effective.

Believe it or not, I've experienced something very similar with a very old, very nearly empty bottle of Irish whiskey!

ericnliz

Sooooo.....Did it make 'ya more volatile @ScottG?????

ScottG

ericnliz said:

Sooooo.....Did it make 'ya more volatile @ScottG?????

Unfortunately, no. That was the problem!  ;-)

BrianZ

I think most RV antifreeze (pink) uses propylene glycol, which is considered nontoxic to humans (but toxic to cats); as opposed to automotive antifreeze (blue) which uses ethylene glycol and is very toxic.

Incidentally, I had read complaints about RV antifreeze not living up to its rating ("protects down to -75°F", etc), because it was not staying liquid, but forming ice when placed in a freezer.  So I put some in an empty plastic coke bottle to test.  Surprisingly to me, it did not stay liquid, but formed some ice, like a slushy mix of ice & liquid.  Apparently, this is normal, and it will still protect plumbing pipes, because it doesn't form a solid block of ice, but easily collapses under pressure.

Warning:  If you want to try this yourself, I suggest labeling the bottle "Antifreeze: propylene glycol.  Do not drink!".  That way, you can avoid scaring your sister-in-law half to death when she finds it & decides to taste it & you tell her that what she just tasted was not pink lemonade, but antifreeze! 
Fortunately, I was able to reassure her that it was non-toxic & she was a good sport, so we still had a Happy Thanksgiving.

ScottG

Some RV antifreezes may be propylene glycol, but I believe that others--particularly the cheaper ones you find everywhere--are alcohol based. The fine print on the bottle should tell you which type you have.

BrianZ

Yes, definitely need to read the fine print.  In my limited experience shopping for RV antifreeze locally & online I found the majority listing ingredients were propylene glycol based.  I only found one source so far listing ethanol, though some didn't list ingredients online.
 
I did find two or three RV articles reporting that ethanol based antifreeze is either not preferred or not recommended, citing flammability, bad aftertaste in plumbing, and potential damage to rubber in valves.  The propylene glycol one I got from Walmart was like 3 or $4 for a gallon jug, which seems cheap to me & I only used half.  I wonder if articles like these could be changing the supply & demand.

Ratkity

RV antifreeze at this time of year usually rises to around $12/gallon. You can get it online cheaper and in the off-season. The average is about $7 a gallon, but I saw a $4 one on Amazon just now. 

It's not just ethanol in it, it's the poisonous non-environmentally friendly 'ethylene glycol' formulation that doesn't belong in an RV line. 

BrianZ

How To Remember Which Antifreeze to Use:

Ethylene Glycol:    E = for Engines   (blue)

Propylene Glycol:  P = for Pipes (also = Pink)