If in doubt just use Jack Daniels

they make a new anti freeze that dogs can drink and not die...i think its called sierra, my dog loves it

The antifreeze cannot be used in radiators because it is not a coolant. It will also slush up in the winter and not flow properly. On the bottle it gives the burst protection level. That doesn't mean it won't get slushy or hard, just that it won't expand and break anything. You can't use regular automotive antifreeze legally unless you recover all of it. I have winterized thousands of engines in New York with it over many years with no failures.

Hi,
Just brought 5 Jugs of Super Tech RV & Marine Antifreeze to winterize my hot tub. Put 4 jugs in the system and left the last one sitting on top of the tub. Got down to -12°F last night. The jug on top of the tub was froozen solid and showed distortion to the container from expansion. I was searching the internet to see if anyone else had similiar occurances. Don't know if it is a bad batch or what but am in the process of heathing up the hot tub enouch so I can get the frozen antifreeze out of it and try something else. Before I was using regualr automotive antifreeze but it took quite a few rinses (a lot of water) to get rid of the antifreeze smell.
Any pointers will be greatly appreciated. I had used this stuff several years ago in my camper and don't ever remember it freezing up like this.
Thanks,

So your antifreeze froze solid? How much water was in the tub when you added the antifreeze? Hopefully not much more than 4 gals.

We drain our tub during the summer and only use it in the winter.

aren't there rust inhibitors in real anti freeze vs. the rv stuff? I'm not using rv...not for me.

Why is everyone afraid to drain the block & manifolds before adding antifreeze ? This practice of running the engine until the thermostat opens and then adding antifreeze is silly. Adding antifreeze to an already full motor, hoping it will mix is not safe. Always drain block and manifolds. Even if you can only get to one side, the antifreeze can then mix and dilute the remaining water.

Ethylene Glycol aka brands like Prestone etc. have rust inhibitors...protect rubber components much better...it is toxic and needs to be collected and not run down a drain...but yea...much better than just methylene/water and color tinting.

Thuough I hear the blue stuff has corrosion inhibitors but not the "red pop"...

...I am a bit out of my niche' but that's the scoop....

Have you tried squeezing between 2 motors to reach the drains and disconnect hoses? Drained them the 1st 2 yrs I owned the boat. A couple hr job. This past winter I did the running method. 5 min to warm up, 1 min to suck the antifreeze in.

Have I tried, yes I have. In fact it's my business. I have winterized many boats like yours and I have replaced many engines as a result of customers using your method. Next time try pulling the circulating hose off of the water pump. That will drain the motor approximately half way down leaving room for antifreeze to mix with the remaining water. Exhaust manifolds can be easily drained by removing supply hose at thermostat housing and then pulling it down below manifold level. May take a little more time, but well worth the effort!