Hi Wayne,
I remember this post that’s why I have the Thermocure by Evapo-Rust up in this post. 
I don’t need to do anything with the cooling system at present but I will, no doubt, at some stage. I was just asking the members of the Forum so that I had the information to hand and wouldn’t follow the mistakes others might have made, as well gain any insights such as yours! 
Thanks again!
Cheers,
Tim
Hi,
Again looks like I’ve been doing the flushing wrong (garden hose, as I have nothing better at the cottage garage) but why 50/50?
Why not 33/67?
Only downside should be that it would not stand colder than -20C, right?
I have alway believed thats cooling fluid that has a bit more water than glycol transfers heat better, both from the head to the fluid and from the fluid to the copper core in the radiator.
And IMHO also RedLine Waterwetter improved the situation with a couple of degrees (which is good if you are getting near 100C degrees.
Cheers!
That question surprised me. I thought Helsinki got colder than Chicago. Anyway around here it is 50/50.
I got curious about Evapo-Rust and found the Safety Data Sheet. The special chemical in it is a trade secret, less than 16%, the remainder being water. It is mostly non-hazardous to humans unless you drink it, but don’t pour it down the storm sewers.
Hi,
This is the one I’ve been using as it meets these specs:
BS 6580-2010 and AFNOR NFR 15-601
They say:
2:1 = -18°C
1:1 = -36°C
3:2 = -52°C (now THAT’S COLD! ) 
So I’ve been using 2:1 in all my classic cars, as I rarely drive or leave them outside, if it’s colder than -18°C!!! 
(that’s minus 0.4°F)
Cheers!
Ps. Looks like with your product 40/60 is safe up to -18°C. They don’t explain about the hear transfer properties, but I have been under the assumption that with all glycol based cooling fluids, the more water the mix has, the better it will transfer heat via the radiator. Don’t pour in rainwater or normal sewers, we take this always to gas stations or hazardous waste disposal, they take it for free and it goes where it should. In an open container or in the nature it’s very harmful as it smells sugar and all kinds of animals could drink it and destroy their kidneys for good. 
The record low in Chicago’s western burbs is -28F or -33C.
I drove the '74 XJ12 to work that day. Brrrr
Same caution here with old anti-freeze, don’t leave it out because animals drink it.
It even tastes sweet if you want to check what’s in your header tank! (You don’t need more than a drop on the end of your finger.)
Peter 
