I will be starting this 1931 chev coupe soon.
The radiator has been re-done and tested, but has not been filled in a few years.
What coolent to water mix should I start with?
Thanks Stanman

I always run 50/50 antifreeze and water. If you just want to check for leaks, plain water would be fine as long as it is above freezing which I would think it is in Ca. After you are sure there are no leaks, I would run at least some antifreeze as it has some desirable additives such as anti rust but in Ca. you might not have to run 50/50, maybe 30/70.

I always test fill and initial warm up with straight water then completely drain and fill with anti freeze/ anti corrosive when I am sure there is no leaks.
Tony

Just go with 5050. Don't mix your own. By mixing your own, you won't know what you've actually ended up with over time. Savings realized by mixing your own are not worth the extra effort and, sometimes, at least, better water.

As to leaks, just have a pail handy and slip it underneath the leak. Merely strain it after the leak is taken care of.

Note: Those in Tennessee and around Cincinnati may opt for the more handy lard stand or wash tub. Just make sure the bath water is out of the tub. Grin.
Charlie

Do it the way that is best for you, however I mix my own, since I have 3 trucks, three cars, a tractor and a Kawasaki liquid cooled Mule, I realize quite a bit of savings each year

I have found that “bargain brands” of anti-freeze coolant already mixed 50-50 doesn’t always check out as they should, kind of light on the anti-freeze part. Charlie probably doesn’t have to worry as to whether the mixture is 35 degrees below zero or 10 degrees above zero, but some of us do. Granted pre-mixed or full strength anti-freeze will deteriorate after several years of being stored. It isn’t hard to mix and you can be sure you are getting a correct 50-50 mix. Buy 2 gallons of antifreeze and 2 gallons of distilled water I never put tap water into a radiator or a battery. Distilled water sells for less than $1/gallon, pour them into a clean 5 gallon bucket, (one gallon of each at a time), mix and pour into the radiator using a funnel repeat, and what you have left if any, pour into one of the antifreeze containers and use a black Sharpie marker to label the container the date that it was mixed, stick it in the trunk for use on the road. While you are buying the distilled water get a couple of extra gallons to use as battery water.

All good information and suggestions.

If you mix your own as stated then you will always have premix on hand and the coolant in the radiator will always be 50/50. draining and refilling with non diluted can cause variations in the degree of protection.My water faucet provides cheaper water than the stuff i premix as there is no freight and additional profit added.

I would recommend distilled water as previous post unless you have tested you water supply and it is comparable.