In Reply to: Re: 2N coolant posted by Dead Eye Dave on October 28, 2020 at 03:06:25:
Antifreeze manufacturers have formulated their products for long life and the inhibitor attacks among other things silicone compound – the most commonly used base for gasket sealants. It also attacks lead-based products (solder and Babbit), some yellow metals (cam bearings, radiators) and conventional gaskets and packing materials. Do NOT use coolants with OAT inhibitors in your Model A. Read the label and use only IAT (Inorganic Additive Technology) inhibited antifreeze. OAT stands for “Organic Acid Technology” based corrosion inhibitors and they are designed to have longer service life than that of IAT coolants. Unfortunately, that feature comes with a bad side effect to older cars. One fellow decided to change antifreeze in his antique car. His regular brand was out of stock so he bought the “advanced” formula. Four weeks later he found pools of antifreeze under his car. The antifreeze had dissolved the old gaskets. It was formulated with OAT inhibitors.
Here are some tips for finding IAT coolants:
Prestone says that all of their current antifreezes are OAT formulas.
Peak says that their antifreeze and coolant is an IAT formula. The container is blue. It is important that it not say “long life”.
Peak Sierra brand is propylene glycol for those who prefer that. It too uses an IAT formula.
Zerex says that Zerex Original Green is an IAT formula. It comes in a white container. Do not use their G-05 formula in the gold jug.