Date:         Fri, 6 Oct 1995 09:35:08 CST6CDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Dan Houg" <fairwind@northernnet.com>
Subject:      Coolant compositions.

The following info from Prestone Corp.:

TYPICAL NORTH AMERICAN COOLANTS
-phosphate and/or borate
-high silicate
-nitrate
-triazole
-antifoam
-pH 10.0-10.5

TYPICAL EUROPEAN COOLANT
-benzoate
-borate
-silicate
-nitrate
-triazole
-antifoam
-pH 8.0-8.5

PRESTONE Antifreeze
-phosphate
-borate
-silicate (high)
-nitrate
-tolyltriazole

PRESTONE LONG LIFE 4/60
-organic acids
-silicate (low)
-tolytriazole
-nitrate
-molybdate

Here is the formula of a typical antifreeze coolant concentrate that 
is safe for aluminum components:
				Wt. %
ethylene glycol		95.56
sodium nitrate		.10
sodium molybdate		.20
sodium tetraborate	.40
sodium silicate solution	.30
phosphoric acid		.15
MBT (50% solution)		.50
TT (50% solution)		.20
sodium hydroxide		.235
water				2.30
polyalcohol			.05
dye				.005

MBT (mercaptobenzothiazole) is a corrosion inhibitor for copper or 
brass.

TT (tolytriazole) provides protection similar to MBT, but TT is more 
durable at higher temperatures.

Nitrates are corrosion inhibitors for ferrous surfaces, and protect 
from pitting and crevice corrosion.

Silicates inhibit corrosion on hot aluminum surfaces, and provide 
protection from cavitation.  Silicates also act as general purpose 
chemical buffering agents.

Borates provide buffering and neutralizion of acidic and sulfurous 
combustion gas by-products.

Sodium hydroxide helps stabilize pH.

Silicones are antifoam agaents which also slow the silicate reaction 
with magnesium.

Polyalcohol supresses the formation of foam.

Phosphates provide general purpose protection for several metals and 
are effective in preventing the cavitation-erosion damage of 
aluminum.

-dan