Here you go, not sure if this will be a problem in our cars though....
When we buy antifreeze for our cherished old cars we go for the best; well, I did and perhaps mistakenly so. You see them on the shelf and look for the one that says it will give you the best protection. We look to “compliant with BS 6580 suitable for all cars from 1990 onwards, complies with (various) manufacturers safe standards” with the best in-car life of, say, five years. And, not forgetting the price, it’s three pounds or so more expensive than the bottom shelf stuff, so it must be good. And then we tip it in - bad move! Let’s look further; until this year the labeling was not so explicit and that’s when I started looking, thanks to prompting from Uxbridge and District Classic Vehicle Society (U&DCVS) and to the Rolls Royce Enthusiasts’ Club. I had in my cars, Austins from 1926 onwards and the 1966 3. 8 Jag, the so called “best stuff” and it was orange. And that’s the first clue: I had one of the old containers, but scant information was given as to what was inside apart from the usual complies to BS this and that, approved by various associations and a warning not to drink it or pour it down the drains. Going to the various motor part factors I was surprised at the lack of knowledge or information and all but one recommended it for my cars as being the “best stuff”. Only at Halfords where a little girl said “hold on I don’t know, but I will ask my technical department on Monday”. Monday came and just after the lunch break she called back. The answer “Don’t use it, it will strip various alloys out of the lead solder, lead bushes etc, it’s only meant for very modern cars!” Well there you are. So, in older cars where lead, lead solder, lead alloy bushes, graphite/lead water pump lubricated rope are used, expect trouble. One to avoid is “Organic Acid Technology” (OAT); they are normally orange. They are longer lasting, having an in-car life of five years and are cheaper to make. Another one to avoid is the “Hybrid Organic Acid Technology” (HOAT) antifreeze: Daimler/Chrysler’s one is orange and Ford’s is yellow. Also avoid the “Nitrate Organic Acid Technology” for as it says it’s an OAT with Nitrates added. The one to use in our older cars is, and this is supported by Halfords technical department, the older “INORGANIC ADDITIVE TECHNOLOGY” (IAT) ANTIFREEZE, normally blue in colour and often referred to as “conventionally inhibited”. It has only a two year in-car life and is normally ETHYLENE GLYCOL (EG) BASED.
All the above are BS 6580 compliant. Apparently the OAT antifreezes will also attack conventional silicon gasket sealing compounds, Hylomar and its derivatives, the traditional rubber and fabric based water hoses and so on. There is one downside in using EG based antifreezes, they are very toxic. 30ml can be fatal in adults and 4ml will kill a cat! If you want to be safe, green and environmentally friendly you should use a Propylene Glycol The U&DCVS suggest Fernox Alphi II, but I have not come across any of this stuff. Apparently it can be obtained from plumbers merchants.*
A post script; you are advised not to put either the AIT or the OAT antifreezes down the drains, so I called my local domestic refuse tip and asked where I can safely dispose of the old stuff; they had no idea whatsoever of what I was talking about.
