Coolant

[Steve kay]

   
Taking the water manifold off, I discovered the stuff/substances/mush illustrated. It was certainly not hard scale, indeed after an hour or so of drying  it brushed away, almost like fluff. I have an old fashioned fear of galvanic corrosion, and rads getting gooed up, so the  Ruby always uses Fernox, the container is Fernox F1. Here in South Wales the quality of water is not bad, so any thoughts on what is in the coolant, whether that is the correct Fernox,  and what precautions should be taken as the mighty engine is bolted back together?

[Robert Leigh]

The information on the web suggests that Fernox F1 should be right for iron and aluminium. Possibly your water in that area is soft with a relatively low pH. I suggest that distilled water is best. Water from a dehuidifier is effectively just that, or you can use water from defrosting the fridge or freezer. If the deposit is soft as you say, power flushing with a hose alternately in each engine connection on an annual basis will probably clear the system usefully. I have to admit that I do not worry unduly about my cooling systems unles there are signs of a problem.

[Eddamoo]

Is there any reason why you wouldn't just use normal modern car coolant? Its designed to work with both Alu/Iron and has the relevant corrosion inhibitors. It is probably also better suited to the higher running temperatures of an engine vs a domestic heating system (90-100C vs 60-70C)

[circeonya@hotmail.com]

What is against soluble oil ? Most corrosion inhibitors raise the boiling point but beccome corrosive after a certain time. And in some parts of the UK an anti freeze is needed.

[Russlin]

I have found soluble oil to attack coolant hoses.

[Bob Culver]

There is an Australasian standard Type B which has no anti freeze property and is relatively cheap. I have used for decades in ny Hillman and the iron is as new. Slight corrosion of alloy occurs.  Gather it has Specific Heat  near 1, much better than anti freeze., and rumoured  used in competition cars.

[Chris KC]

I guess that's what the Penrite product is Bob. A little dearer than CH additive but (one presumes) formulated for automotive use.
I was using it in my Ulster rep but it seemed to be reacting with the enamel paint on my rad surround and bonnet front, so I have 'paused' it.