anti freeze/inhibitor for skin tank

[Mike Adams]

My recently installed skin tank and engine have a capacity of 30 litres. I am loathe to put conventional antifreeze in the system in case I have to drain it down or get a leak and need to get rid of 30 litres of used coolant full of ethyl glycol. Screwfix do a central heating inhibitor and antifreeze that it says is safe to dispose of down a sewer. I was wondering if this would be OK instead of the conventional car stuff and it works out about the same price. Flowmasta corrosion inhibited antifreeze it is called and I don't suppose it would have any effect on the heat transfer.

[BEngo]

I can see no reason why you can not use it.  The flow temperatures are similar to those in a modern CH set up.  

Glycol does have some advantages in heat transfer performance, and in boiling point at altitude.  Neither of these are likely to be key to your use of coolant, even if you intend to frequent Standedge?.

I would want to make sure it is OK for alloy components, if you have any in coolant contact, and I would want to make sure that it has acceptable antifreeze temperature performance. The temperature at which it goes slushy is the important one, as at that point the engine is, practically, unusable as the coolant will no longer circulate and the car trick of getting the engine hot then switching off till the hot block defrosts the radieator usually doesn't work in an engine bay.

 

N

 

 

[WotEver]

The product details state that it’s fine on all alloys, non-toxic, highly organic and at 25% concentration protects down to -11C. 

 

They also state no problem with using a higher concentration. 

[David Mack]

NMEA recommended it for central heating systems a year ago.

 

 

[WotEver]

9 minutes ago, David Mack said:

NMEA recommended it for central heating systems a year ago  

Yes he did, but not for engine cooling. 

 

 

Edited March 14, 2019 by WotEver
Typo

[Mike Adams]

Interesting point about altitude. As the system is pressurised to 15psi (I think) would it make any difference in Standedge? I was thinking about that one but I assume the cap works on absolute rather than differential pressure.

 

[David Mack]

1 hour ago, WotEver said:

Yes he did, but not for engine cooling. 

 

 

But it's doing the same job, a probably at similar temperatures.

[Sea Dog]

1 minute ago, David Mack said:

But it's doing the same job, a probably at similar temperatures.

There's a lot of different components exposed to coolant in an engine than a central heating system though.  I have Flomasta Inhibited antifreeze in my Eberspacher central heating, principally because I know exactly what compatible inhibitor I can add periodically rather than keep replacing the lot, but I go with the engine manufacturer's recommendations for the engine.  I'd be interested to hear if anyone has experience of using central heating stuff in their engine, particularly as the easy disposal is very attractive, but I'm not sure I'd join in without convincing evidence that it is good for the engine.

[WotEver]

29 minutes ago, Sea Dog said:

There's a lot of different components exposed to coolant in an engine than a central heating system though.

As well as higher temperatures. 

[Boater Sam]

The red polyethylene antifreeze is non toxic I think. And lasts longer than blue ethylene glycol

[WotEver]

9 hours ago, Boater Sam said:

The red polyethylene antifreeze is non toxic I think. And lasts longer than blue ethylene glycol

Polyethylene Glycol is a commonly available laxative... so yes, non toxic at low concentrations. 

[Jen-in-Wellies]

Propylene Glycol is the name of the antifreeze component. I've used it in the boats back boiler heating circuit and in the solar thermal hot water system. Very safe compared with the toxic Ethylene Glycol. Even used as a food additive. You can buy a version for cars, which might be more suitable for a boat engine.

 

Jen

[WotEver]

1 hour ago, Jen-in-Wellies said:

Propylene Glycol is the name of the antifreeze component...

... and is the liquid used in E-Ciggys