How often, it at all, do you change your anti-freeze?

[Wanderer Vagabond]

Since we are moving into that time of year when things can possibly freeze, how often do people change their antifreeze? I've been on the boat for about five and a half years now and have occasionally topped up the system and back in 2016, due to an error on my part (I over-tightened the alternator drive belt and trashed the water pump bearing) I had to drain half of the system to replace the water pump, got rid of a load of crud and refilled it with some new antifreeze and some of the old that had been filtered. This wasn't a cost saving exercise but I didn't have anywhere to dispose of the old antifreeze.

 

Thinking back to the days of when I had a car, the last one I had lasted me for about 18 years but I never bothered to change the antifreeze; I know the rust inhibitors may deteriorate but the fluid in the system still looks pretty clean. Given the difficulty in disposing of the old antifreeze (tipping it in the cut or down a sanitary station isn't really the way to go and I don't want to tip it in a hedge or anywhere similar since antifreeze is sweet tasting and dogs have been know to lick it up, it is also highly toxic!) I'm reluctant to bother if it isn't generally considered necessary but what do others do?

[dor]

The anti-freezing bit shouldn't deteriorate if it is topped up with a similar strength.  The anti-corrosion properties will go down, but it's cheaper to add some Fernox every couple of years rather than draining the whole system (and having to dispose of the used glycol which is very poisonous).

 

In the good old days you used to see engines with a label on saying "Do Not Drain" because they had antifreeze added.

 

ETA: I'm not convinced the heavy lumps of cast iron we call engines really suffer that much from corrosion, but the central heating system will.

Edited November 26, 2018 by dor

[Wanderer Vagabond]

26 minutes ago, dor said:

The anti-freezing bit shouldn't deteriorate if it is topped up with a similar strength.  The anti-corrosion properties will go down, but it's cheaper to add some Fernox every couple of years rather than draining the whole system (and having to dispose of the used glycol which is very poisonous).

 

In the good old days you used to see engines with a label on saying "Do Not Drain" because they had antifreeze added.

 

ETA: I'm not convinced the heavy lumps of cast iron we call engines really suffer that much from corrosion, but the central heating system will.

I've got a top up bottle of about 50% strength so I would think that the concentration in the system is probably OK. The antifreeze that the previous owner put in the system (or at least the top up bottle he left) was an OAT antifreeze so I've just continued with the same stuff. I'm not sure about putting Fernox in the system, mainly because I don't know a lot about it and when you buy the antifreeze from Halfords (yeah, I know, but they are convenient!) they get quite excited about not mixing different types of antifreeze for some reason or another.

 

ETA I know what you mean about the central heating system, but then the domestic heating system in my house hasn't got any antifreeze in it and seems to have survived the last 30 years OK, or am I tempting fate?

Edited November 26, 2018 by Wanderer Vagabond

[Guest]

We had our boat five winters in total and in that time changed the anti freeze twice.

 

As far as I understand it, it's the corrosion inhibitors that deteriorate and not the anti freezing properties.

 

When I say 'change' I mean I got as much out as I could and then topped up with 50/50

34 minutes ago, Wanderer Vagabond said:

 

ETA I know what you mean about the central heating system, but then the domestic heating system in my house hasn't got any antifreeze in it and seems to have survived the last 30 years OK, or am I tempting fate?

Possibly yes, you really should have some sort of corrosion inhibitor in it. It's unlikely to actually freeze though.

[TheBiscuits]

https://www.morrislubricants.co.uk/products/ind/corrosion-protection/ankorsol-anti-corrosion-fluid-clear.html

 

Add this (mixed with your current coolant) back into your system - ie drain down, mix and refill - don't just tip it in.

Edited November 27, 2018 by TheBiscuits

[WotEver]

10 hours ago, Wanderer Vagabond said:

ETA I know what you mean about the central heating system, but then the domestic heating system in my house hasn't got any antifreeze in it and seems to have survived the last 30 years OK, or am I tempting fate?

Without corrosion inhibitor you will have internal corrosion of steel radiators etc. It’ll only be slow but it will be happening. 

[peterboat]

OATs is 5 years if orange/pink and ten years if violet, its also said to be less poisoness than the older stuff. I like others add fernox anti corrosion inhibitor at the 5 year point with no mixing issues [I have OATs in my system]

[Jen-in-Wellies]

I've changed the coolant at five year intervals, with the pink five year stuff. It is a messy job, at least the way I've done it by taking off the bottom hose from the skin tank and trying to direct the stuff in to a bowl. Just adding fresh corrosion inhibitor to replace it as it ages does sound enticing.

 

Jen, who can't do things like this without making a mess.

[Machpoint005]

I use a top-up inhibitor, but since I never seem to lose any coolant I always have to take some out before the new inhibitor will fit! 

 

(Beta 43 engine)

[Sea Dog]

In my engine I use 5 year automotive antifreeze and change it at the specified interval rather than take a chance on mixing fresh inhibitor that I can't be certain is compatible.  I'm happy to put up with a little faff and moderate expense every 5 years to ensure the protection of my very expensive engine.

 

However, I use domestic central heating antifreeze with inhibitor in my boat's central heating, so I know that I can add inhibitor from the same manufacturer from time to time and be assured of compatibility. 

 

Wanderer Vagabond: whilst few domestic properties have antifreeze in their heating systems, the risks and the ways they might be mitigated are not the same risk as in boats which might get very cold for periods over the winter. Whilst boat pipework beneath the waterline is less likely to freeze because of the water temperature, the liquid higher up (in radiators, header tank and in the Eberspacher or whatever), is at much greater risk.  Even if you live aboard and have the boat interior warm most of the time, an unattended boat can lose temperature very rapidly.  So, if you're canvassing for opinions, I'd say you'd be tempting fate!

 

 

[Wanderer Vagabond]

16 minutes ago, Sea Dog said:

In my engine I use 5 year automotive antifreeze and change it at the specified interval rather than take a chance on mixing fresh inhibitor that I can't be certain is compatible.  I'm happy to put up with a little faff and moderate expense every 5 years to ensure the protection of my very expensive engine.

 

However, I use domestic central heating antifreeze with inhibitor in my boat's central heating, so I know that I can add inhibitor from the same manufacturer from time to time and be assured of compatibility. 

 

Wanderer Vagabond: whilst few domestic properties have antifreeze in their heating systems, the risks and the ways they might be mitigated are not the same risk as in boats which might get very cold for periods over the winter. Whilst boat pipework beneath the waterline is less likely to freeze because of the water temperature, the liquid higher up (in radiators, header tank and in the Eberspacher or whatever), is at much greater risk.  Even if you live aboard and have the boat interior warm most of the time, an unattended boat can lose temperature very rapidly.  So, if you're canvassing for opinions, I'd say you'd be tempting fate!

 

 

When I asked if I was tempting fate, it was with regard to the 30+ year old domestic heating system, not the one on the boat, the one on the boat has got antifreeze in it. Given that I've found it cheaper to heat a (relatively) small boat compared to a larger house during the winter, the house has been unoccupied for long periods in cold weather in the past (with the water turned off) so I suppose that there was a risk that it could have frozen.

 

2 hours ago, peterboat said:

OATs is 5 years if orange/pink and ten years if violet, its also said to be less poisoness than the older stuff. I like others add fernox anti corrosion inhibitor at the 5 year point with no mixing issues [I have OATs in my system]

Thanks for that, I didn't want to put Fernox into the system with no idea over compatibility. I think topping up with a corrosion inhibitor is the approach I shall make since, if changing the whole fluid, there still hasn't been much of a suggestion with what to do with the old antifreeze. I suppose I could put into a boatyard and get them to do it thus giving them the problem of disposal, but at the usual rate of £45 per hour it could be an expensive option for a relatively simple job.

[Boater Sam]

I changed mine in the engine this year, first time in 18 years.

Vacced out the skin tank, very little sludge or rust evident. It was red non toxic so no problem with disposal.

It will be a long while before it gets done again, it took 24 litres of concentrated polyprop antifreeze with lots of water to give a 25% concentration.

[rgreg]

I know someone who changed his engine coolant after owning his boat from new for 10 years, only to find it had never had anti-freeze in it! He isn't a liveaboard either so it wasn't in regular use over winter. If any damage was done it hasn't been apparent yet. 

[Naughty Cal]

We change ours at 5 year periods with the Green VP antifreeze. 

 

There is probably nothing wrong with it when we change it but we would rather be safe then sorry with the cost of a new engine and coolers 

[Sea Dog]

52 minutes ago, Wanderer Vagabond said:

When I asked if I was tempting fate, it was with regard to the 30+ year old domestic heating system, not the one on the boat, the one on the boat has got antifreeze in it. 

Ah, I see!  Modern, retrofittable, controls allow you to choose a program which for example will leave the heating off but with a "frost protect" floor of 7 degrees. These can either be relatively simple programmable thermostats or "smart" versions.  Ours (Hive, others are available) does this and also allows me to fully control the system remotely by phone app.  Perhaps something like this might suit your circumstances? 

[WotEver]

1 hour ago, Sea Dog said:

Ours (Hive, others are available) 

I can attest to the simplicity of fitting a Hive controller. It took me all of 10 minutes including setting up the WiFi connection. 

[TheBiscuits]

1 hour ago, Sea Dog said:

Ah, I see!  Modern, retrofittable, controls allow you to choose a program which for example will leave the heating off but with a "frost protect" floor of 7 degrees. These can either be relatively simple programmable thermostats or "smart" versions.   

Alternatively a "dumb" manual thermostat set to 7 degrees with the heating set to "Always on" will have exactly the same effect.

[Machpoint005]

Depends where the thermostat is measuring the temperature, but in principle, yes, I agree with you, especially where avoiding putting stuff on smartphones is concerned.  I wouldn't be without my scientific calculator, pitch pipe and metronome apps though.

[MtB]

 

Which type of antifreeze does The Team think I have in mine?

 

It is the colour of rusty mud. 

 

 

[Machpoint005]

Just now, Mike the Boilerman said:

 

Which type of antifreeze does The Team think I have in mine?

 

It is the colour of rusty mud. 

 

 

If it were the colour of muddy rust I'd have been able to suggest what it was ...

[MtB]

1 minute ago, Machpoint005 said:

If it were the colour of muddy rust I'd have been able to suggest what it was ...

 

Last year it was a cheerful bright pink!

 

 

[Machpoint005]

There's your answer, Mike!

[MtB]

5 minutes ago, Machpoint005 said:

There's your answer, Mike!

 

Expired antifreeze?

 

I ask because I had a goggle the other day and the one thing I learned is the colour can NOT be relied on to identify the type of antifreeze. All the sites seemed to be american though. Is the colour a reliable guide here in the UK?

 

Point being, how does one dispose of antifreeze? Can the pink stuff just be poured down the elsan? 

Edited November 27, 2018 by Mike the Boilerman

[Mac of Cygnet]

6 hours ago, peterboat said:

OATs is 5 years if orange/pink and ten years if violet, its also said to be less poisoness than the older stuff. I like others add fernox anti corrosion inhibitor at the 5 year point with no mixing issues [I have OATs in my system]

 

I believe this is (potentially dangerously) untrue, in this country at least. Ethylene glycol antifreeze can be any colour. The less poisonous propylene glycol stuff is usually red, but the colour is not a guide (unlike in the US, I think, where red is reserved for PG based antifreeze).  PG antifreeze will be clearly labelled as such. There seems to be a complete lack of standardisation in antifreeze colours.

[Bee]

My Beta 43 has a little drain tap on the block. I turned it on to drain the coolant  and nothing came out, prodded a wire coat hanger up it and a whole load of rusty antifreeze /water stuff came out. It was probably 5, maybe 6 years old. Since then it gets changed every 2 or 3 years.