Changing Beta Pencil Anode every six months?

[donm]

Yes, sorry. As you say, the cap furthest from the anode has a nib that needs to align with a groove on the heat exchanger tube - as I learnt from bitter experience!

 

[vyv_cox]

Hi Vyv

Just curious. Why is flushing the seawater side of an indirectly cooled diesel with fresh water and then draining better than flushing the seawater side through with last years fresh water / antifreeze mix. It might be unnecessary if you flush and drain it properly (although I would always worry there was some water left in there) but is there an issue? After all it's quicker and doesn't cost any more?

Sounds like a lot of hassle to me but no particular disadvantage in using the old coolant. What I do is run the engine when ashore, tipping or hosing fresh water into the strainer. If I don't have a hosepipe handy I use two fresh water bottles of 11 litres each, or with a hosepipe run for 5 minutes or so. I then remove the impeller to drain the heat exchanger and if there was a likelihood of freezing I would drain the trap. In Greece this is not necessary.

 

[NormanS]

It's one of those things that some boat owners feel they should do but there is little point in it. In many cases most of the seawater side of an indirectly cooled engine is rubber, along with metals that resist corrosion. In some cases there is an anode in the heat exchanger to protect a galvanic couple that may be there, e.g. tubes of a copper alloy such as aluminium brass (more expensive) or brass (cheap) and a stainless steel jacket. Either way, filling with antifreeze will have no beneficial effect. Flushing with fresh water and draining is the best treatment.

There is a slightly stronger argument with a seawater-cooled engine that is mostly made from cast iron. Filling it with antifreeze solution, or circulating the solution through it when it is hot, adds corrosion inhibitor. However, cast iron is pretty good at resisting corrosion and there are plenty of such engines several decades old that have never seen antifreeze. To my mind the best way of resisting frost damage is total draining, after flushing through with fresh water. A few automotive engine marine conversions may have aluminium parts in them and in this case the corrosion inhibitor would be highly beneficial.

Here in Scotland, and in many other parts of the UK, it can sometimes get quite cold in the winter. The Med, probably less so.

My exhaust, and I expect most others, has water mixing chambers, mufflers etc, which are either impossible, or very difficult to drain. If, after lift out, you run the engine with fresh water to flush out the salt, the fresh water remaining in the exhaust system, is liable to freeze. This could damage these vulnerable parts.

That is why it is common, and sensible practice to put antifreeze into the final flush.

 

[Pye_End]

Have never felt the need to change the raw water for antifreeze in the winter - what is the reasoning behind this?

Upon reflection I have antifreezed the raw water system when there is a particularly cold spell - eg prolonged -4 to -7 sort of temperatures for peace of mind, but this is pretty rare 'down south' (poster report being in Solent and I accept Scotland is a different entity!). However, I tend to keep her in the water over the winter, and up on the side may reach higher temperatures for this 'peace of mind' action.

Particularly the Betas, when changing the anode there is not a lot of water left in the heat exchanger, and for water/ice to damage bits of engine it needs to have nowhere to go. With things like rubber pipes, and air gaps I find it hard to see that expansion is likely to do any damage. Taking the water impeller out takes most of the water out of the pre-h/e part of the pipework, and opening the seacock releases water from the strainer. Our family lives off milk which we keep in the freezer, and it is extremely rare for the plastic bottle to become damaged from the expansion.

When I had a raw water cooled I always wintered with antifreeze - but engine blocks are rather more serious, with less flexibility in the system, and as others have said, salt water sitting in the engine block is best avoided.

I have heard the wet box argument before, but do not know of anyone who has ever suffered from this.

It would be useful to hear from people with experience of winter damage to similar systems to know what sort of conditions actually do cause damage, and to what specific parts to the system - ie is it a 'peace of mind' action, or really necessary.

 

[vyv_cox]

Here in Scotland, and in many other parts of the UK, it can sometimes get quite cold in the winter. The Med, probably less so.

My exhaust, and I expect most others, has water mixing chambers, mufflers etc, which are either impossible, or very difficult to drain. If, after lift out, you run the engine with fresh water to flush out the salt, the fresh water remaining in the exhaust system, is liable to freeze. This could damage these vulnerable parts.

That is why it is common, and sensible practice to put antifreeze into the final flush.

I have owned several boats and even more exhaust traps. Every one had a drain tap. That's why I wrote 'and draining'. If your exhaust system cannot be drained then antifreeze might well be advisable, although personally I would prefer to add a drain.

 

[345000]

Hi All,

Just something else to throw into the mix - Antifreeze should be changed at least every two or three years (just as in a car), as not only does it provide frost protection, it also has corrosion inhibitors, which are depleted with time.

Best Regards,

Dave.

 

[BabaYaga]

With the first time of winterizing my Beta 25 engine I thought I should explore the engine a bit and change the pencil anode. As part of winterizing you suck up antifreeze mix through the sea water part of the cooling system and I did this. Then I have changed the pencil anode which was well wasted. But obviously the anode is not going into a seawater situation until I launch the boat next season. So does the six month rule apply from now or when back in the water?

Just want to encourage the use of antifreeze if there is any risk of frost. In my view it would be difficult to be certain that the tube stack was completely drained, especially on a newer engine. (The anode used to sit in a low spot on the rear end cap, but from 2011 or so the design changed if I an not mistaken. The anode now sits in the upper half of the end cap, in the water stream leaving the heat exchanger).
BTW if it is difficult to catch the glycol when the engine is started again, try and get hold of propylene glycol, less harmful to the environment than ethylene glycol.
I do not think you have to worry about the anode wasting during the period when the engine is not run. Part of the anode wasting IMO has to do cooling water running, that is mechanical wear.

 

[RichardS]

Hi All,

Just something else to throw into the mix - Antifreeze should be changed at least every two or three years (just as in a car), as not only does it provide frost protection, it also has corrosion inhibitors, which are depleted with time.

Best Regards,

Dave.

Many cars these days come with long life coolant using OAT technology. The normal change period is 5 years but some car manufacturers are now referring to this as lifelong / 100,000 miles.

OAT can also be used in marine diesels.

Richard

 

[Pye_End]

Many cars these days come with long life coolant using OAT technology. The normal change period is 5 years but some car manufacturers are now referring to this as lifelong / 100,000 miles.

OAT can also be used in marine diesels.

Richard

After a long thread about this some time ago I contacted the makers of antifreeze (Granville I think) and they agreed with the consensus of the thread - ie OAT technology is not suitable for marine diesels.

 

[RichardS]

After a long thread about this some time ago I contacted the makers of antifreeze (Granville I think) and they agreed with the consensus of the thread - ie OAT technology is not suitable for marine diesels.

The Texaco / Havoline antifeeze recommended by Yanmar for my 3YM30 is OAT although Texaco have their own name for this technology. The recommended change interval for cars is a mimimum of 150,000 miles for petrol engines and up to 400,000 miles for diesel engines. There is no other technology which will last this long.

Of course, what I do is not necessarily what others might wish to do.

Richard

 

[Pye_End]

The Texaco / Havoline antifeeze recommended by Yanmar for my 3YM30 is OAT although Texaco have their own name for this technology. The recommended change interval for cars is a mimimum of 150,000 miles for petrol engines and up to 400,000 miles for diesel engines. There is no other technology which will last this long.

Interesting.

The odd post on this forum suggests OAT is not compatible with copper heat exchangers - what is the Yanmar made from?

I should be more precise over the message from Granville - they looked up my engine on their database and the recommended antifreeze is blue, as were a load of other Betas. Beta themselves did not give me an answer. When it had OAT in mine there was a muddy/grainy residue, which may have been responsible for blocking the drain. Since changing to blue it has been clean.

 

[VicS]

After a long thread about this some time ago I contacted the makers of antifreeze (Granville I think) and they agreed with the consensus of the thread - ie OAT technology is not suitable for marine diesels.

The Texaco / Havoline antifeeze recommended by Yanmar for my 3YM30 is OAT although Texaco have their own name for this technology. The recommended change interval for cars is a mimimum of 150,000 miles for petrol engines and up to 400,000 miles for diesel engines. There is no other technology which will last this long.

Of course, what I do is not necessarily what others might wish to do.

Richard

Interesting.

The odd post on this forum suggests OAT is not compatible with copper heat exchangers - what is the Yanmar made from?

I should be more precise over the message from Granville - they looked up my engine on their database and the recommended antifreeze is blue, as were a load of other Betas. Beta themselves did not give me an answer. When it had OAT in mine there was a muddy/grainy residue, which may have been responsible for blocking the drain. Since changing to blue it has been clean.

I believe OAT antifreeze is specified, not just recommended, by Yanmar to avoid cavitation erosion of cylinder liners. It may not apply to all but I am sure it does to some.

The problem with OAT and copper radiators may be the solder used in their construction rather rather than the copper itself.

The inhibitors in long life / OAT are not compatible with the conventional/low silicate type. It is said that one will precipitate the other ( although nothing happens in a test tube in the cold) but having managed to mix the two in my car it might explain why the heater matrix is now blocked.

 

[charles_reed]

After a long thread about this some time ago I contacted the makers of antifreeze (Granville I think) and they agreed with the consensus of the thread - ie OAT technology is not suitable for marine diesels.

I think you've missed the point - conventional car antifreeze has a recommended lifetime change of between 5-7 years, not the 2-3 you suggest. With polypropylene glycol the oxidisation to lactic acid make it highly desirable it's changed regularly. Ethylene glycol, on the other hand is far safer (if you don't drink it), in your average cooling systems.
Your information about OAT antifreeze applies to one supplier alone, and probably refers to the ongoing GM litigation caused by build-up of 2-ethyl-hexanoic acid causing the seizing of radiator caps over a period of poor topping-up by car owners.
For that reason Honda and Toyota use no 2-EHA in their lifetime antifreeze - it's probable that this has no contra-indication for marine use.
A more cogent reason, especially with marine cooling systems, is the build-up of biological contaminants which is probably worse in OAT & polypropylene than the breakdown of inhibitors - for that reason alone I would agree that ethylene glycol is probably the "best" inhibitor in marine systems.

PS Though your first recommendation suggests you might have worked for a manufacturer of anti-freeze, your subsequent contentions suggest the change-period recommendation was down to excess enthusiasm ;-)

PSS Yanmar now actually recommend OAT with no 2-EHA, justifiably, not trusting their end-users to change ethylene-glycol regularly. Sludge in a coolant system is usually down to a bacterial infection, to which OAT is particularly susceptible unless your engine has a sealed cooling system (ie an overflow tank with the pipe below the cold coolant level). As it is desirable to change indirect coolant regularly, I will continue to use (green mainly) ethylene glycol, changing it every 5th year - there is no replacement, though, for reading the ingredients on the can, as there are a rainbow of colours out there with each manufacturer making various (usually spurious) claims for their mixture.