A call out to Beta 50 owners, newer engines in particular.

[GILow]

So, I just pulled the anode.

6 weeks since the last changeover. I just double checked the numbers, turned out the engine had 17.9 hours on it at that first changeover.

Now it has 24.4 hours.

So, 6.5 hours and 6 weeks on the new anode.

The anode is 2/3 gone.

This is not good. Next step will be to try swapping out the stainless pipe to see if that makes a difference.

As an aside, it seems like engine hours makes a small difference, because the previous anode was more than 2/3 gone when I replaced it, but the primary issue seems to be time in the water.

Fingers crossed the pipe replacement fixes the problem.

[malbert73]

Originally Posted by GILow

Please excuse my ignorance, but does this mean you are cruising in fresh water?

We’ve gone blue water but mostly mid/northern Chesapeake so brackish if that would make a difference

[GILow]

Originally Posted by malbert73

We’ve gone blue water but mostly mid/northern Chesapeake so brackish if that would make a difference

Sadly, it makes it difficult to compare. Galvanic activity would be proportional to salt levels, though I am not sure if the response is linear. That one is for someone with better chemistry/physics than me.

[Compass790]

Originally Posted by GILow

Sadly, it makes it difficult to compare. Galvanic activity would be proportional to salt levels, though I am not sure if the response is linear. That one is for someone with better chemistry/physics than me.

Another thing you could do, after changing to hose, is fresh water flush the engine after you return to dock.
We do this with our RW cooled Yammer & its anode lasts years. Sadly I can't tell you what difference it makes to anode life as I fitted a tee for FW hose in RW inlet pipe soon after we bought the boat.
Different metals it's protecting mostly but can't hurt.
Following the saga with interest....

[GILow]

Originally Posted by Compass790

Another thing you could do, after changing to hose, is fresh water flush the engine after you return to dock.
We do this with our RW cooled Yammer & its anode lasts years. Sadly I can't tell you what difference it makes to anode life as I fitted a tee for FW hose in RW inlet pipe soon after we bought the boat.
Different metals it's protecting mostly but can't hurt.
Following the saga with interest....

That would help, though I was supposed to leave the dock in March. Currently locked down by Covid19 but planning to be out in December.

Planning....

Why do I even use that word any more?

[RaymondR]

My understanding is that dissimilar metals in fresh water will generate a voltage similar to that generated in salt water but because the conductivity of salt is higher more current will pass and therefore more wasting occur.

Take a poly plug which will screw into where the anode goes and drill a hole in it slightly smaller than the anode zinc and drive it through the plug. This will break the circuit. Then you can connect your multimeter and using mA setting poke around and find out where the greatest amount of current flows.

[malbert73]

I just wonder if there is something else going on perhaps as I put at least 20-30 hours on engine in full ocean salt water and nearly 100 in southern chesapeake bay where salinity is nearly that of ocean. And mine seems to have same dissimilar metals including stainless pipe and I haven’t yet replaced anode in 2.5 years and 300+ hours

[GILow]

Originally Posted by malbert73

I just wonder if there is something else going on perhaps as I put at least 20-30 hours on engine in full ocean salt water and nearly 100 in southern chesapeake bay where salinity is nearly that of ocean. And mine seems to have same dissimilar metals including stainless pipe and I haven’t yet replaced anode in 2.5 years and 300+ hours

This is the 64 million dollar question.

If I hadn't seen the warning by richardhc in the facebook group I would have assumed the problem is with my boat. (I am still open to that possibility of course, but I've gone over the whole thing with care and it simply is no different to the last engine, as well as being in a very simple fibreglass boat and being totally isolated from the house electrical bank.)

However, it is important to note this issue does seem to affect newer engines, at least those are the ones that Richard mentions and it may simply be that yours has a different construction of heat exchanger or something.

I will implement Richard's solution as soon as I have some spare time (currently I am studying full time with three essays due). At least now I have a reasonable baseline to compare to.

[malbert73]

Also, wonder if it’s because my prop/shaft is not isolated from engine. No shaft saver. Maybe prop shaft anodes are also contributing since in theory bonded to engine block?

[GILow]

Originally Posted by malbert73

Also, wonder if it’s because my prop/shaft is not isolated from engine. No shaft saver. Maybe prop shaft anodes are also contributing since in theory bonded to engine block?

Very interesting point and it certainly means your setup is just too different to make a meaningful comparison, darn it.

But it is one for me to consider if I cannot solve this with the pipe replacement approach advocated by Richard.

As it is, I have a lazy anode on the starboard side I could easily bond to the engine. All it protects is the rudder shaft, and it lasts about four to six years before needing replacement.

My port side anode protects the prop shaft and propellor, and I tend to replace it every two years because I am never sure it will last the next two.

I think perhaps I wouldn't want to add to its load if I could avoid it, which bonding the engine to the drive shaft would do.

[RaymondR]

It's more likely to be something in fairly close proximity like using alloy end caps on the heat exchanger ends.

[GILow]

A follow up to this post:

I eventually got around to swapping the stainless steel pipe for a synthetic hose and swapped the anode.

I have just pulled the anode at exactly two months and it is in excellent condition, probably around 20% depleted. (See photo)

The previous two anodes were 90% gone by two months.

The only difference is that my engine hours were lower this last two months, three hours use vs seven hours in the previous two months, but I just don’t think that would make a big difference.

I have relayed my findings to Beta Australia and they are taking my finding to head office. We discussed any potential downside to this solution and they were adamant that there was no downside, apart from the fact that both agreed the original red stainless steel pipe was very tidy and nice to look at.

And just to be clear, this has been the closest thing to a controlled experiment I could devise on a boat. For the whole time the boat has been in the same pen, no neighbouring boats have come or gone and no significant changes have been made to the boat electrics or bonding system. Aside from the engine hours, the only change was that pipe.

[Compass790]

Bloody dissimilar metals eh!
Good on you for communicating with Beta yr mod. Hope they give you a fistful of anodes & ditch their ss pipe.
Good luck with leaving the dock.

[Jason Flare]

Subscribed to this thread.

I am having a Beta 50 installed as we speak.

[GILow]

Originally Posted by Jason Flare

Subscribed to this thread.

I am having a Beta 50 installed as we speak.

You’ll love it. Very sweet at about 1800 rpm, but pretty good right through the rev range.

I suspect that if the engine is bonded to the boat’s main sacrificial anodes you’ll have no problems, but if, like me, your engine protection system is self contained I bet you will see the same thing. There are a number of others on the Facebook group having the same problem. A few are now trying Richard’s solution.

He really deserves all credit in this for his lateral thinking and sharp observation. I’m just reporting on using his approach.