Mussels in cooling system

[stonecrop]

3 Weeks after my boat was put back in the water having been stored for 6 months, the engine overheated due to the cooling intake hose and cooling pump being completely blocked by mussels. These must have grown in the cooling system within 3 weeks. The mussels passed through the external intake filter and grown rapidly in the cooling intake pipe. Does anyone have any suggestions for preventing this problem reoccurring? Fitting a clear pipe would work for a while but would soon become cloudy and obscured.

 

[tcm]

I don't think mussels grow that quickly!

You can clear intake growth by closing the pimary intake valve, removing the hose, running the bilge pumps and then openingthe valve (the boat is now sinking...) and wopping away attem with a bit of broom handle, then close the valve, phew.

Another option I have just thought of but not used upstream of the valve is to use some hydrochloric acid (cheap and easy to buy in france) fill the filter chamber and turn (but don't start) the engine which will hit everything up to the impellor (but not the impellor if you turn it just a touch). Wait 10 minutes and then use a roving bilge pipe to suck out the cack. Abuse welcome regarding the wisdom of this idea.

Much easier is to gettem when ashore. Again, Hcl miles the best but namby brit authorities think we're all irresponsible and judging by my freely using Hcl at every opportunity, they're probablyy right...

 

[kindredspirit]

If they're Zebra Mussels, then apparently they can colonize a pipe in 2 to 3 weeks!

See here. http://www.gma.org/surfing/human/zebra.html

I hope they never congregate around my boat!

 

[BarryH]

Garlic butter................not really helping is it. Dunno never came across this before.

 

[DAKA]

Your idea of clear pipes should give you notice of the problem, we have clear metal spring reinforced pipes and they are always very clean, there is a lot of water going through that keeps them clean.

If you close the sea cocks when away for more than a week could that help as the mussels would then be in stagnant water ?

You could take the pipe off from the impeller end and add an egg cup full of acid (cheap concrete cleaner from builders merchants should do it but what a nuisance).
If the problem persists you could add a y valve to add the acid, this may also double up as an emergency bilge pump so not a complete waste of time if it doesn't work.

I have heard of eels growing in filters but not mussels.

 

[stonecrop]

The mussels must have grown within 3 – 4 weeks. The boat was out of the water for 6 months and the sea water pump was replaced as part of the winter maintenance. The cooling pipe to the pump was dry. Also, the mussels were alive. All uniform size about 32mm long. I have been out in the boat 4 times in the last 4 weeks, planning at 30+ knots which would have been a rough ride for the mussels. The filter is actually the intake grill at the bottom of the out drive leg, so not possible to shut it off outside.

 

[andy_wilson]

Co-incidentally

Mine was out for 4 months, put back and used after 3 weeks - at Easter.

Engine has been in bits over winter so after a period of gentle running, I opened her up.

Commented to SWMBO that I must have done a good job on the cylinder head as we were tramping along nicely and there was a much sharper 'bark' from the exhaust. Until the temp. alarm went off.

Flow was OK at low revs., but she overheated flat out.

Took strainer to bits to find that within the three weeks about a dozen mussels and loads of shrimpy things had grown within the strainer.