protection for alternator

Home Forums Deck and Hull Cockpit and Engine Room protection for alternator

This topic contains 9 replies, has 5 voices, and was last updated by Voltair Voltair 6 years, 9 months ago.

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January 12, 2012 at 13:56 #5651
Ronar M
Ronar M
Participant

When I leave my boat I close the cockpit drain seacocks in case there is a failure in the pipework when the Ronar M is unattended. Although I have a new cockpit canopy,which leaks a lot less than the old one, water still gets into the cockpiut in small amounts and cannot drain away. Eventually when the pipes and gutters are full, water gets into the engine bay. The result is that my alternator looks as if it’s been through Noah’s flood. It still works ok but I worry about the state of it – all corroded and rusty in places. I have had the idea of fixing a plastic shield (possibly screwed to the underside of the cockpit floor supports) to shed the drips and protect the alternator. Has anyone else done a similar thing and has it worked? Cheers, Trevor

January 12, 2012 at 19:22 #10921
Moderator
Moderator
Keymaster

Rainshadow’s setup is completely different, which means we do not have this problem. The PO rerouted all cockpit drains to the bilge (seacocks are probably corroded closed by now, so we’ve kept this arrangement since to date we’ve only sailed in protected waters with limited chance of boarding waves). We have a small automatic diaghram bilge pump that gets rid of this sort of low level water accumulation. We also have cockpit canopy that keeps out 99.9% rain.

My thought is – assuming your bilge is fitting with an automatic bilge pump, how about having a secondary cockpit drain system that dumps rainwater to the bilge so you can avoid flooding your engine bay? Not sure how to add this secondary system, but I think I would go after solving the accumulating rain water problem first. It cannot be good for anything to get regularly soaked.

January 13, 2012 at 15:42 #10951

Rhapsode
Participant

I’m having the usual Nic 38 problem of water coming in through the cockpit drains. I find that the main drains from the top of the cockpit floor are not as troublesome as the water bubbling up into the channels around the edge of the engine space under the cockpit floor since they are a little lower. The original owner of the boat put ping pong balls in the main drains themselves which may contribute something to dampening down the water ingress from them but I still get wet feet! More importantly, I lost the heater when the water from the underside channels bubbled up and over on to the heater electrics. I opened up the cockpit floor and saw a “curtain” of water flooding over and into the engine space and onto the electrics.

Since I am finally getting round to fitting an automatic bilge pump switch I am considering changing the under cockpit floor channels so that they drain into the bilge and closing off their seacocks permanently. We’ve had a few lumps of sea in the cockpit and it seems to drain away reasonably quickly. I don’t think that the underfloor drains contributed a great deal to the draining so I am not so concerned about their loss as much as I am about causing a fire due to shorting electrics.

The end result will be that the main drains go into the sea as usual with the lower ones going into the bilge. This means that when the boat is unattended (with the seacocks closed) rain water will find its way into the bilge where it will be taken care of by the pump. When we’re at sea the main drains will take the lion’s share of draining the cockpit.

Slightly off message – I was reading an earlier post about drains and picked up on the point that the drain hoses should not be of plastic since they will melt in the event of a fire in the engine space. That job is now on the the top of my list for the very next dry dock.

Peter

January 14, 2012 at 21:15 #10961
Chihili Q
Chihili Q
Participant

Chihili Q’s weakest point was the bilge pump outflow pipe, up which seawater siphoned on port tack rather freely; since I installed a one way valve the issue seems closed.

Ludi, her PO, installed a second set of cockpit drains, unimpressed by the original drains capacity to empty her cockpit efficiently. I think this may have been a mistake; now I have four through hull fittings each of which connects to two drains either under the cockpit sole (the originals) or above (the newer intallations), and each tends to reflux back up their plastic pipes. My medium term intentions are to 1) put in one way valves to keep my feet dry 2) maybe decommission 50% of the current drains 3) replace plastic with ?copper or clad them in asbestos.

That “curtain of water” falling into the engine bay on opening the cockpit sole hatches maybe testifies to their water-tightness, since the water seems to have been held back until you lifted them! I have taken some pains to ensure Chihili Q’s under sole seals are effective, and we have had previous correspondence in this forum on how best to lock those hatches down to secure a good seal.

Regards, Adrian.

January 15, 2012 at 01:06 #11011
Moderator
Moderator
Keymaster

I’m a bit confused by the description of “main drains from the top of the cockpit floor”. In Rainshadow, the drains are not visible when the cockpit sole doors are closed. The only floor drains are in the channels just below the sole doors. There are also some drains at the cockpit locker seat level on both sides. There are channels molded into the FRP to guide the water to these seat-level drains.
Rainshadow is hull# 126 – I am wondering if there were some design changes over the build-run, which means we have different designs (or perhaps differently creative POs?).

For anyone who has “sole-level drains” – could you post a photo?
Cheers –
Marilyn

January 15, 2012 at 13:02 #11021
Chihili Q
Chihili Q
Participant

The first photo shows the additional drains through the cockpit sole, two on each side which connect through a Y piece to piping that traverses the engine bay (as shown in second photo) and drains through a hull fitting the opposite side. As you can see, lots of piping everywhere and all of it vulnerable to fire!

The third photo shows the image of an original cockpit drain and its mirror image which reveals cracking of the glassfibre collar where it enters the copper piping, which in turn attaches to the original drainpipe which then passes to a Y fitting and then to an ipsilateral through hull fitting. I think this contributed a fairly constant trickle into the engine bay at times.

Regards, Adrian.


January 15, 2012 at 17:22 #11041

Rhapsode
Participant

Adrian,

I first discovered the problem when the heater switch in the main cabin started to smoke! I traced the short circuit back to the engine compartment where Rhapsode’s heater is located (where your batteries live). This suggests that water was running off before I opened up the hatches so I need to follow your advice and seal the lids down more effectively. We were in bouncy weather at the time.

Before I read of the fire risk to plastic hoses I had bought two plastic non-return valves to fit to the bigger drains. The underneath ones won’t need them now that I intend redirecting them to the bilge. I will now have to now source metal replacements but I am also now wondering whether they will be affected by the heat when the engine is running and start to stick. Any thoughts on this would be most welcome.

The other related issue is that the bilge pump hoses run up from the bilge and across the engine compartment. I’ll have to make some arrangement to make these fire proof as well – probably exhaust cladding from the local garage would do.

Peter

January 17, 2012 at 08:02 #11071
Ronar M
Ronar M
Participant

Hi All

As I started all this off I thought I had better comment. The discussion seems to have developed into two other issues – water coming up the drain pipes and wetting people’s feet and fireproof pipework. In 11,000 miles aboard Roanr M we have never had water coming up the cockpit drains. As far as I know the arrangements on on Ronar are standard and the pipework is not crossed over. Perhaps we have just been lucky. However, I replaced all the pipework with fireproof rubber some years ago in order to achieve Ronar M’s commercial status. There is a British (European?) standard for fireproof pipework and I will try to get product numbers etc next time I am on board and let you know what it is. Also for my commercial licence I had to seal the cockpit floors. I did this by gluing neoprene rubber on to the fibreglass seating of the floors with special two part neoprene glue and this has proved successful in reducing the rainwater getting into the engine bay and cutting down engine noise. I also had to plane 4 or 5 mm off all the edges of the cockpit floors to allow any water to drain quicker (there is an industry standard for the relationship between cockpit volume and drain area). Cheers, Trevor

March 7, 2012 at 20:53 #11321
Voltair
Voltair
Participant

I think the reference to flammability and vulnerability of all these drainpipes was probably a comment we made long ago when Peter in the Med was re-doing his drains.

On Voltair, we are so concerned about our drains that we shut them off completely. In our opinion, the dia of the original drains are completely inadequate, and the cockpit floor is also at least 2-3 inches lower than desirable to give adequate freeboard above the drain level. (or else Voltair is 2-3 inches lower in the water than she should be!) If ever we got a massive wave aboard that filled the cockpit, it would now drain into the cabins and thence to the bilge. We hope we could pump it out from there, but if there were one or two more waves that followed the first, we feel sure the yacht would be depressed by some inches and the original drains (were they open) would then cause the vessel to sink rather than drain. Therefore we are actually considering raising the cockpit floor by about 4 inches (with all the horrible hassle that will entail) and fitting 2 x 3-inch diameter drains on each side of the cockpit, so that in the event of a real dump, we have a chance of draining the water back to sea rather than sinking.
But we are only considering this over a pint at the pub tonight…. with Voltair far away in Portugal, making it happen is somewhat further away as yet.

March 10, 2012 at 14:35 #11331
Voltair
Voltair
Participant

But all this is far away from the original topic, protection of the alternator. Yes, we also have the problem of water dripping from the under-floor crossmembers. If we suspect we are going to get a lot of rain, we just put some sheet plastic over the front of the engine when we are shutting things down to leave the boat.

Having come back from the Pub, we are now considering some kind of lateral drain channels, maybe 6″ long and 2″ tall, going through the side lockers and exiting the hull at a level about 4″ above the floor (when on an even keel) with hinged flaps to allow water out but not in. These would be ducted through to the internal cockpit walls at the same height. In this case, we might not need to raise the cockpit floor at all, because once the water got high enough in the cockpit, (or the boat was heeled a bit), it would mostly run out of the downhill side into the sea. All the old sailing ships used to have them, I gather. But we would need to use the taller toe-boards to block the companionways, which our previous owner had made under recommendation from the authorities.

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