In a RIB I just bought the bilge pump didn´t work so I took out the water and discovered this! It can be either from freezing (?) or from the petrol (?) that was in the bilge water. Have you seen something like this before..? It seems to have been the pictured Attwood pump.
Hi, I would hazard a guess it is caused by the alcohol in the petrol ( gasoline) that it sat in for an extended period.
i'd check the float switch... seems to me like it stayed stuck on for hours and hours, or days and eventually melted down. is the breaker properly sized?
This was my first impression too, but I can not see it happen this way really, as it must have stopped running long before this stage. There is no smell or sign of burnt plastic either, it is just deformed. The breaker seems to be OK, with a red light coming on when pushed for manual pumping. The float switch is moving freely, but I have not tested it yet. I guess K1W1 could be right, the twisted shape does not really fit with freezing water. On the other hand I thought a bilge pump could survive petrol, but perhaps not if it contains alcohol.
That's heat damage, nothing else would soften the plastic up to do that, aside from highly concentrated petroleum products. Certainly not fuel in the bilge.
Hi, I think if the float switch had got stuck and it ran till it stopped the top of the pump would be a bit browner than it is in the photo. The bilge might have been full of a water gas mix when AMG got his boat but who are we to say it hasn't been full of something nasty previously that attacked the plastic.
Wouldn´t the heat have been around the motor and not in the bottom, what you see in my pictures is now upside down..? EDIT; K1W1 posted similar thoughts when I was posting. But I think it is only petrol that has been there, perhaps more petrol than water at one stage...
Hi, Look what Ethanol blends have done to fuel tanks in Fiberglass boats, I remember years ago when the first blends started arriving in NZ there were lawnmowers and cars catching fire from split hoses so no reason to think that the alcohol wouldn't feast on plastic components as well.
I would definately rule out freezing and heat. I would have to say it sat in gasoline or some other similar chemical to soften the plastic like that. If it was heat I would think there would be scorching on it. I would definately check your fuel tank for any leaks. Is it also possible the owner filled the bilge with water and alcohol or something similar for some kind of winterizing effect, not that I would consider that, but I've seen owners do all sorts of weird things.
The pump was at half in this water/fuel mix and it could be the 5% ethanol we have in gasoline that caused it over the 6-8 months storage. I must check the fuel tank for leaks too, it doesn´t seems so, but the fuel must have come from somewhere...
Hi, Just get a couple of litres of gas and leave the pump in it for a few days , see if it changes the structure of the pump casing by making it pliable or brittle. Please exercise the sensible precaution about no naked flame when you have this open container of gas
Thanks K1W1, but at this point I am fairly certain it has to do with the fuel. I have just sent an e-mail request to the boat builder in England to find out how the tank is built in and if ethanol can be the culprit even there. Or it can be a crack or leak at a connection...
Hi, An English Boatbuilder - Good luck. We have a large RIB under construction in the UK right now - It is currently 7 months late - not bad for what was supposed to be a 12 month build contract. I just hope it is finished before the mothership or there will be some slight unrest from the client to put it mildly.
Well, he was behind this boat but I don´t think he is building them now. They use them for training today I believe... http://www.powerboatcentre.com/index.htm
Can you post a picture of the inside of the black plastic intake screen? Wondering if there is scouring from the impeller. I've seen pumps where the impeller rubbing on the intake screen generated heat & caused them to deform like that. Sure looks like heat damage from friction,not heat from the motor..... Also there is a clean break/crack that can be seen on the outer/upper edge of the intake screen. Did that happen during disassembly? If not maybe the pump was dropped or asbused and the break in the plastic intake allowed the impeller to rub. The other thing that is puzzling is some of the melted vanes are folded over in different directions. I would think they all would all be folded backwards, consistent with the direction of rotation. So K1W1 could be right.
Hi, That bit on the bottom of the pump is actually the pump outer casing, the impeller is behind this cover.
K1W1 is right, again, the impeller is the white "fan" inside the greyish casing and the black is out of reach. Thanks all, I am moving over to the tank to find a leak now...