Blocked heads inlet - any ideas?

[samfieldhouse]

Annoyingly the boat was out of the water a couple of weeks ago. And a week later following a stay in a very weedy Newtown Creek, the inlet appears to be blocked.
With the inlet pipe disconnected from the seacock and popped in a bucket of water, the heads pumps fine. So all the plumbing between the seacock and the heads is fine.
With the inlet pipe disconnected I've scraped around inside the seacock and removed some weed.
With a length of pipe connected to the seacock I've both blown with the dinghy pump and sucked with a manual hand bilge pump.
With the bilge pump I'm sucking a very small amount of water through, and with that pipe held below the water line there is no water gushing through.
With the seacock open I've also poked a length of wire down but it doesn't seem to get further than the seacock.

So my assumption is something is well bunged into the inlet between the seacock and the sea.

I even wondered if the seacock was stuck closed, but the blockage occurred whilst pumping - and when she was out of the water I greased the seacock and could see it opening and closing form outside.

I'm assuming I'll just have to dry out and poke from the outside, but any thoughts appreciated.

 

[rogerthebodger]

I had a blockage in an engine inlet once and used a scuba tank to clear the blockage

 

[samfieldhouse]

I wonder if I can persuade the marine team at work they need some 'training'?

 

[vyv_cox]

You could use one of your wooden wedges just too small for the opening and push it outwards. If it displaces anything there will be very little ingress of water. Have a rag handy to clap over the opening.

 

[wingcommander]

Could you sea sea cock opening and closing with inlet pipe disconnected?

 

[samfieldhouse]

Could you sea sea cock opening and closing with inlet pipe disconnected?

When she was out of the water a couple of weeks ago yes.

I know I need to be brave and do the same with a hose disconnected.

 

[wingcommander]

Yes it will confirm blocked inlet or valve failure. If either it won't sink you.

 

[david_bagshaw]

remove hose rod it out with a screwdriver. suprisingly little water will come in...

 

[tjbrace]

I have this problem too. In my case the operating lever shaft has sheared off leaving the sea cock closed.
It will stay that way until layup unless something else goes wrong. We can still use the heads by filling from the fresh water tanks. The heads outlet still functions ok.

 

[samfieldhouse]

There is a small amount of water being sucked in with the seacock open, and with the pipe off and the seacock in the 'closed' position there was no water ingress so I'm fairly sure it's opening and closing.

Will be brave and stick something through...

 

[PaulRainbow]

There is a small amount of water being sucked in with the seacock open, and with the pipe off and the seacock in the 'closed' position there was no water ingress so I'm fairly sure it's opening and closing.

Will be brave and stick something through...

Nothing too brave about it, what do you think happens when people pull the 2" paddle wheel sensor ? You don't get a torrent of water, nothing you can't easily stop by putting your hand or a rag over the hole. Just keep something handy to jam in the hole if you need to.

 

[Pye_End]

Use a dinghy pump on the end of the hose to blow the blockage back out.

 

[wingcommander]

Sounds like the bloke you anchored too close to got revenge with his polythene bag .

 

[samfieldhouse]

Use a dinghy pump on the end of the hose to blow the blockage back out.

That hasn't worked!

And yeah never pulled my paddlewheel out either...

 

[fisherman]

A wire will often just pierce it and go through, weed or plastic bag. Get a tube, alkathene, polythene, small enough to go through, long enough to clear the hull. Cut saw teeth all round one end, push and twirl it through and retract sharply. should leave the stuff behind.

Oh, and the smear peanut butter round your mouth and tell everyone you've sucked the pipe clear.

 

[davidej]

A sheared shaft on a ball valve is quite common. The handle moves but the ball doesn’t.

This happened with the outlet valve of our holding tank. I will spare you details of what came out when we fixed it !

 

[Birdseye]

Use a dinghy pump on the end of the hose to blow the blockage back out.

The classic is to use the aerosol fog horn to blast the crud out of the seacock

 

[samfieldhouse]

Tried blowing air in to no avail.
It happened mid pump so don't think the seacock is half closed/open.

 

[jwilson]

I put new all new Italian bronze and S/S handle (not el cheapo DZR or brass) seacocks and skin fittings in about 6 years ago. The manufacturer was a recommend from a surveyor. After 3 years one blocked: handle turned but internal ball didn't. Replaced seacock whilst boat was afloat, interesting job and slightly damp but not that difficult.

I am told that those bronze valves often had plated brass balls. The new bronze valve from the same supplier that I fitted had a plastic ball.

 

[Daydream believer]

You have probably collected some polythene, weed or even a fish. It could be that, although the ball rotated on dry land, the handle has come loose & is just rotating on the shaft, thus jamming the obstruction further. Has the nut come undone?
You could remove the handle & grip the shaft with a set of mole grips to check that the square section on the handle has not become rounded.
I am of the opinion that #15 is the best solution . Possibly using a short length of 12mm dowel. Once cleared, the ingress of water will not be excessive & you can have the hose ready to put back on, if the ball valve does not shut off completely.
The heads inlet pipe is usually a lot smaller than the paddle wheel outlet on a log. So there will be proportionally less water so there will be proportionally less water to worry about.