Clean thru-hull from the inside?

[Kenomac]

Not as much water comes in as you'd think. I have a 1/2 inch and a 3/4 inch through hull that I needed to clean because the strainer would become plugged up, but the valve was stiff enough that I didn't want to chance breaking it off while the boat was in the water. I expected a gush like a hose squirting me in the face, but the flow was more like what you'd expect from the outflow on the side of your boat. Give it a try, and have a bung handy. Nothing to worry about.

[Chuck Hawley]

Originally Posted by Canibul

I am thinking of closing the thru hull fitting, removing the hose, getting some kind of cleaning tool ready, opening the valve and trying to clean it from the inside. I know some water will come in, but I'm guessing not much and I could help minimize it by using a rag around the cleaning rod or bottle brush or whatever I use.

I think this is a reasonable idea. I would make sure that you had two things before starting: several options for cleaning the bore of the through hull (bottle brush, dowel, stiff toothbrush) and I would have a back-up partner along in case you are somehow incapacitated. I would hate to have a problem of some sort in a boat with an open seacock and have no back-up plan!

Come to think of it, I'd probably have one or two means of plugging up the hole should the seacock or other bit break in the process. I had a common gate valve come off in my hand due to dezinctification when I was 21, and I was very lucky to have a sponge that I could jam in what remained of the through hull.

Chuck

[HopCar]

"Wonder if anyone has run them through the ABYC gauntlet yet."

Probably not. The plastic ones seem similar to Marlon as they are glass reinforced and not brittle. They describe the material as glass injected polypropylene.

The companies Chemical Resistance Table says that Sea Water has no know effect on this material. I don't know what the physical strength is but I'm comfortable using it inboard of a good seacock.

The company we buy them from also makes them in Type 316 stainless.

It was the big sportfish guys who started using them. They use them to hook up their baitwells that need to be cleaned or change pumps quickly.

[deblen]

Originally Posted by HopCar

"Wonder if anyone has run them through the ABYC gauntlet yet."

Probably not. The plastic ones seem similar to Marlon as they are glass reinforced and not brittle. They describe the material as glass injected polypropylene.

The companies Chemical Resistance Table says that Sea Water has no know effect on this material. I don't know what the physical strength is but I'm comfortable using it inboard of a good seacock.

The company we buy them from also makes them in Type 316 stainless.

It was the big sportfish guys who started using them. They use them to hook up their baitwells that need to be cleaned or change pumps quickly.

I doubt if these would ever break,but anyone worried about these,could fit them to the strainer end of hose,above water line.

[sailormed]

Buy one of the METS innovation award winner tools for closing the through hull from the inside.
Their website Seabung.
Situated in the UK.
I have no interest in this company.

[Roy M]

Here's the bait pump sea chest pic:

[Canibul]

Thank you all for the great responses and information. I've had both propshaft stuffings completely out and so I have experienced free flowing sea water. They are deeper than this thru hull, so the pressure will be less. This thru hull feeds one line to a T, and was the raw water supply for a marine head and the aircon compressor. I've removed the head, and capped that off. I'm planning on replacing the 3/4" hose from the valve to the strainer, and discarding the old hose, T fitting, and the two hoses from the T to the strainer and former head. I'll try it first with the hose still on it and above the waterline, and can dump bleach or acid in it first to loosen things up. I've got a portable compressor so could blow it out with air.

So one of these approaches should work fine. I do worry about 30 year old valves breaking off, but will have bungs handy along with two 4000 gph pumps. And a partner.

[psneeld]

Originally Posted by HopCar

"Wonder if anyone has run them through the ABYC gauntlet yet."

Probably not. The plastic ones seem similar to Marlon as they are glass reinforced and not brittle. They describe the material as glass injected polypropylene.

The companies Chemical Resistance Table says that Sea Water has no know effect on this material. I don't know what the physical strength is but I'm comfortable using it inboard of a good seacock.

The company we buy them from also makes them in Type 316 stainless.

It was the big sportfish guys who started using them. They use them to hook up their baitwells that need to be cleaned or change pumps quickly.

We use them all the time on trash pumps and hoses for salvage.

You might just have convinced a bad boy to try it where I am.

[Canibul]

Originally Posted by sailormed

Buy one of the METS innovation award winner tools for closing the through hull from the inside.
Their website Seabung.
Situated in the UK.
I have no interest in this company.

Well, I bet you wish you did.

Pretty slick little gadget. Do they make a scrubber version?

[Hudson Force]

Over the 45 years I've been cruising I've taken hoses off closed through hulls and set things like coat hangers, wood dowels, screw drivers, etc.. into the piping wrapped within a rag and cleared many obstacles. I always gently slide the end past the ball value before any forceful reaming and I've never had a problem. I've also removed and replaced threaded ball valves on some through hulls in the water with just a small amount of water entering. It's also quitr easy to open a hose above the waterline and sometimes force a plastic bag or sea weed from a through hull cover with a puff of air from lung power alone.

[Canibul]

wow. imagine a 41 ft hookah....

Sorry, couldn't help myself. The image of me blowing on the 30 year old hose to the former head just brought up this image of one of those big old Turkish water pipe things. I don't think this is that kind of obstruction. I think this is little marine things growing inside the teardrop shaped external grill. It's one of those standard slitted bronze things, battered and bent and been on the boat forever. I am seriously thinking about removing it, like PSNeeld reports, until I can get some of the Groco strainers. I don't see that the present one is really doing much good and it seems to turn into a micro version of a reef ball when the boat sits still for a while. New bottom paint this year, so I'm guessing there's no new paint inside the external strainer.

I also wonder if I need one at all, since the water goes through a big pancake canister type strainer before the pump.

Thanks for the useful info and encouragement. Much appreciated.

[Hudson Force]

Originally Posted by Canibul

wow. imagine a 41 ft hookah....

Sorry, couldn't help myself. The image of me blowing on the 30 year old hose to the former head just brought up this image of one of those big old Turkish water pipe things. ..................
...........

Whoa,- LOL... 'not the image I wanted to present!

I agree that you need to be selective with your tools. When I use lung power to blow on a hose, it's usually a "cleaner" choice and not for attached marine growth.

I will admit that, for the crustaceans or mollusks on the grill coverings, I select something like a coat hanger that is small enough to fit through the slit openings; however, I spend my time in waters that are warm enough and clean enough to dive under for a better job.

[Terra Nova]

Originally Posted by Roy M

Here's the bait pump sea chest pic:

Sorry, but that is one of the most dangerous installations I have seen in a boat. With that much leverage, the slightest knock could break it off and flood the boat.

[Canibul]

Originally Posted by Hudson Force

I will admit that, for the crustaceans or mollusks on the grill coverings, I select something like a coat hanger that is small enough to fit through the slit openings; however, I spend my time in waters that are warm enough and clean enough to dive under for a better job.

yeah, we do too, normally. But we're refitting this boat at the moment and it's staying dockside and I absolutely hate to swim in the marina. Any marina, but here especially. You see, there are no rules on what goes overboard in the marinas here. There is no enforcement, if there were rules. So, the three local fishing boats tied up about 40 yards behind us are undoubtedly dumping directly overboard. There are no other facilities for them to use. The marina is on a dead end canal. Not well flushed by the very small tides here. You see what I mean. Not everything floating in this water started out there.

I also worry about stray electrical current in marinas. I've heard some heart attack horror stories. But my main concern is water quality.

If we were on the hook, I would have already been over the side. My reluctance to do so while tied to the dock is what made me ask myself if I could do it from inside the boat. Obviously, it's no big deal. Good news.

[Canibul]

For followup, and for anyone who finds this thread, this is what happened. I raised the free end of a hose connected to a T between the thru-hull and the strainer. This is the hose that once fed the marine head. I had put a valve on it to close it off while I decided what to do with it.

With the open end above sealevel, I poured about a cup of muriatic acid into the hose, and then closed the valve. I figure that was more than enough to completely saturate the little bit of seawater in the hose. It's half inch ID and about four feet long. I let it sit for about an hour, and then fired up the aircon and pumped it all out.

That cleaned it out. The flow from the aircon compressor cooling circuit is a solid stream again. Whatever was clogging it is no longer clogging it.