Our AC's have a UTI or something...:(

Hubby went to check on the boat this evening and it's barely pee'ing.
He checked the sea strainer and it was clean.
He did a few other things and discovered there is barely any water coming in through the thru hull. He explained to me what he tried to do but said it didn't work.

He turned the units off and came home.

Bummer. No AC on the boat for now u til we figure out how to fix it.

Try blowing the thruhull out with a water hose or compressed air.

Close throughull, disconnect hose, jam rod down through the throughull, water hits face, close throughull, reconnect hose.

Make sure you bleed water through pump or it may overheat depending on relative heights of strainer and pump.

I suspect the warm brackish water of Madisonville have caused marine growth to obscure the through hull thus restricting the water to the pump. Welcome to boating in the warm nutrient rich waters of the south

We keep our boats in the proverbial primordial soup, Swan Creek, MD. Once had something wonderfully dense growing in the engine raw water intake. Check and clear the intake throughhull of whatever's growing in there.

I've opined that perhaps the throughhull/seacock could be arranged so that removing a plug in the end of a tee would allow a straight shot at rodding it out. The seacock, if a ball-type, would be rod-able and easily closed before and after the removal/replacement of the plug. The side tap of the tee would lead off to the internal strainer.

Those of us with external strainers integral with the throughhull would not profit by this idea.

WEAR gloves when clearing a thru hull, some jelly fish can sting , even in pieces.

Thank you all for the suggestions, I've tried a few last night. Will try others this weekend when I can get back to working on the boat. But maybe a system description would be a good add to this thread. I will start off with:
Our boat is in the fresh water of the Tchefuncte River and nasty green stuff grows on any surface in this water for longer than 10 minutes
I don't know what type or even if there is a screen at the thru hull inlet
I am not diving in the marina water to find out
From the valve on the thru hull it is hard piped up to a 90 that goes directly into the metal housing of the sea strainer
My hose nozzles don't fit into the sea strainer opening to get a tight fit to the pipe opening to flush the inlet back through the valve
Neither does my shop vac hose
Tubing pipe cleaner, other plastic tube, spare piece of wire, etc that I had handy last night either can't navigate the 90 or get through the ball valve
So I gave up last night, closed the valve, came home and fixed a drink
I will now either modify a fitting that I can attach the hose to that will fit the opening, disassemble the outlet hose and back flush throug the strainer housing, disassemble the hard piping and flush directly through the valve, or take the boat out to clean water to try and dive underneath and clear the obstruction.
At least that is plans A, B, C, and D

boatpoker said:

Close throughull, disconnect hose, jam rod down through the throughull, water hits face, close throughull, reconnect hose.

Click to expand...

LOL...NOW I understand your TF name...

Try one of these fittings it should fit the pipe if not cut the tip off or grind it down, WMT or a hardware store should have one. They are made in plastic too, plastic may be easier to jam in to the pipe for a tight seal. The same store will probably have a plastic, or metal on/off valve to screw on to the nozzle that would make things easier.
Brass Sweeper Nozzles - Manufacturer, Supplier
Good luck

In addition the the sea strainer issue don't forget about the coils.
Been an ongoing problem for me here in SW Fla.
*Clean sea strainer
*Close sea cock fill with Barnacle Buster and let sit over night then flush out
*Use a recirculating pump to push Barnacle Buster through entire system for 4-6 hours.

Recently cleaned my strainer but still was not cooling like it should. I flushed the system this way and vent temp dropped by 7 deg!
I've used this stuff for years on my engine coolers with fantastic results

As others have advised, you are probably getting sea growth on the outside of your raw water pickup and you need to back flush. Since this is probably a recurring problem, I would set up a semi-permanent system to backflush.


Install a tee right after the elbow on top of the thruhull. Then connect ball valves on both ends of the tee- the straight through end that goes to the pump and the branch with a hose adapter on the branch valve. That way you can isolate the pump and connect a garden hose to the branch.


If the growth is really bad, back flush every time you use the boat. Shouldn't take more than a few minutes if set up as above.


Then after the raw water supply is clear, check A/C air temps. You should get at least a 15 deg drop between the air register outlet and the return air. Any less is an indication of low Freon or raw water system fouling. You can flush with Rydlyme, Barnacle Buster, etc to remove the fouling.


David

No experience with boat cooling systems, but plenty of experience with plumbing and marine growth. Someday I hope to remedy the lack of boat cooling experience. So how common is the clogging of through hull piping systems? Is it a once a year thing or a once a week thing? You guys sound like you have pretty established procedures and that makes me think cleaning strainers or fittings where there should be a strainer quite common.

If a guy like me were thinking ahead about what to add to a boat he expected to spend a year at a time on, how would you proactively design seacocks and their associated fittings to make this job easier?

DHeckrotte said:

I've opined that perhaps the throughhull/seacock could be arranged so that removing a plug in the end of a tee would allow a straight shot at rodding it out. The seacock, if a ball-type, would be rod-able and easily closed before and after the removal/replacement of the plug. The side tap of the tee would lead off to the internal strainer.

Click to expand...

This is the configuration we used this spring for a new generator install.

HeadedToTexas said:

No experience with boat cooling systems, but plenty of experience with plumbing and marine growth. Someday I hope to remedy the lack of boat cooling experience. So how common is the clogging of through hull piping systems? Is it a once a year thing or a once a week thing? You guys sound like you have pretty established procedures and that makes me think cleaning strainers or fittings where there should be a strainer quite common.

If a guy like me were thinking ahead about what to add to a boat he expected to spend a year at a time on, how would you proactively design seacocks and their associated fittings to make this job easier?

Click to expand...

Depends largely on where the boat is, and marine growth and/or slime build-up in that area... so probably no single answer.

Groco crash valves (safety seacocks) or similar would offer an easy method to clean in either direction. OTOH, that would often require a refit. OTOOH, crash valves have their own uses, too.

Their safety seacock conversion (SSC) with flush adapter isn't quite as elegant, but it's also not as expensive and can be fitted to existing seacocks. We have the conversion on three of our four major intake seacocks (two mains and AC; genset seacock on the to-do list).


The rest of an AC plumbing system can stand occasional cleaning too; products like Rydlyme or Barnacle Buster work well for something like that.

-Chris

Were water comes out of strainer to pump,make up a hose to barbed to correct size hose ,so you can back flush the strainer to outside thru hull fitting. This will blow away the outside alge. Put a 3"chlorine pool tap into strainer and let it resolve thru the system. This will help kill any alge growth in the lines. When you get to clean water inspect the thru hull for blockage. Each time I clean my a/ c strainer I add a 3" tab to kill the growth within the lines. Living aboard in the keys at this time of year, the tap dissolves quickly and I have found no problems. We also get a lot of bay grass ,so I cut 6" of a 5 gallon bucket drilled many 1/2" holes and attached it to the outside of the thru hull with a wire tie. This keeps most of the grass out of the strainer. Of course I remove it if we go cruising.

Hey Star, what's the water level doing at the marina?
Wondering when we do get a boat if it's worth it to get a floating dock or how much rise will cause a problem?

folivier said:

Hey Star, what's the water level doing at the marina?
Wondering when we do get a boat if it's worth it to get a floating dock or how much rise will cause a problem?

Click to expand...

The water level isn't up...at least not yet.
When we had the floods earlier in the year the marina flooded (before we bout our boat). The docks were underwater but everybody's boats did just fine with a bit of line adjustment so I was told when I asked about that.

So apparently something must have gotten stuck or sucked up against the thru hull. Hubby went to go work on it this morning and he opened the valve and water came rushing in. It's all working properly again. Apparently turning it all off and releasing the suction allowed whatever was stuck to get unstuck.

Glad it wasn't a real problem.

Good, maybe an old ice, or other, plastic bag. There are plenty of them drifting around.
Stll a good idea to carry something to blow or flush it out with, jellyfish can be a problem too they don't fall of so easily.

Thanks Star. I was looking at the river gage above Covington but good to know that the level is lower closer to the lake.

folivier said:

Thanks Star. I was looking at the river gage above Covington but good to know that the level is lower closer to the lake.

Click to expand...

We're monitoring the situation. It's so bad all around us. My daughter is trapped in her apt in Baton Rouge. Her apt. Is not flooded but the streets all around her are impassable.

I was just reading a fb post from Livingston parish that they are sending a Blackhawk helicopter to help with rescues. People are trapped on their roofs and posting on fb begging to be rescued because they can't get through to 911.

It's a horrible situation.

Deckape said:

Were water comes out of strainer to pump,make up a hose to barbed to correct size hose ,so you can back flush the strainer to outside thru hull fitting. This will blow away the outside alge. Put a 3"chlorine pool tap into strainer and let it resolve thru the system. This will help kill any alge growth in the lines. When you get to clean water inspect the thru hull for blockage. Each time I clean my a/ c strainer I add a 3" tab to kill the growth within the lines. Living aboard in the keys at this time of year, the tap dissolves quickly and I have found no problems. We also get a lot of bay grass ,so I cut 6" of a 5 gallon bucket drilled many 1/2" holes and attached it to the outside of the thru hull with a wire tie. This keeps most of the grass out of the strainer. Of course I remove it if we go cruising.

Click to expand...

Try bromine tabs. Smaller (1"), slower dissolving and less corrosive than chlorine.

Capt.Bill11 said:

Try bromine tabs. Smaller (1"), slower dissolving and less corrosive than chlorine.

Click to expand...

what is chlorine corrosive to? Does it affect copper?

Reason I ask is, my slip neighbor just tried a couple pieces of copper pipe in his screen, and is going to try the bromine. Surprisingly the (2) 1/4" x 3" copper pipe pieces that he put in his SS screen were actually etched after 1 week of continuous use.

As best I can tell the copper pipe pieces were etched by the salt water alone. And that strikes me as really bad since the A/C's condenser is made from copper tubing.

what_barnacles said:

what is chlorine corrosive to? Does it affect copper?

Reason I ask is, my slip neighbor just tried a couple pieces of copper pipe in his screen, and is going to try the bromine. Surprisingly the (2) 1/4" x 3" copper pipe pieces that he put in his SS screen were actually etched after 1 week of continuous use.

As best I can tell the copper pipe pieces were etched by the salt water alone. And that strikes me as really bad since the A/C's condenser is made from copper tubing.

Click to expand...

The tubes should be cupronickel.

Metals and Corrosion Resistance
M

Interesting paragraph on wikipedia in regards to cupro...

In seawater, the alloys have excellent corrosion rates which remain low as long as the maximum design flow velocity is not exceeded. This velocity depends on geometry and pipe diameter. They have high resistance to crevice corrosion, stress corrosion cracking and hydrogen embrittlement that can be troublesome to other alloy systems. Copper-nickels naturally form a thin protective surface layer over the first several weeks of exposure to seawater and this provides its ongoing resistance. Additionally, they have a high inherent biofouling resistance to attachment by macrofoulers (e.g. seagrasses and molluscs) living in the seawater. To use this property to its full potential, the alloy needs to be free of the effects of, or insulated from, any form of cathodic protection.

Click to expand...

It seems that you shouldnt use a pump that pushes water real fast through the pipes or the corrosion resistance lowers? How fast is too fast?

And it also seems that you shouldnt bond the pipes to the boats bonding system. I never would have guessed that one.

what_barnacles said:

Interesting paragraph on wikipedia in regards to cupro...



It seems that you shouldnt use a pump that pushes water real fast through the pipes or the corrosion resistance lowers? How fast is too fast?

And it also seems that you shouldnt bond the pipes to the boats bonding system. I never would have guessed that one.

Click to expand...

The a/c system is grounded through the panel and there is (ABYC) an ACground - DCnegative bond at the panel. If you also have underwater metals bonded (ABYC) you cannot isolate the a/c from the cathodic protection system.

With the boat wired to ABYC standards isolation from the cathodic protection system would, I think be impossible. I also don't see how a cathodic bonding system could interfere with the biochemical reaction (anti-fouling properties) of copper and marine growth.

Wikipedia is a great resource but I'm a little skeptical on this one (and a few others on Wikipedia)

Galvanic Properties

Copper-nickel alloys lie mid-way in the galvanic series being compatible with other copper alloys but more noble than zinc, aluminium, steel and aluminium bronze and less noble than passivated stainless steels, nickel alloys and titanium. The 70-30 alloy is slightly more noble than the 90-10 alloy. As with all bimetallic couples careful attention should be given to avoiding unfavourable galvanic area ratios.

Galvanic contact with less noble copper-alloys, carbon steel and zinc negates the biofouling resistance of copper-nickel. Therefore, in applications requiring the full biofouling resistance of copper-nickel, such as boat hulls, the use of anodes and impressed current cathodic protection systems should be avoided.


https://www.copper.org/applications...ion/corrosion_resistance_and_antifouling.html

Not pretending to know anything about cupro nickel corrosion...

what_barnacles said:

Galvanic Properties

Copper-nickel alloys lie mid-way in the galvanic series being compatible with other copper alloys but more noble than zinc, aluminium, steel and aluminium bronze and less noble than passivated stainless steels, nickel alloys and titanium. The 70-30 alloy is slightly more noble than the 90-10 alloy. As with all bimetallic couples careful attention should be given to avoiding unfavourable galvanic area ratios.

Galvanic contact with less noble copper-alloys, carbon steel and zinc negates the biofouling resistance of copper-nickel. Therefore, in applications requiring the full biofouling resistance of copper-nickel, such as boat hulls, the use of anodes and impressed current cathodic protection systems should be avoided.


https://www.copper.org/applications...ion/corrosion_resistance_and_antifouling.html

Not pretending to know anything about cupro nickel corrosion...

Click to expand...

From the link you provided (seems like a legit site) .....

Galvanic contact with less noble copper-alloys, carbon steel and zinc negates the biofouling resistance of copper-nickel. Therefore, in applications requiring the full biofouling resistance of copper-nickel, such as boat hulls, the use of anodes and impressed current cathodic protection systems should be avoided.

Splash zone sheathing on steel offshore platforms in 90-10 copper-nickel should at least span from below mean tide level to well into the atmospheric zone. Potential galvanic corrosion on the adjacent steel is addressed by coating the top section with paint; the bottom, submerged junction will be protected by the cathodic protection system normally applied to the structure.

I'm confused, this makes little sense to me and seems like multiple contradictions and I am a certified corrosion analyst.

I think what they are "trying" to say is, the copper wont get the initial corrosion layer that is the primary protection against slime and stuff if it's electrically connected to a less noble metal, like zinc. The zinc keeps it from corroding and negates the whole purpose of using cupro (biofouling resistance).

Thats why I posted in the first place. I hadnt heard of that before.