Barnicles on glass of Graco Strainer

[glcalahan]

I have lived aboard a total of 27 yrs but have been off boats for 15 yrs. I remember putting bleach tablets in the strainer and it helped keep them in check. Has anyone else done this or anything similar? I have a Graco for both engine intake and AC intake. Could it be caustic for a marine AC copper tubing??

Thanks in advance!

[Jim Cate]

FAscinating! I've lived aboard and cruised for the last 33 years and owned yachts for a decade more, and never had this problem... nor heard of it for that matter. I'm surprised they can survive in that environment... seems that it would lack the flow of food-bearing water most of the time (engine not running).

I suppose that introducing bleach (sodium hypochlorate) would discourage them, but what a PITA to do every time you shut down the engine!

Jim

[glcalahan]

Thanks.....so in all those years you never had barnicles grow on the inside of glass/plastic strainer??? Wow....cool. I have lived in both brackish and saltwater..(25+ yrs) and have often had an issue. You are lucky!

Anyone else??

[Jim Cate]

All my experience has been in salt water, starting in SF Bay and carrying on to Mexico and the South Pacific. Quite a few years in Aussie waters, from the tropic north to the cold waters of the Southern Ocean... and nary a barnie in the cooling system circuits, but plenty on the hull.

Most peculiar! Whereabouts are you sailing?

Jim

[s/v Jedi]

This is an issue in the Caribbean as well. Our procedure is to first back-flush with fresh water, then pull the strainer mesh out, stick a dish washing brush in which has a plastic back for scraping, then again back flush to get all the dirt out through the seacock, then when we’re happy, stick in a clean mesh and we’re done. The other mesh we clean afterwards.

For back flushing we have added a valve to our fresh water supply

[a64pilot]

We get the hard growth too. Mostly just scrape it off, but Muratic acid boils it right out, I won’t do the chlorine / bromine thing as it will eat your heat exchanger, both are very strong oxidizer’s and oxidization is corrosion.
Get most of the water out, pour the muratic acid in. Let it boil and it neutralizes into salty water.
I believe all my strainers are plastic though not glass.

[a64pilot]

Jim, most people use bromine sticks meant for hot tubs, just put a stick in the strainer every now and again.
It does work here for air conditioning which is a real pain to keep clean, but I won’t do it as I’m afraid what it will do to the AC condenser.
I may next year because this year keeping the systems clean was a real pain.

The hard growth is even in the AC itself, must be cause the muratic acid / water solution boils, and I believe that pretty much takes calcium to make it do that?

[thinwater]

If you turn the systems off for 24 hours and close the sea cocks, the lack of oxygen should kill everything.


Constant exposure to bleach will shorten the life expectancy of the equipment.

[svHyLyte]

We flush and clean out the raw water cooling circuit on our Air Conditioner at least annually and often find small barnacles growing on the inside face of the glass cylinder on our Groco Raw Water Strainer. (If they are there I suspect others are growing elsewhere too, No?) To "clean" the system I recirculate a solution of Barnacle Buster and fresh water through the circuit using a Trac Ecological "Flush Cap" that temporarily replaces the standard cap on our filter. With this, after 1-2 hours of recirculating the solution, everything is gone/dissolved and I'm confident the system is thoroughly cleaned out.

FWIW...

[skipgundlach]

Originally Posted by thinwater

If you turn the systems off for 24 hours and close the sea cocks, the lack of oxygen should kill everything.


Constant exposure to bleach will shorten the life expectancy of the equipment.

Killing everything will make sure it hardens nicely, if it wasn't hard already...

Muriatic acid will get rid of it, but Barnacle Buster is much more environmentally friendly.

Ideally, you can (we can't, due to the way ours is run for the refrigeration) make a closed loop of barnacle buster in a bucket and run the pump for a while, then let it sit for a while to work, rinse, repeat (well, run again, etc.)...

[a64pilot]

I take a 5 gl bucket and put a couple of gallons of water in it , remove the inlet hose from the AC pump and connect a short hose from the bucket, then remove the outlet hose from the condenser and again place a short hose in the bucket, then once I’m sure I have circulation established with the AC pump running, I’ll add muratic acid to the bucket.
You can’t run the AC long or the water will get too hot and the AC shutdown, but you can’t leave it off too long either as if you do the gas from the hard growth being dissolved will break prime.

Barnacle buster is way overpriced for what it is.

Once finished I’ll disconnect the outlet hose and reconnect it and start the AC again adding water in the bucket until I’m sure all the acid is gone, pump the bucket dry.
I do not do this for the engine, I believe the outside of my heat ex is aluminum and I know my tube stack is heavily zinc coated. I mechanically clean it, and in my opinion pumping any kind of acid through the engine is foolish, and barnacle buster is an acid, a weaker acid, but acid.
Muratic acid is neutralized by a base and decays into salt and water, it’s not that bad for the environment, unless of course you’re the base critter.
https://sciencing.com/neutralize-mur...d-5832680.html

[Siberian Sea]

I close my seacock, drain my heat exchanger and sea strainer then fill it with engine antifreeze. Kills everything and no harm to metals. I leave it a few days then drain this into a small container to dispose of at marina so I don’t pump it into the sea. Open seacock, start engine, look for leaks and it’s good for the season.

[glcalahan]

Siberian Sea....I am assuming the antifreeze will kill any growth and barnacles but not remove the hardened barnacles.....correct???

[Siberian Sea]

No, it wont remove the harden growth but I’ve never had a problem with it. I don’t like the idea of something corrosive inside my heat exchanger. I though about a quick flush with that product you run through your cars radiator but..... then again it was just a though and didn’t want experimental ideas that something in the back of my mind says “ best not do that”.

[glcalahan]

Thank you!

I was hoping to hear there was a tablet to drop into strainer cage that would make it easy to keep growth at bay. I did use bleach tablets for 12 years on my DownEaster 38 and 7 1/2 yrs Catalina 30 but just rebuilt my Yanmar and also have a new marine AC.I don't want to damage to either.