Fouled freezer water cooling tubes?

[skipgundlach]

So, my new Sea Frost air/water - cooled refrigeration is dribbling, not spouting.

I get a long handled brush and scrub the dome filter, in case it's fouled.

I take apart the filter; it's not clogged because I cleaned it yesterday. The filter body is trickling.

I open the line to the filter. Blow it out. Still trickling.

Get a mirror to see under the pump housing. Barnacles! Worse, some of them are on the intake side.

Run some wire down all the hoses to the pump, and dredge out for the entire way, some of which are also barnacle chunks. Do the same for the elbow nipple at the through-hull intake (dome filter cover outside), all the way down to the cover. More junk. Eventually it runs free.

Reconnect everything and look outside. Much better than before, but seems smaller than I remember after previous filter cleanings. This system is not yet 7 months old, but nearly all of that time has been on a mooring in Vero Beach, apparently very fecund waters. We changed from a very fine mesh 304 filter to plastic, much less fine, because the 304 was disintegrating; holes, ends ragged, etc. I was assured that because this was an impeller pump, and had the dome filter, any small trash which succeeded in passing the dome would happily flow throughout the system. Apparently barnacles are tiny until they latch and grow in this nutrient-rich.

My presumption:

If I have some barnacle growth on the output (to the pump) side of the filter, I must also have some in the cooling lines.

How do you prevent or deal with this??

L8R

Skip

[Hudson Force]

My referig/freezer is 12VDC air cooled, but I do use a water heat exchanged air conditioning system. I sometimes ream out my cooling tubes in these systems with a long surf board leash. I've cut off the ankle fastening end and push it through the coils while twisting it. I like the use of this tool as it is soft and not damaging the inside of my coils, but tough enough to remove growth and sediments. I must confess, though, that I have not had to remove mature barnacles and I don't think that the soft nylon leash would do anything in taking off the scale.

[savoir]

The way to clean the system is to hire a refrigeration technician to give the system an acid flush. Unfortunately that will not stop the problem from happening again. All I can suggest is closing the seacocks every time you get off the boat for more than a day.

My Sea Frost cycles every four hours so it is not an issue for me. I do have to clean the filter every year and fill the system with antifreeze every winter. My seacocks stay open all summer.

[skipgundlach]

Originally Posted by savoir

The way to clean the system is to hire a refrigeration technician to give the system an acid flush. Unfortunately that will not stop the problem from happening again. All I can suggest is closing the seacocks every time you get off the boat for more than a day.

My Sea Frost cycles every four hours so it is not an issue for me. I do have to clean the filter every year and fill the system with antifreeze every winter. My seacocks stay open all summer.

Our system runs more than not, and cycles when it's actually cooling, so there's rarely much time of standing water. We can't close the seacocks, either, as it's running all the time, whether or not we're there.

Our water is so foul that we have to clean the filter every 10 days or so...

How long is a surfboard leash? I have some old throttle cable I use for a fish, sometimes, as it's rigid linearly but very flexible laterally. I wonder how long it would have to be, and how much of a challenge it would be to navigate the bends...

And, as to an acid wash, is that as in muriatic acid? I could probably rig a means to suck in and distribute whatever; even just vinegar, if left long enough (meaning, I'm back to air cooling only, which is not nearly enough for our location), would dissolve them.

Thanks for the ideas...

L8R

Skip

[savoir]

Wow that really must be dirty water. I'm in the water for 5 months/year and clean the fridge raw water filter only once. I'm sure the antifreeze kills a few bugs too.

The acid is muriatic acid. It should be mixed up at 1:5 and cycled through the system for 30 mins or so. You could do it yourself if you have the gear - bucket, pump, hose connectors etc. I wound up with all kinds of black goop in the bucket when my guy did it last year so it was worthwhile for me. Zero issues since then.

[SV THIRD DAY]

Just another example of why using water cooling for a boat Refrigeration system usually leads to increased maintenance, drama and headaches just waiting to happen. Let that plug up and not notice it and Ka-Pow...compressor over heat.

[skipgundlach]

Sea Frost's response to the cleaning question:

"Barnacles will grow from seedlings in your water system. Hit it with Clorox or Barnacle buster once in a while or turn the pump off dockside to starve the critters."

Starvation won't get rid of the bodies. Clorox may kill them, but won't dissolve the shells.

Searching for BB got this, among others:

http://trac-online.com/index.php?pag...mart&Itemid=62

"Each gallon of Barnacle Buster™ in this case makes at least 5 gallons of ready to use solution, giving you a total of 20 gallons, enough to clean all the sea water systems on small boats."

Amazon sez "Product Description
Size: 1 gallon
A ready to use acid-based cleaner for the quick removal of barnacles, rust, oil stains and algae. Will not harm fiberglass or gel coat. pH 1.2 Ready to use."

So,while claiming to be environmentally friendly, it's acid-based. I wonder what acid? And I wonder if muriatic, at whatever concentration, will have any effect on the pump (shouldn't affect the hose or tube, I don't think)?

Aside from the nuisance value, carrying around all that stuff, as it appears I'll have to do that at least monthly (based on the degradation of the stream, already, since I cleaned it), isn't any fun.

Just another reason I liked (until it died) my Frigoboat keel cooler (closed) system.

[skipgundlach]

My 7-15 reply to the response from Sea Frost, above:

"I just a few minutes ago finished a clorox (straight) flush and set-5-minutes. Getting a pickup established was a bit frustrating, but the flush and subsequent fresh water flushes dislodged all manner of junk, including shell type stuff.

It occurs to me that, being copper in and out, critters likely wouldn't do very well inside the condenser water tubes, and, after a few push-and-back-off backflushes into my well to jiggle the trash which seemed to have piled up somewhere (wouldn't pump, but would free-fall backflush), it ran freely.

BB is primarily phosphoric acid; I have a gallon of the stuff ordered for when I return from my trip on the 23rd. If I don't have to do this very often, I guess it's livable, but it's a real pain in the back based on where everything is located for me to be able to do it."
***********

Given how much crud came out with just clorox, I expect that BB will completely free me up. As well, as said above, I don't really expect that critters would do well in an all-copper environment, so I am no longer worried about that.

Meanwhile, it's now about 15 hours into recommission; the second plate is =starting= frost, and the third plate is finally cool - though that may be just a matter of being in the box which is getting colder. I started at 85.3, both (empty boxes other than cold OJ and a dozen eggs), ran it on high (with the water pump running too) overnight, and were at 31.2 and 41.2 12 hours later.

I hope this is normal, and I don't have to fiddle with the Constant Pressure Valve again, as I did on the last restart. Too much and the liquid point arrives much too close to the compressor (outside the box, even). Too little and you get what I'm seeing, even after it's all at cycling temps...

L8R, y'all

[savoir]

Congratulations on getting a result.

While you're at it this is the time to check the raw water strainer. You want one with a fine mesh basket such as 50 micron. This type of thing will do the job.

[skipgundlach]

Our filter started life as a very fine 304, which had ragged edges and looked like swiss cheese in only a few months.

We went to a larger opening plastic filter, which had to be ordered from Groco. However, SF assures me that the size opening we have will be just fine on the pump, and no issue to passage.

The very fine filter, while it lasted, I don't expect did anything for barnacles in the incoming line (pre-filter) and perhaps not for the outflow hose, either, based on how much junk came out when I flushed with clorox.

Thanks for the thought, though. As to my mindset, I even have a filter on my shower pump, which is trash-rated ☺

[skipgundlach]

In another thread, another cruiser opined that where we are is the worst he's ever seen for barnacles. The local diver made the same observation, along with having to buy new gloves, and take twice as long as he used to have to take on each job.

In yet another thread, someone suggested putting chlorine tablets in the filter housing. Apparently, they make little pellets, about the size of a stack of 8 or so quarters. I have not yet installed them, but I hope they fit into the new plastic filter we have (the metal one disappeared in many places in only a few months).

I was worried about the intake (the points beyond the filter will get chlorine, of course) getting gummed up again - but realized from having done filter changes, that the cooling line, when I open the filter, will leak/drain down into that area. So, each time the system cycles, I'm hopeful a backwash of chlorine occurs; it SHOULD keep that cleaned up.

Barnacle buster on order; I'll report back when we do that. However, we've noted a very much more robust output stream since we came back from a week away, so apparently the clorox shock we gave it did a great deal of good.

And, to wrap up, now that the boxes are down to temps, the 3rd plate is nearly completely frosted. I'm hopeful that it reaches the bottom, soon, as I'd rather not muck with the constant pressure valve again.

L8R

Skip

[savoir]

Originally Posted by skipgundlach

Our filter started life as a very fine 304, which had ragged edges and looked like swiss cheese in only a few months.

We went to a larger opening plastic filter, which had to be ordered from Groco. However, SF assures me that the size opening we have will be just fine on the pump, and no issue to passage.

The very fine filter, while it lasted, I don't expect did anything for barnacles in the incoming line (pre-filter) and perhaps not for the outflow hose, either, based on how much junk came out when I flushed with clorox.

Thanks for the thought, though. As to my mindset, I even have a filter on my shower pump, which is trash-rated ☺

There is nothing trashy about showering on the boat.



As for the filters, mine is the 50 grade Jabsco one and looks like new after 3 months daily use. Just to be sure I checked it today and all it needed was a rinse.