Old Air Conds !!!

[Ed Tanzer]

On JJFLYGIRL, a 1975, 53 MY; we have 4 AC units......we recently replaced 2 of the units. The 16 K BTU at the helm, and the 10K BTU in the master berth. So far, so good...the other day the units started to shut down; first thing I did was look outside at the water flow.......it was a very low flow rate. Did the usual cleaning of the strainer, was really not too bad.....had the AC guy come by and we decided the pump was fine, but the hoses and older systems was clogged up. He suggested an acid flush...this cleaned out the systems and the flow rate was restored....
Next morning I noticed water in the bilge, and after searching for the source found a pin hole in the 4 port water manifold....no doubt, due to age and the acid, the hole developed. Then 2 nights later, the original 10K BTU unit in the mid stateroom, stopped cooling....upon checking this out, guess what poured out of the freon fitting? Yes, sea water...Again age and the acid did it in....so, time to replace this unit soon.....Oh, and we made a manifold from PVC as seen below, which saved several
hundred $$$$..
Would I recommend an acid flush again? Don't think so.......


View attachment 13564View attachment 13564





Just as info
Capt ed jjflygirl
lighthouse point

 

[SKYCHENEY]

What did you use for the acid flush? What kind of acid? Concentration?

I do this periodically with a 25/75 mix of phosphoric acid and have never had any problem. I don't think I would use anything stronger though.

 

[Angela]

I've heard of this from several people where an AC tech came out and acid-cleaned old condensing units. One in particular, my friend who was selling her 80' MY, was having this done just before the closing on the boat, and after survey. Every unit holed and she got the pleasure of getting to replace every AC unit on board.

I'm with Sky - I like to use the phosphoric acid mixture instead of the heavy duty muriatic acid that the AC folks use. I understand they use that because it's faster, yet the joke is often on the owner. I can set up my bucket of phosphoric mix and let it run all day because I'm not charging myself $100/hour to sit there and wait for it to finish. I have one 33 year old condensing unit still on the boat and she's still running fine, with the occasional amnesia episodes (forgets to come back on sometimes, but when I nudge her, she wakes up). I'm gentle with her, though, and she never sees muriatic acid.