Cleaning A/C Unit

[Exodus]

Hello all. We have purchased a boat that wasn't used for a little while. A gentleman was talking on the dock one day that he uses chlorine tablets in his strainer. At first, I thought this to be a good idea. Then I was concerned that it may wear down some internal parts as well as some rubber gaskets and such. I was hoping I may have some of your ideas. Thanks

[pascavone]

chlorine and steel tubes are not a good combinations.

your compressor coiling coil is rejecting 120 degree heat into the sea water, so their is little chance anything is going to live and grow in the piping.

It is not broken, don't fix it.

But, if you want to clean something, stick your head under the hatch with your flash light and you will see a micro filter velco to the face of your evaporator.

you should take it off and clean it.

if its 10 years, old it will fall apart, but a new one at home depot is 97 cents....

[Exodus]

Thanks for the idea. I will have to do that.

I must apologize, I took the easy way out and asked a question instead of easliy doing the research for myself. Although I did not know there was stainless steel pipes going through there (duh). If anyone is curious why this is a bad idea, here is the reason:

Corrosion resistance of stainless steels
Chlorine in contact with water and as a dissolved gas, sometimes found in water treatment applications, is potentially aggressive to stainless steels.
Localised crevice & pitting corrosion attack is a hazard in water and stress corrosion cracking (SCC) can be an additional hazard in damp chlorine gas, if the temperature is high enough.
Condensates formed over chlorinated water in storage tanks have been known to result in staining or pitting to stainless steels. Improvements to ventilation in such situations should help reduce the risk of attack.

Chlorine as a sterlizing or sanitising agent
When using chlorine as a sterilizer or sanitiser in contact with 316 type stainless steel items, a maximum of 15-20 ppm (mg/lt) 'free' chlorine is suggested, for maximum times of 24 hours, followed by a thorough chlorine free water flush.
As with any additions, thorough dilution around the injection point is important to avoid localised 'over-concentration' problems.

Residual chlorine levels in waters of 2ppm maximum for 304 and 5ppm for 316 types should not normally be considered a crevice corrosion hazard.

Chlorine dioxide as a sanitiser in contact with stainless steels.
Chlorine dioxide (ClO2), occurs naturally as a gas, but is normally dissolved in water, as the gas is highly explosive.
Although a powerful oxidiser, unlike chlorine it does not breakdown to release chlorides. The chlorine and oxygen work together tending to form chlorites in the oxidation process. Although the chlorite can break down to form chlorides, it is a weaker oxidising agent than the chlorine dioxide and so can be expected to be less of a hazard to stainless steels when used as a water sanitiser.

Source data can be found at Outokumpu Corrosion Handbook - chlorine and chlorine dioxide.

Not even thinking about the HCL (hydrochloric acid) component. Which in my professional opinion, is the second deadliest acid (HF being worst). Would be a horrible idea.

Although I think some bad stuff could survive at 120 degrees, I certainly get the point.

Again, thanks for getting back to me! I appreciate it more than you know.