Boat Hacks – Marine Growth Edition – An Update

It’s been three months since I placed the copper fittings in the air conditioning seawater strainer as described in Boat Hacks – Marine Growth Edition, and it’s time for an update. I’ve cleaned the strainer about three or four times since starting this experiment, and while the addition of copper hasn’t done a thing for the slime and soft growth that forms (nor did I expect it to), I haven’t found a single barnacle forming inside the strainer body since that time. Usually there would be a half dozen or so that I’d have to chip out at each cleaning.

I used my digital caliper to compare a new fitting to one that’s been inside the strainer for the last 90 days, and I found that the used one was uniformly thinner by about a thousandth of an inch.


This tells me that copper is definitely dissolving into the seawater as it flows through the system. So with no apparent downside, a very low cost to implement, and good results so far, I’m going to call this hack a success!

2 thoughts on “Boat Hacks – Marine Growth Edition – An Update

  1. Robert Gallagher

    ok Robert…I have been following and was excited about the results of the copper experiment. I have a stainless strainer. Can I use a couple of copper couplings or will I have issues.

    1. Robert Post author

      Well, I’m no expert, but when I look at the nobility table, I see that copper is much higher than stainless, so it should be OK. I say give it a try for a month and see what happens. Besides, I’d guess your stainless steel strainer sits in a bronze housing, which means it’s already in contact with dissimilar metals with no adverse effect.


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