Cleaning raw water cooling

[Frankly]

Not sure I have ever seen the material for the Yanmar HE tubes (I am betting on a copper nickle alloy), but just don't see the advantage of messing with solutions when a mechanical cleaning is so easy (at least in the Yanmar GM series). First time I removed both end caps, after that just the front and assume what little corrosion/ fouling is polished off will just wash out. Need to pull the front cap to clean the crap out anyway, and I always like to visually inspect what I am working on.

I have been using a Volvo product to periodically flush my big Yamaha outboard cooling system. Does seem to work but a lot of mess.

[sailorboy1]

I'm surprised so many appear to be regularly having clean their heat exchangers