jimbaerselman
Well-Known Member
The deposit is mainly carbonates, with some phosphates and borates, tiny quantities of silicates and lotsof other lovely compound jobs, dolomites etc. Their metals are mainly calcium and some magnesium.
The deposits are, in fact, all the least soluble salts which have been dissolved out of upper rocks by water and dilute carbonic acid, washed into the sea, and in the Mediterranean, concentrated by evaporation.
You'll note in the pretty picture above that one pipe is much more gummed up than the other. The more clear pipe is the inlet to the antisiphon vent fitting. In normal use, this remains full of water - and any acids sent round to clean the system. The thickly gummed up pipe was the outlet connection to the fitting. Acids, water, etc could not stay in contact with this end. They just trickled away and left a wet surface, which evaporated, building the deposits up.
Bashing or acids? I re-routed piping where necessary to make its removal easy, since I didn't believe that acids would deal with the thicker deposits. It took about 250cc 15% dilute HCl about 10 minutes to fizz clean just the anti syphon loop. A crude calculation showed me that I'd need at least 8 litres to do the rest of that pipe - that's if I could keep the acid in contact.
So I'm very practiced at spraying all around me on the marina with heads crud . . .
The deposits are, in fact, all the least soluble salts which have been dissolved out of upper rocks by water and dilute carbonic acid, washed into the sea, and in the Mediterranean, concentrated by evaporation.
You'll note in the pretty picture above that one pipe is much more gummed up than the other. The more clear pipe is the inlet to the antisiphon vent fitting. In normal use, this remains full of water - and any acids sent round to clean the system. The thickly gummed up pipe was the outlet connection to the fitting. Acids, water, etc could not stay in contact with this end. They just trickled away and left a wet surface, which evaporated, building the deposits up.
Bashing or acids? I re-routed piping where necessary to make its removal easy, since I didn't believe that acids would deal with the thicker deposits. It took about 250cc 15% dilute HCl about 10 minutes to fizz clean just the anti syphon loop. A crude calculation showed me that I'd need at least 8 litres to do the rest of that pipe - that's if I could keep the acid in contact.
So I'm very practiced at spraying all around me on the marina with heads crud . . .
