Originally Posted by frgeorgeh
I saw a fellow on YouTube cleaning his in place. He had a bucket of muratic acid solution and a small pump. He tied output of pump to raw water inlet. He fed water output back to bucket. Turned it on and let the contraption run about four hours.
Does that sound like a good way to rescale the heat exchanger to you more experienced folks? If so, I may give it a try myself.
It would be relatively easy to descale that way on ours. Even easier (on ours) would be to simply block off the raw water inlet (which is lower on the heat exchanger), gravity fill through the raw water outlet (higher on the HX) and let the stuff sit for 4 hours. Flush, done. Not much in the way of fittings, hoses, pump required.
This, after just flushing both of our engines, one using the pump method, one not.
Seemed to me the pump method would more useful for flushing the full system. In our case, that's sea strainer, raw water pump, fuel cooler, aftercooler, gear cooler, and heat exchanger. With the raw water pump impeller out, and with appropriate fittings and hoses, the pump method worked fine. It's more difficult to remove the impeller on the other engine, so I experimented with the fill-and-sit method, with equivalent results.