Jim, Before I was introduced to Barnacle Buster I used diluted muriatic acid for cleaning out an air conditioning system. That was close to 20 years ago and I do not remember the dilution I used, but my best guess is about 20%. It worked very well, but I circulated it in a loop (recirculation) rather than punping it in and letting it sit--it gets the job done faster and removes growth more quickly that at. As you no doubt know, muriatic acid is very nasty, caustic stuff and needs to be dealt with carefully--rubber gloves, eye and skin protection. There's not much room for error. I've been using Barnacle Buster for the raw water side of my engines and generators, recirculating it for about two hours, and it does an amazing job. Milt Baker, Nordhavn 47 Bluewater jimfelds@focustarcapital.com wrote: Can't get BB here and want to descale (kill barnacles and other marine life) inside my air con system. The MSDS from BB says the goop is 10 percent phosphoric acid. Phosphoric acid is made from sulfuric acid plus some gypsum. Could I use a 10 percent muriatic acid solution instead? BB says leave it in for 6 hrs. How long would I leave the muriatic acid solution? Any ideas are welcome. Thanks.

An interesting aside to the subject of using Muriatic Acid, when opened or left uncovered in an enclosed area, all bare, exposed steel will become coated with superficial layer of rust. Not particularly damaging, unless left for a long period of time.. *Rudy & Jill Sechez * *BRINEY BUG-a 34' Sail-Assisted Trawler * *Anchoring Consultants-trawlertrainingabc.com* *850-832-7748 * *Beaufort SC northbound- Chesapeake* > >