26 The Eastwood instructions called for 3 ounces of muriatic acid to be mixed with 60 ounces of water to make a 1/2 gallon of 20:1 solution. I measured out 3 fluid ounces in a glass before mixing them. The glass was then disposed of. You don't want this going back in the kitchen cabinet! Note the use of chemical-resistant gloves. Muriatic acid is made up of about 32 percent hydrochloric acid and requires correct handling and disposal. Again, the solution was sloshed around in the tank for 10 minutes to ensure total corrosion removal, leaving the filler cap hole open to allow pressure to escape.