You'll be amazed as you watch the calcium melt away. SO, spray, wait 5 seconds (watch the smoke), spray again. This is important- The calcium you're spraying will neutralize the acid in about 5 seconds flat. You'll know it's working because it'll create smoke while it's burning thru calcium. Work about a square foot or two at a time. Mix your acid and water in the sprayer, and pump it up. Procedure: First, pressure wash everything off you can. This and a garden hose with an on/off trigger sprayer is all you need. If you find 9%, just use it straight-Īpplication: Get a cheap $9 garden sprayer from Low Depot. This is why you need to know how strong it is in the first place. Keep it below the rub rail and dive deck and you should be ok.ĭilution- 20% acid can be diluted 4 to 1 and still work okay, but I like it a bit stronger, say 8 to 10% as an end result. It will etch anodized, and it'll darken stainless. It's safe to use on most aluminum, like your outdrive, as long as it's rinsed quickly.ĥ0 series aluminum used to make pontoon logs isn't affected.ĭON'T get it on anodized aluminum, OR stainless steel. Likewise, stuff that will clean your dirt won't much remove calcium. This is handy to know, for dilution and for your money's worth.įirst, it's only good on calcium deposits.

But- I was looking at a gallon at HD the other day, and nowhere on the label did it state the acid percentage. The other option is to just buy muriatic acid.