Gray Deposits on Lower Unit

[alancs68]

I have a Chaparral 230 with a 5.7 Merc / Bravo 3. Upon pulling the boat out of the water, the lower unit was covered with a thin layer of grayish colored scale. What is this? I have tried removing it with Lime Away and CLR, and they won't touch it. Neither will any of the hull cleaners. I can get it off with a scotch brite pad, but this scratches the paint on the outdrive. There is some minor corrosion I need to sand and paint, and need to remove this to touch up the lower unit.

Any suggestions would be appreciated. Thanks.

 

[JustJason]

Re: Gray Deposits on Lower Unit

Get used to scratching the paint. Its nothing a little rustoleum won't take care of anyways. And forget about household cleaners when it comes to boats, your going to need some more serious stuff if you want to keep things clean. I have sprays in my garage that range from mild degreasers to fuming hydrocloric acid. Get yourself a pressure washer if you want to keep your hull and drive clean. I have a Karcher with a honda motor that I bought years ago and it works great. You'd be surprised what other uses you find for it once you have one

Welcome to iboats

 

[Lodgepole]

Re: Gray Deposits on Lower Unit

Lime Away used to fizz up on my Mercruiser drive back in 1980 and clean the scum and scale right off. Now it is crap and won't cut much of anything. I guess that is what our government has done for us. As for CLR, I never c ould get it to do anything that water wouldn't do.

 

[Bondo]

Re: Gray Deposits on Lower Unit

Ayuh,... You buy the Real stuff at Hy-Vac shops....
Ask for the stuff they use to clean copper heating coils...
With the dilution rates, a gallon goes a Long ways...

 

[porker99]

Re: Gray Deposits on Lower Unit

I hate to say it but u need a lower unit shower. those brava 3 get very hot whats happing is that the oil inside the lower unit is hot and boiling the water and making the grays ****. The are easy to instal cost around 200 but well worth lowers heat about 50-100 deg.