Cleaning the Bottom

[Tony Carlisle]

I've had my Catalina 22 for about eight months. I had her bottom painted with two coats of red Bottom Shield immediately after I bought her. I keep her in a slip in a fresh water lake. I noticed growth on the rudder last month and used a long-handled brush to scrub the growth from the rudder. When I scrubbed the growth from the rudder, I noticed what looked like red paint staining the water as I moved the plastic-bristled brush back and forth. There were not flakes of red paint floating in the water, but rather the water just began to take on a reddish tint as if someone had put red food coloring in the water. I see the same reddish tint when I scrape the bottom with the long-handled brush.Is this color tint in the water a normal side-effect of scrubbing the bottom of the boat? Am I removing the bottom paint in addition to growth when I scrub the bottom? Do I need a brush with a softer bristle?

 

[Randy]

Probably OK

I don't have experience for that exact paint but my bottom paint does a similar thing. These are anti-fouling paints which are intended to kill marine growth. To be effective they continuously wear away which exposes new herbicides in the paint. So my sense is that what you are experiencing is normal.

 

[Bayard Gross]

Anti-fouling paint will come off when scrubbed

As just about any salt water sailor who moors his boat in salt water will tell you when they nearly weekly scrub the bottom of their boats, yes, some of the anti-fouling paint does dissipate into the water.What surprises me is that I thought Bottom Sheild, I presume West Marine's, is a modified epoxy and as such a "hard" paint which should be less suspectible to wearing away when scrubbed. Abalative paints will more easily wear away when scrubbed, and that is a significant advantage to avoiding paint build up.Nevertheless, I use a very stiff brush which works much more efficiently than a soft brush. I brace the handle of my brush along the top of the gunnel of my dinghy to give it upward push against the bottom of the hull on my C-22.I also ship my rudder when finished sailing which means I need not put anti-fouling paint onto the rudder, just a hard enamel paint over an epoxy base which makes for a very slick rudder. Also, this preserves the pintles and gungeons by avoiding that slight back and forth movement when at the mooring and keeps the rudder dry to prevent water damage.I do not think you require two coats for fresh water. And again because I do not think Bottom Sheild is an ablative, you may have to repaint the bottom again in the spring. And then you start to get that awful modified epoxy paint build up. So, in the spring, try using just one coat of an ablative anti-fouling paint.

 

[Tony Carlisle]

Thanks Bayard and Randy

Gentlemen: Thanks for the responses. Now that I'm secure in the knowledge that I'm not inadvertently destroying my boats bottom paint protective coat, I'll continue to scrub away!