Growth below my starboard rub-rail a continuous problem

[MichaelStacy]

Anyone find a 'cure' for this growth? We wash and scrub it away only to find it back in a few weeks. Would sealing around the rub-rail (top & bottom) help resolve this. This side faces south, the sun side. Boat is in Santa Barbara, CA
Thank you..

 

[jssailem]

If you were up here in the PacificNW I’d say it was moss or algae. Happens in the shade.
You say the area is facing the sun. Is the area shaded by a big boat next to you?

Not sure sealing would help. Soap and water would be my first choice.

It doesn’t happen on the North facing side of your boat?

 

[MichaelStacy]

I am sure it is moss (it is green). I just wonder if i need to allow rub-rail to dry, then seal top & bottom to keep moisture out.
Yes - ironically it is on the south side. It is probably somewhat shaded by the boat next to me.
Thank you for reply..

 

[jssailem]

There really is no way to “seal” the rubrail. If you try, because the rail is designed to move/flex (somewhere) along the length the seal will break. Then you will get trapped water beneath the rail. That would be worse.

The challenge is using chemicals (beyond soap and water) could affect your rubrail (a vinyl), the gelcoat, or the metal on your boat. Be careful the path you take.

 

[kloudie1]

I agree, don't try to seal it.. Looks like water is being trapped behind the rail and it slowly weeps out, feeding the moss. Ya might try getting some weed killer and spritz the upper gap to get it into the space behind the rub rail... Then caulk the top, leaving the bottom open to drain the space. Don't get the kind that says "won't kill grass..." Get the real stuff ..

 

[MichaelStacy]

Thank you - That makes a lot of sense!!

 

[rgranger]

Don't get the kind that says "won't kill grass..." Get the real stuff ..

Like diesel!

 

[MichaelStacy]

LOL - thank you

 

[jaysweet]

I have a 2004 H306, and I've had the rubrail off all the way 'round in 2020 (aft part) and 2022 (fwd part). We have exactly the same rubrail, so first of all, let me comment on what it is. See Rub Rail Adventure . I think these rubrails have some positive points, and some negative. On the one hand, they're very solid, and do a good job of protecting the hull from pilings and docking misadventures. But to say they were "designed" to do anything other than this is an overstatement. They were "designed" to be easy to install, and to protect the hull/deck joint, but the actual implementation is pretty lacking. The rail looks like a capital G in cross-section, but with a hook on both ends of the curved part. This sort of "snaps" over the hull/deck joint, and then large stainless screws are driven through the rubrail and (hopefully, most of the time) actually into the 4200 or 5200 compound sealing the joint. This ends up rather compromising the joint, especially if you ever actually use the rubrail by ... you know... running into anything, even mildly. This causes leaks in the joint as the large screws are driven further into the joint. Or that's my theory.

Anyway, this large G-cross-section heavy vinyl rubrail has lots of space inside the G after it has fit over the joint. This space gathers crud (dirt, bird poo, more crud) that seeps into the space between the hull and the top of the G. It sits in there and festers. I've considered caulking the top seam (between the top of the rubrail and the hull / toe rail), but I suspect it would just look like crap, and would probably come loose rather soon. There's no way I'd caulk the bottom of the rubrail, as this is where water gets out after it invariably seeps in there.

You could pull them off, but I won't kid you: it's a rather big job. I only did it to try to fix leaks into the cabin. I think the leaks are better after I pulled the rail off and caulked, but it's still not perfect. If I were you, I'd probably just clean under the rubrail every now and then with a scrub brush and some soap and water. If you don't have water leaks from the rail into the cabin, just cleaning it is _way_ easier than taking the rail off and cleaning out the crud, which will come back, in any case.

 

[MichaelStacy]

I have a 2004 H306, and I've had the rubrail off all the way 'round in 2020 (aft part) and 2022 (fwd part). We have exactly the same rubrail, so first of all, let me comment on what it is. See Rub Rail Adventure . I think these rubrails have some positive points, and some negative. On the one hand, they're very solid, and do a good job of protecting the hull from pilings and docking misadventures. But to say they were "designed" to do anything other than this is an overstatement. They were "designed" to be easy to install, and to protect the hull/deck joint, but the actual implementation is pretty lacking. The rail looks like a capital G in cross-section, but with a hook on both ends of the curved part. This sort of "snaps" over the hull/deck joint, and then large stainless screws are driven through the rubrail and (hopefully, most of the time) actually into the 4200 or 5200 compound sealing the joint. This ends up rather compromising the joint, especially if you ever actually use the rubrail by ... you know... running into anything, even mildly. This causes leaks in the joint as the large screws are driven further into the joint. Or that's my theory.

Anyway, this large G-cross-section heavy vinyl rubrail has lots of space inside the G after it has fit over the joint. This space gathers crud (dirt, bird poo, more crud) that seeps into the space between the hull and the top of the G. It sits in there and festers. I've considered caulking the top seam (between the top of the rubrail and the hull / toe rail), but I suspect it would just look like crap, and would probably come loose rather soon. There's no way I'd caulk the bottom of the rubrail, as this is where water gets out after it invariably seeps in there.

You could pull them off, but I won't kid you: it's a rather big job. I only did it to try to fix leaks into the cabin. I think the leaks are better after I pulled the rail off and caulked, but it's still not perfect. If I were you, I'd probably just clean under the rubrail every now and then with a scrub brush and some soap and water. If you don't have water leaks from the rail into the cabin, just cleaning it is _way_ easier than taking the rail off and cleaning out the crud, which will come back, in any case.

Thank you Jay - alot to consider. And, Happy Thanksgiving
Michael

 

[Crazy Dave Condon]

Hunter used 5200 in the hull to deck joint. If ever pulling the insert out, mark with a pencil ever three feet the insert so you are putting it back into the base correctly

 

[danooxnard]

I had the same problem on my C22 in Oxnard. I pressure washed the rub rail between the aluminum and fiber glass. Got tons of moss dirt etc. out of the crack. I then put clear silicone on the top of the rub rail leaving the bottom open. I used a rubber caulking tool to push the the silicone into the crack and remove excess silicone. It has remained clean for several years now. Dano

 

[MichaelStacy]

I had the same problem on my C22 in Oxnard. I pressure washed the rub rail between the aluminum and fiber glass. Got tons of moss dirt etc. out of the crack. I then put clear silicone on the top of the rub rail leaving the bottom open. I used a rubber caulking tool to push the the silicone into the crack and remove excess silicone. It has remained clean for several years now. Dano

Thank you Dano. Nice description of your fix