Sail Drive recess cover

[zigracer]

My 2013 MH 40 is equipped with a Yanmar SD 50 sail drive. The sail drive protrudes through the hull through its own recess in the hull. When I took delivery of my boat, the dealer had put a hard plastic cover over this area. They told me they removed a rubber piece from the factory which they said was junk.

Prior to launch last year, I unscrewed and broke the sealant on the hard plastic piece, so that I could paint the sail drive with anti-fouling paint. I screwed it back in and sealed with 5200 or something similar. It's time to paint again and there is a little bit of growth up in there. It seems, however, that screwing the piece in and out of the hull and sealing/breaking the seal every year isn't a good idea.
What do you folks with sail drives do? Any ideas?
Thank you,

Zig

 

[Jackdaw]

The factory part was worse than that? Wow. Most saildrive installs I see have a recessed edge to allow that part to fit flush. That cover is just a flush-as-possible shroud for the actual water seal, which IS a rubber boot. Hopefully they let THAT untouched.

 

[zigracer]

Yes the rubber seal is up inside the compartment or recess. I'm told there was a rubber piece instead of this, but I've never seen what it looks like.

 

[zigracer]

Am I a pioneer here? No-one has experience with this? My plan now is to cut through the 5200 and pry the piece off, re-paint the saildrive and re-piece with silicone caulk this time. Should come off easier next year, but will hopefully stay on this season. I will see if I can engineer something better for the long term.

 

[Hello Below]

I really can't help Zig, but I will make comment and have a question.

I have a Yanmar 3YM30 married to a ZF(Hurth) SD 10 saildrive in my 2012 Hunter e33. The boat/saildrive came with a rubber fairing skirt (or boot), that I assume would be similar to what your dealer removed from your MH40. We have over 600 hrs on the engine and leave the boat in the water year around and to date, have only one problem with it. It seems sea critters love rubber, at least in these waters. So when I haul the boat annually to change the saildrive oil, I clean them off and recoat the boot with Interlux Tri Lux. I am having a heck of a time finding an anti-fouling paint that is friendly to aluminum but will adhere to rubber for more than a stand easy. This year after a couple coats of the Tri Lux, I added a coat of zinc cream which probably is a poor substitute for LanoCote Foul Release.

My question to you is why the concern about sea life above the hard plastic cover? Physical and hydrodynamicalI don't see a problem. Out of sight, out of mind. I have read many posts regarding the quality of the Yanmar and Volvo saildrive boots (It seems the ZF part is a little more robust). Here is just one link with their solution: http://svocelot.com/Cruise_Info/Equipment/SailDrives.htm

 

[zigracer]

Your comment makes sense. My plastic cover is actually a piece of 1/8 inch thick or so fiberglass. I need to source out a new piece as I've damaged this one pretty good. I've been able to put regular bottom paint on it because it is fiberglass and doesn't actually touch the saildrive. Maybe I'll try and get a couple of more years out of this and not bother with the growth up inside like you suggest. I'm going to use silicone sealant this time instead of 4200 to affix it. Hopefully it will hold. I'll trace this one and make a template for when I find new material.

 

[Hello Below]

I'm going to use silicone sealant this time

It would take a lot . . . A whole lot of convincing for me to use silicone in an application such as your's. Too darn hard to clean off down the road. And nothing else will adhere to it. 3M 4200 should at least be considered. Heat, razor blade and/or acetone will make short order of it if and when it needs to be removed.

 

[zigracer]

I used 4200 and it was a bear to get off. I decided to try Life Caulk as I think that is what Mystic Shipyard used the first time - I'm not sure, though. Haven't done it yet, so keep the suggestions coming.

 

[uncledom]

I used 4200 and it was a bear to get off. I decided to try Life Caulk as I think that is what Mystic Shipyard used the first time - I'm not sure, though. Haven't done it yet, so keep the suggestions coming.

There's a chemical called Debond that you can purchase in a small spray can. Expensive but it works.

 

[Ted]

I have a Volvo saildrive in my boat. The rubber fairing membrane is affixed to the hull with 4200. It's a pretty flimsy part. I actually like your fairing plate better than the original one except for a few points.
1. It would be better if the installation of the fiberglass panels were recessed into to hull so that it was flush with the bottom of the hull.
2. It appears that there is a gap between your drive leg and the fiberglass fairing panel. That's a good thing because the drive leg will move around and if there wasn't some clearance, it would bang against the plate. It might be a good idea to fabricate a plate with a flexible rubber filler mounted to the upper side of the panel which would retard or prevent hard growth yet allow the drive leg to move unrestricted.
3. Because your fairing plate is screwed to the hull, I don't think you need to use any sealant. This is not intended to be a water tight seal.
Here is a photo of the fairing membrane on a Volvo saildrive.

 

[zigracer]

Thanks. I am probably going to re-use the piece I have, use 4200 after I clean the boat off with Debond. I may only remove the piece every two or three years and/or engineer something I can remove and reattach easily. I will keep you all posted.

Zig

 

[zigracer]

I've posted a bit on this before. Hunter has replaced the rubber skirt around the saildrive with what is shown in the pic on the original post- a fiberglass plate. Granted it is sturdier than the rubber, however there is a 1/4 inch gap between the plate and the saildrive. Unfortunately an entire colony of mussels took up residence inside there, grew and multiplied. Anyone have any ideas on how to close the gap? I don't think it is a good idea to remove and reinstall this plate every year. What say you?

Zig