Keel Bolt Backing Plates

[Rhendy30]

I would like to do this with my Catalina 30 BEFORE I experience any problems...

I have a little hint of a smile but no water incursion yet. Having just bought the boat this season, I found the keel bolts to be at 20 ft/lbs. No wonder a smile has begun. Before I crank down on the bolts, however, I want something to torque against.

So here is my question. The nuts, bolts and washers are all stainless (and are in excellent condition, btw). I do not want to set up any galvanic action in my keel. Can I afford stainless backing plates that big? What other alternatives do I have?

Thanks!

 

[Rhendy30]

I found a place online that sells stainless steel plate. I ordered 4 pieces, custom sized for the forward 7 bolts. It is 3/8" plate made of 316L stainless, which I am told is best in corrosive conditions. Cost $225 with shipping.

They won't be installed until spring, but I will post here with the fix and the results.

 

[jrowan]

Is that Starbrite material used for backing plates in that photo? Cause it doesn't look like stainless steel. If that pic is from your boat, then I don't think that Starbrite would be a bad material to use, as its cheaper, its a strong & durable material, & being synthetic has no galvanic reaction. The only thing about a heavy S.S. plate that I would be afraid of, is that it does give a bigger surface area to torque down against, but the sharp edges of S.S. perimeter could dig into the fiberglass bilge & cause stress cracking. When considering corrosion though, if bilge water seeps in around the keel bolts where the backing plates are installed, it will accelerate corrosion to the keel studs where it is deprived of oxygen & may cause worsening rusting of the studs.

 

[Rhendy30]

Hey, thanks for the response! I looked all over the web for "Starbrite". I found cleaners, colors and even tattoo ink. I have no idea what that is.
Your points about the stainless are good ones,however.
I think that whatever solution one chooses for this situation, the object, going in, is to seal the area thoroughly to keep out the H2O (from the bilge). If you are successful at that, you keep out the O2 as well. I guess I will plan to bed the plates down very solidly to avoid any issues with sharp edges. Hopefully, if the don't move, they will be okay.

 

[Kestle]

Starboard.

 

[Kestle]

HDPE - High Density PolyEthylene

http://en.wikipedia.org/wiki/High-density_polyethylene

 

[Rhendy30]

I checked it out. Neat stuff and way cheaper than SS. I would love to get a chunk to see how well it would spread the load from one of those keel nuts compared with SS plate.