Rust on the outside of my Keel

[bowman316]

I have a 1970 Grampain 26 Ft sail boat. It has a fixed keel, which is made out of lead, or cast iron. not sure. If I remove the floor board in the Galley, you can see huge bolts with nuts on them, coming up from the bottom of the keel.
Now I assume the whole keel is wrapped in fiberglass, but the fiberglass near the bottom of the keel is covered in rust.

There are hundreds of tiny bubbles of rust on the outside of the keel, they were really easy to sand off thou. But how does fiberglass rust? Is this something to worry about, or should i just let the thing rust?

Does anyone know how the keel is held onto the boat? Is the fiberglass wrapped around it, the only thing holding it to the boat? Or is there some system at the top of the keel, that will hold it onto the boat? Where do those bolts go, on the top of my keel? were they only there to mold the lead, when it was made?

 

[FastFission]

Re: Rust on the outside of my Keel

I found a website for the Grampian 26 and it looks like you probably have an iron keel. The bolts are probably studs that are threaded into the cast iron keel. Those are your "keel bolts" and they are what holds the keel onto the hull.

You may have fiberglass all around the keel, or you may just have paint on the keel. Based on the rust bubbles, I'd be surprised if there's fiberglass on the keel (although it should have been pretty obvious as you were grinding. On my old Columbia, the keel was just a solid hunk of cast iron bolted to the hull. The rust bubbles are pretty typical, we were always pretty cheap and we just ground the rust out and threw some filler in the pits and repainted over it.

The website below has a bunch of information on your boat. They do look like a sweet little craft.

http://www.grampianowners.com/G26/grampian_26.html

Happy sailing.

 

[bowman316]

Re: Rust on the outside of my Keel

so is there ever an issue of water getting in where the fiberglass stops, and the keel starts? I really don't see much of a dividing line, like I don't see a lip, where the fiberglass stops, and exposes the keel to the water the rest of the way down.

When I was sanding the keel, It felt more like fiberglass. But its so old and rusty, its hard to tell. I just don't see a spot, where there could be a transition from fiberglass to the keel being exposed.

 

[bowman316]

Re: Rust on the outside of my Keel

I was also wondering about sacrafical anodes. Has anyone mounted one on their keel? Would you put it on the inside, or the outside, where it will be exposed to the water?

 

[smallboatlover]

Re: Rust on the outside of my Keel

i think your supose to have anodes on your keel just for that reason

 

[bowman316]

Re: Rust on the outside of my Keel

I'm gonna JB weld an anode onto the outside of the Keel, that should work, right?

 

[FastFission]

Re: Rust on the outside of my Keel

I've never seen anodes on a keel. Doesn't mean it's a bad idea, but I just don't know. We never got an issue with water getting in above the keel, but I can't say that it's impossible. We did keep that area painted pretty well. I suppose that yours might be faired with something, or perhaps they did use a fiberglass coating.

When we sanded the cast iron, I did notice that some of the spots seem real soft, almost like lead. I suspect that was either previously filled with something, or perhaps the corrosion makes little spongy areas.

You might try the Grampion forum. They'd probably know more about your boat.

 

[bowman316]

Re: Rust on the outside of my Keel

is a wet rudder a big deal?
I have had water seeping out from the inside of my rudder for a few years now.
i think it is getting in where the post comes down from above.

 

[SolingSailor]

Re: Rust on the outside of my Keel

Here is a topic I have a lot of experience with, as I have tried several solutions to the problem of a rusting iron keel.

First, let me say that keels don't get anodes, because they are not supposed to be exposed to the water. And gluing an anode on wouldn't work anyway, as there has to be electrical conductivity.

OK, now for the keel. The easiest and least effective method is to grind down to bare metal, then use a wire brush on the grinder to get some of the rust pockets out. This method, plus the coating described below works for a couple of years.
The only permanent solution is to sandblast the keel to shiny metal, then immediately coat the keel with epoxy. Coat within an hour or two, or the rust will start right up again. Then fill the pits with epoxy filler, then coat the entire keel with about 6 coats of epoxy barrier. I did this to my iron keel almost 20 years ago, and it's still good. This method is a lot of work, and requires that you really love your boat.

Of course you might just slap some paint on, but guaranteed it will rust through in no time. There's just no way around this very labor intensive job.

 

[bowman316]

Re: Rust on the outside of my Keel

what about a rudder that has water leaking out of it?
I'm gonna seal up the top, where the water is getting in, with calk.

But I don't think the water inside there will really hurt anything.
the rudder has a stainless steel rod going into it, with smaller steel ribs inside it. And its filled with resin inside.

 

[bowman316]

Re: Rust on the outside of my Keel

well now my keel bolts are leaking. water is slowly seeping into the aft 2 or 3 bolts.

 

[bcbit01]

Re: Rust on the outside of my Keel

OK. We've figured out you have an iron keel with no fiberglass or resin/putty jacket right? And you have also figured out that your keel joint leaks. There is no way for water too "seep out" of a solid iron keel so lakewater/seawater is leaking into the bilge through the hull/keel joint. The bottom of the interior of your boat is a structural grid bonded into the hull. It is this structure that the keel hangs from on those stainless steel bolts....they pass through the hull so the joint between the top of the keel and the bottom of the hull needs to be watertight right? They make bedding compound (really epoxy filler) for exactly that purpose. To fix this right, haul the boat. With her in the slings and off the ground, loosen your keel bolts inside the bilge to gradually lower the keel off the hull. This sometimes takes a bit of coaxing. Continue until you have enough space to comfortably and safely clean the old bedding compound off both the hull and the keel. Apply new bedding compound (NOT caulk or silicone or polyester fairing putty or anything else! Bedding compound or epoxy filler (like Interlux Watertite). Butter both surfaces liberally (so you are confident compound will squeeze out ALL around the joint) and then evenly tighten the nuts inside until the keel snugs back up to the hull. Torque to factory specs. Now that your keel is properly bedded, use your finger to smooth the excess compound into a fillet to smooth the transition from hull to keel. You can set her down on the trailer or cradle or jack stands now. While you're waiting for the bedding compound to cure, this is a fine time to" treat your keel with some love" as suggested by Soling Sailor in post #9. Grind away any pitting or rust pockets keeping an eye on maintaining a decently fair surface. When you have it as smooth as you can get it and removing any more "visible" rust will require digging up the keel, sandblast the rest of the spots. Now chemically treat the whole keel with metal prep to eradicate the "invisible" rust. They sell this product in autobody supply stores. Immediately apply your first coat of epoxy resin to keep new rust from forming...I've seen rust re-form on treared steel within minutes. Now you have a choice: fair the keel and then epoxy barrier coat the keel or apply a single layer fiberglass jacket around the keel so you never have to do this again. Finish off with the anti-fouling of your choice and splash her back in the water. Voila...no more leaks and no more unsightly rusty keel.