Fixing the Keel...

sapster77 · #1 (**permalink**) 11-01-2010

Hi,

In an attempt seal the gap between the hull and the keel, the previous owner has used a flexing, black material (could be sika or 3M 5200) and he has used A LOT! It is not only in the tight hull/keel gap but several centimeters up along the hull and down the keel (pictures to follow). Problem is that the material is detaching in a few places and I am a little unsure on how to proceed. The seal is still working (i.e. no water in the bilge), but is does not look especially nice - not really faired properly. It is painful to the eye:-)

Currently i'm considering the following:

Option 1: The lazy approach. Cut of the lose bits with a knife and refill with 3M 5200. Hmmm. Still gonna look bad...

Option 2: Cut it all off, sand it down, refill the gap with epoxyflex (west marine), apply a 10cm wide strip of fibreglass with epoxyflex over the gap. Fair it. Then 2 component epoxy, primer and bottompaint.

Option 3: Keel off? Nope - that was done 2 years ago and all this black stuff i'm fighting now, is the material that oozed out when the keel was put on.

Any advice will be greatly appreciated!

Thank you for your answers and help:-)

Peter

sailingdog · #2 (**permalink**) 11-01-2010

First, it would really help if you said what kind of boat you were doing the work on. Some boats, like older Catalinas, often had this kind of repair done as a cosmetic fix to a more serious underlying problem—in the case of the Catalinas it was a plywood keel stub support rotting and allowing the keel to sag, causing the Catalina smile.

The reason the material is detaching is likely improper surface preparation. I would recommend using a razor to cut as much of the sealant off as possible, without damaging the sealant in the hull-keel joint itself. Then you could fair the area with fiberglass and thickened epoxy. I would go with 15 cm or 6" wide fiberglass tape rather than the 4" stuff, or over lap the 4" to cover a band 6-7" wide. You shouldn't need a primer between the epoxy/fiberglass and the bottom paint.

Photos would help.

Bene505 · #3 (**permalink**) 11-01-2010

Making a few guesses here... Does it flex a bit when you push on it with your thumb? If it's flexible material then it could be Sikaflex or another material designed to flex when the keel expands/contracts at a different rate than the hull due to changes in temperature.

If so, don't interfere with it, it's a pain to re-apply. Instead, get a dremmel pencil-like tool and fair it by hand by removing excess material. But don't go too close. New sikaflex won't stick to old sikaflex, so you'll end up having to strip it all the way around the keel and re-applying -- sort of like making a new O-ring around the hull-keel joint. Otherwise there will be a crack when the old and new meet which will allow water in. Then after you've made this new o-ring of sikaflex, you'll be right back where you are now, looking to fair the excess. (The stuff is hard to work with, it will look really slpoyy after you re-apply it. No surprise it looks like it does now.)

If you do cover with a hard epoxy, it may crack over the winter when the frigid temperatures makes the metal in the keel contract in size.

Like I said, some guesses in here...

Regards,
Brad

Regards,
Brad

CharlieCobra · #4 (**permalink**) 11-01-2010

If it's 4200, just trim it up and leave it be. I used 4200 on a keel we did this Summer but kept on top of the cleanup and trim after we reset the boat on the keel. Once it was done, all ya had was a nice black line which disappeared with bottom paint.

olson34 · #5 (**permalink**) 11-01-2010

Dear Mr/Ms Sapster,
I suggest that you "uncloak" a little bit and put your boat model and year into your empty bio here.
Also enter your geographic sailing area.
That little bit of information will not assist anyone in stealing your nautical ID, and helps a lot to establish rapport with the other sailors here that might like to assist you.

Fair Winds and moderate seas...

LB

sapster77 · #6 (**permalink**) 11-01-2010

Quote:

Originally Posted by olson34

Dear Mr/Ms Sapster,
I suggest that you "uncloak" a little bit and put your boat model and year into your empty bio here.
Also enter your geographic sailing area.
That little bit of information will not assist anyone in stealing your nautical ID, and helps a lot to establish rapport with the other sailors here that might like to assist you.

Fair Winds and moderate seas...

LB

My apologies - I was not trying to cloak

. Profile is now updated

Thanks for all your answers. I want it to look like the one you did on the picture charliecobra - that looks nice. But as you will see on the picture when I upload it tomorrow there is a long way to go.
The material is flexible to the touch, but I am not sure how to determine whether it's 4200 or 5200?
Sailingdog: The boat is a Bavaria 32 from 2005 with a steel fin keel. I see your point in using a wider strip of fibreglass. Would you use one of the rather new "flexible" epoxys?

Thanks again.

sapster77 · #7 (**permalink**) 11-03-2010

I am desperately trying to upload some pictures of the keel, but it keeps saying "upload failed". Does anyone know how to upload pictures? The are .jpg, less than 97KB and less than 800x600...

tommays · #8 (**permalink**) 11-03-2010

You have to use a photo hosting sight like Photobucket or Picassa and then post them here

sapster77 · #9 (**permalink**) 11-03-2010

Hi again,

Aaah ok - pictures can be found here. Thanks!

MobileMe Gallery

sailingdog · #10 (**permalink**) 11-03-2010

Quote:

Originally Posted by sapster77

I am desperately trying to upload some pictures of the keel, but it keeps saying "upload failed". Does anyone know how to upload pictures? The are .jpg, less than 97KB and less than 800x600...

Post the photos to Flickr.com or photobucket.com and then link to them here. Read the POST in my signature to find out more.