Keel Repair

[clearhair]

Hi all-

Recently bought a Sunfish hull very cheap, but it came with fully functional rig, rudder, and daggerboard. Those whole thing cost 300$, which the sails/rig/rudder and hardware alone was worth that, and the hull is in good condition with the exception of a large hole/crack in the aft section of the keel.

I cannot tell whether the internal structural foam has been rotted away (it was stored, uncovered, in a field for many years, alas) but I have a good idea of how to fix the hole, and I was checking to see what the consensus was from people who have more experience with these boats. I have had extensive experience working with composites when I studied at the Naval Academy (Naval Architecture major) so I have a good idea of how to go about things, but any practical advice is appreciated.

Planned repair:

Potentially install 6" ports aft of cockpit well to get at the hole from two sides.
Sand bottom of hull down past gelcoat to bare glass, Dremel away rough edges.
Fill hole with Cabasil-thickened epoxy, layer each side with 5 layers 6-oz. cloth at 0/90, +/- 45, 0/90 orientation.
Cover bottom with layer of fine 1-oz cloth prior to finish sanding and repainting.


Any suggestions will be welcomed.

 

[Webfoot]

Sounds like you're using the band-aid patch method. It does work but you end up with the fiberglass patch resting above the surface. I've done this and it leads to adding filler to try and hide the hull-wart. Better to use the standard method easily found in instruction books and on the web. It is tempting not to do a cut-away on the bad section and use filler instead. Think of it this way, this is practice for when you get that $600,000 Go Fast Boat and it needs a hole patched. You'll need to know how to do a 100% structurally correct and invisible repair.

 

[petersarazin]

The used sunfish I recently bought has a couple of small ( 1/4" x 3/4" ) areas along the edge of the keel board where the gelcoat has chipped away and you can see bare fiberglass. The fiberglass appears undamaged and there are no leaks.

At first I was thinking of using a gelcoat repair technique, but I went to West-Marine today during lunch and they suggested that I keep it simple and use white marine-tex to repair these 2 small areas.

The guy I spoke with suggested marine-tex over gelcoat because te repair is under the hull where it mostly will not be visible, and he said marine-tex would provide a much more durable patch.

I just wanted to throw this out for discussion and see what the experts on here think...

Thank you.

 

[Zeppo]

If it's a non structural repair I would definitely pick Marine Tex over gelcoat.