FIBERGLASS REPAIR

Apr 29, 2012
216
Beneteau 35s5 bristol ri
I need to do some fiberglass work on my keel. I ran aground and the bottom of the keel is damaged. I'm thinking polyester resin and some cross chop batting. Any helpful tips?
 
May 17, 2004
5,028
Beneteau Oceanis 37 Havre de Grace
Is the rest of the keel encased in anything? It’s very common for the keel to just be coated in epoxy and painted. If that’s how the rest of yours is then I’d just clean, prime, fair, and barrier coat. You don’t really need anything structural, just a way to make it smooth, and keep the water off the keel if it’s iron.

If the rest of the keel is actually encased in glass than grinding back to clean material, adding some polyester and mat, and fairing sounds ok.
 
Apr 29, 2012
216
Beneteau 35s5 bristol ri
It's a Beneteau 35s5 with the deep lead keel. I do think it is encased in fiberglass.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
Do not use polyester resin in this application. Polyester has poor adhesion properties compared to epoxy. Follow the West System Manual for keel repairs on their site.

Are you sure the keel is lead? I thought most Beneteaus had cast iron keels?

Have you inspected the rest of the boat for damage from the grounding? Places to look are at the aft end of the keel stub and surrounding laminate, the forward end of the keel stub and the the laminate and the interior structures. In a grounding the keel acts as a lever and can apply a lot of force to the hull cause interior damage to the structure and causing the hull to delaminate.
 
Jun 2, 2007
403
Beneteau First 375 Slidell, LA
I could be wrong, but I think the deep keel on the 35s5 actually was made of lead, and I'm pretty sure it wasn't encapsulated. Probably the damage you see is to fairing material, which is easily repaired with epoxy thickened with microballoons. As dlochner says, you should carefully check out the hull and interior structure supporting the keel.
 

kmart

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Jan 1, 2012
87
Pearson 10M Fall River, MA
I actually have a similar repair. Damage on bottom of keel from a wave droping on a rock. In my case keak is lead encased in fiberglass. Damage is the fiberglass on bottom and leading edge got chewed up. I used an angle grinder with wire brush. Got lead shiny. Used 60 grit to smooth out all the fiberglass. Then west ststem appoxy and structural filler. Got it to penut butter consistacy. Filled in and smoothed everything out. Do t k ow if this is best way to fix.. but oir came out decent for my needs
 

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Mar 1, 2012
2,182
1961 Rhodes Meridian 25 Texas coast
I could be wrong, but I think the deep keel on the 35s5 actually was made of lead, and I'm pretty sure it wasn't encapsulated. Probably the damage you see is to fairing material, which is easily repaired with epoxy thickened with microballoons. As dlochner says, you should carefully check out the hull and interior structure supporting the keel.
I wouldn't use micro balloons underwater. They are after all tiny balloons. I'd use silica instead.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
I wouldn't use micro balloons underwater. They are after all tiny balloons. I'd use silica instead.
Silica makes the epoxy extremely hard which makes for difficult sanding and fairing. A thin final coat or two of epoxy thickened with micro-balloons works, except they are prone to pinholes. If an expoxy barrier coat is going over the top, this isn't an issue.

Interlux makes a very nice underwater fairing compound, Watertite. Easy to apply and sands easily. Jamestown Total Boat makes a similar product.
 
Apr 29, 2012
216
Beneteau 35s5 bristol ri
ended up using epoxy putty bacaus there was a dent in the lead. So easy to work with. I put it on yesterday. checking in on it Thursday. Thanks for the advice about polyester resin. I'll let you all know how it goes. Thanks for the feedback!