I have a golfball size chunk out of the leading edge of a keel boat about 3ft up from the bottom of the keel and 3ft. down from the boat. How should I fix this? What specific products should I use?

Thanks,
Mike Hill

If this is a monohull, you will need to fix this by sinking the boat - use lead or a good hole saw. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Seriously though, what's the keel made of? Is it a keel/fin that's made of lead? You can solder lead back in to fill the chunk. Otherwise, if the spot is stable, you might think about filling it with Bondo - but it sounds like a pretty big hole for that.

Presuming you can take the boat out of the water so you can work on it dry:

If it is not structural then I would use epoxy. To fill in the hole you might consider mixing West Systems Epoxy with an appropriate amount of Coloidal Silica to make a rather paste. Fill the hole until you are about 1/4 inch from the surface. Next I would use the same epoxy and mix in chopped fiberglass to a rather thick consistancy and fair it in to the 1/4 inch of the surface. While the epoxy is still in the "green" stage you can trim it so there will be little sanding.

Later,
Dan

Yes, it's well above the lead. It's just fibreglass. I was thinking I could fill it with epoxy somehow. Can you give me specific links to what I need. That would help a lot. Not structural at all. I just don't want it to pop out. There will be a coat of bottom paint going over the whole keel when finished.

Alright, who was driving?

Probably the person who's most worried about it being fixed <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />

Get Bondo with fiber impregnated into it. It'll be strong, easy to shape after it sets up and will take paint well.

Mike:

Go to this site West Systems then to Product information. Go down about half way and you will find the Colliodal Silca. You can use either the slow or the fast method by choosing the hardener (slow or fast). You can get fiberglass cloth, or mat and use scissors to get the chopped fiberglass. All of these items can be found at West Marine. West Systems at West Marine

Later,
Dan

I would use Evercoats formula 27, much like bondo developed for a marine environment,although I know Jake has had good sucess with bondo.

From someone who has done MAJOR fiberglass bottom work, here's a couple of things.

1. How long was the boat in the water with that hole? If very long at all, you may want to try to borrow a moisture meter to check and see if/how wet the surrounding glass has gotten.

2. How much damage does the surrounding glass have? If it's delaminated, it will need to be ground out till you get to solid glass again. The combination of wet and damaged could lead to blisters around the area in the future.

3. Something like that, we always filled in with replacement fiberglass and resin. You say the size of a golf ball, so I would put that on borderline glass vs. bondo. IMHO, below the waterline on a mono, structural or not, anything more than just a thin layer for fairing, I'd use glass. You would do that just like any other glass project. Remove all damaged material and paint first. Overlap with the original material and put on a layer, wait, put on a layer, wait. Then once it's built back up beyond it's original level, fair back off to be even with the surrounding hull.

4. If you don't use glass, make sure to use a barrier coat before applying the bondo, want to make 100% sure that the glass is sealed since you have the center exposed. You are more likely to have water intrusion and subsequent delamination later. Believe me I've taken a sand blaster to the bottoms of boats that only look to have mild to moderate blistering, only to find that a LOT of glass is delaminated by water intrusion.

I would recomend that you add some mill fiber whenever you mix a batch of putty using epoxy or vinylester resin. The mill fiber makes the resin strong. C. silica is just a filler to thicken the mix.

I've seen larger batches of resin without mill fiber and just C.silica crack while curing.