Hit a rock. Minor Keel damage. How to repair

[Stujac]

Hi All,
I hit a rock last year in my new (used) Hanse 470. The ding is at the front bottom of the keel, not serious and nothing structural but there is roughly an 8'x 8" ding on the leading lower edge of the keel, maybe 2-3" deep - it looks like it mostly disturbed epoxy or Bondo type stuff - not quite all the way to the lead (must have been previously repaired).

I would like to take a swing at repairing and faring this myself but I am a total Newbie when it comes to epoxy, glass and this kind of stuff ...

Could one of you folks give me some advice .....

1. what tools and gear I will need (tools, epoxy, glass, ...)
2. what repair steps (e.g. first grind, then ....)
3. any "gotchas" like - apply this right away after grinding, etc.
and/or
4. point me to any videos or books or posts ...

thanks so much

[tbodine88]

Me too

[Orion Jim]

Originally Posted by Stujac

Hi All,
I hit a rock last year in my new (used) Hanse 470. The ding is at the front bottom of the keel, not serious and nothing structural but there is roughly an 8'x 8" ding on the leading lower edge of the keel, maybe 2-3" deep - it looks like it mostly disturbed epoxy or Bondo type stuff - not quite all the way to the lead (must have been previously repaired).

I would like to take a swing at repairing and faring this myself but I am a total Newbie when it comes to epoxy, glass and this kind of stuff ...

Could one of you folks give me some advice .....

1. what tools and gear I will need (tools, epoxy, glass, ...)
2. what repair steps (e.g. first grind, then ....)
3. any "gotchas" like - apply this right away after grinding, etc.
and/or
4. point me to any videos or books or posts ...

thanks so much

You stated you have an eight foot by eight inch “ding” on the leading edge of your keel which is two inches to three inches deep.
If this is accurate I’d haul the boat and seek expert advise. You may have damage which is not readily apparent.
The damage you described is not minor….

[Tetepare]

See above.

Find out what the damaged material is. You might need fiberglass filler, or might be able to glob in Marinetex. Photos are helpful.

[tkeithlu]

That would be a lot of Marinetex.

Yeah, if that wasn't a typo, you had an OH, S##T moment. It's not just the leading edge that needs inspection, you need to inspect the inside and outside of the hull before and after the keel, as well as the keel bolts. A blow like that causes the keel to rotate, pulling the hull down in front of the keel and up behind it. Aside from the buckled fiberglass, longitudinal frames (stringers) may be damaged or separated from the hull. The keel bolts may be broken, or may have broken the fiberglass they are bedded in.

So, you've got some serious poking and prodding ahead of you. I do hope that it goes well, and that you'll be back on the water soon.

[Stujac]

Correction, the ding is 8 inches by 8 inches and a couple of inches deep.

Apologies for the confusion.

[psk125]

As has been suggested, major structural problems can be caused by 'dings' such as this. Internal spaces and bolts should be checked very carefully for damage, along with what's visible from the outside. You do not want to patch up the 8" square and then have the whole keel fall off. Patching up the front of the keel is pretty simple. Chip or grind it back to solid material, mix up some epoxygoop (microfibers might be better than balloons for this, and make it a stiff mixture) and see how good you are at sculpting it back into shape. The mix will be easier to shape BEFORE it kicks, so don't just slap on gobs and think you'll sand it down afterwards. When you have it back to a respectable shape (some sanding may be called for) you should probably put a coat of epoxy sealer over it, and then your anti-fouling paint. Not even a whole weekend, really, since you can do other things while you wait for the epoxy to set.

[hugosalt]

If you expose lead during repair be sure to clean up and prime/epoxy area as anti fouling
does not adhere well to lead.

[Cyrus Safdari]

Details on usual patching of damaged fiberglass itself (aside from 2ndary damage from impact) goes like this

1- grind back any damage and delamination with an angle grinder I prefer 40 or 60 grit flapdisks for this, you have to grind back to bare fiberglass hull a few inches around the damages area too, so going past bottom paint, barrier paint even gelcoat until you see bare fb hull

2- fill with marine filler, ideally you can mix own with epoxy or use pre-made (polyester, vinylester) stuff but NOT auto bondo which dries with pinholes and absobs water (compare consistency of Bondo to 3M Marine Premium filler) wait until it dries then sand smooth (but sand it down little lower than surrounding area, to leave some room for a layer of glass in next step) I would not go with just a glob of fillerfor an 8"x8" area (at least 10x10 after grinding), I'd glass it over too. Filler absorbs moisture

3- cover with fiberglass matting and mixed epoxy resin, use a roller to get all air out from under matting . This step takes a little experience to do without a mess, especally upside down, to make sure there are no air bubbles etc. You have to glass over the damaged area plus a few inches around it. ( I cut bristles on a disposable 2" chip brush to about half length to apply the glass to the surface and dabb out airpockets, it helps reduce mess with upside down glassing)

The standard marine FB fabric stuff is called 1708 Biaxial but that could be too thick depending on the shape of where you're working. FB matt or fabric doesn't go around outside bends easily without creating airpockets so outside surface bends have to be curved smooth (and inside bends need preapplication of fillets at the joint) and/or use lighter fabric to conform to the surface shape better. Can use West epoxy system or frankly any brand epoxy just make sure you mix it right ratio (1:5 ratio for West) and right Temps, no rain etc

4- after the epoxy cures, use a sander or grinder with 80 or higher grit, and sand down smooth, carefully feathering the new glass with old around the spot. Because this is underwater it hardly needs to be perfect Then comes gelcoat , ideally barrier paint and then bottom paint reapplied.

In and encapsulated keel any Exposed lead has to be cleaned well and the surface roughed up for epoxy to grip but in reality, any metal to fb grip is doomed and Itll fall apart sooner rather than later, but as long as the lead is structurally contained it isnt a big deal. In some boats, water tends to accumulate in any voids between the lead and the interior of FB keel, this becomes an issue in freezing temps

[desodave]

You say "not serious and nothing structural" ... what inspection/survey work have you done? An impact low down on the keel maximizes the leverage of the keel, and can cause considerable damage (as per tkeithlu in post #5) if you hit it at any speed - your boat is over 27,000 lbs and the rock didn't move. Our previous boat [H38] was grounded (hit a rock) while in charter and the impact was halfway up the keel ... still caused lots of damage especially behind the keel. Insurance covered it but it was in excess of a $20,000 Cdn repair, 15 years ago.

[Dougtiff]

To hold the goop in place, screw in a couple of screws into the damaged area, this will hold the goop in place while curing.

[Cheechako]

Originally Posted by Stujac

Hi All,
I hit a rock last year in my new (used) Hanse 470. The ding is at the front bottom of the keel, not serious and nothing structural but there is roughly an 8'x 8" ding on the leading lower edge of the keel, maybe 2-3" deep - it looks like it mostly disturbed epoxy or Bondo type stuff - not quite all the way to the lead (must have been previously repaired).

I would like to take a swing at repairing and faring this myself but I am a total Newbie when it comes to epoxy, glass and this kind of stuff ...

Could one of you folks give me some advice .....

1. what tools and gear I will need (tools, epoxy, glass, ...)
2. what repair steps (e.g. first grind, then ....)
3. any "gotchas" like - apply this right away after grinding, etc.
and/or
4. point me to any videos or books or posts ...

thanks so much

Hmmm... 2-3" that's pretty deep! Hopefully no water got in there, but I imagine it did...?
I hit one in my Passport, actually two different times, at 4.5-5 knots to a dead stop. (I almost hit the floor! The wheel hand grab saved me.) My damage was maybe 8" long but only 1/4" to 3/8" deep gash at the front lower edge of the keel.

A Catalina 42 charter at the place I worked hit a rock here in Puget Sound at 5 knots. It had to be lifted out of the water and it was over $20k damage. Hull crack, engine bed came loose, part of the galley cabinets were loose.

[kryg]

If the keel is bolted on to the hull, you urgently need to inspect the Keel bolts. Ensure they have not lost their integrity. This is how some boats lose their keels. It is a must-do if it is an impact that removes a big lump of filler as you have stated.

Originally Posted by Stujac

Hi All,
I hit a rock last year in my new (used) Hanse 470. The ding is at the front bottom of the keel, not serious and nothing structural but there is roughly an 8'x 8" ding on the leading lower edge of the keel, maybe 2-3" deep - it looks like it mostly disturbed epoxy or Bondo type stuff - not quite all the way to the lead (must have been previously repaired).

I would like to take a swing at repairing and faring this myself but I am a total Newbie when it comes to epoxy, glass and this kind of stuff ...

Could one of you folks give me some advice .....

1. what tools and gear I will need (tools, epoxy, glass, ...)
2. what repair steps (e.g. first grind, then ....)
3. any "gotchas" like - apply this right away after grinding, etc.
and/or
4. point me to any videos or books or posts ...

thanks so much

[Stewie12]

You need to let the water run out. That could take weeks on the hard. Then just fill it in with glass fibre. No big deal,

[kmacdonald]

I hope this doesn't turned into a dropped keel thread. Its how they usually begin.