Hit a rock. Minor Keel damage. How to repair

[Stujac]

Thanks everyone. It was a bonehead, amateur move that sent me. Into a rock but for some of us (me) that is the best way to learn ...

I have checked and double checked the keel, bolts, etc;
and then had the local boat yard do the same. All good , probably thanks the 3 long bits of galvanized steel running fore with a galvy steel keel plate weleded to them. She also galvamized steel ribbing. (Still learning all the right names for this stuff). Not sure how one of the fiber grid boats would have done but this girl did not budge. She is on the hard for month.

The job is to fix the gash, keep the water out, make her keel perform, and have some fun when it warms. I am looking forward to a long weekend of learning about epoxy and fiberglass.

Any more pointers are appreciated.

[Don C L]

An old boatwright told me once, "whales have ribs, boats have frames."

Sounds like it's probably ok, but I'd like to see photos of the aft part of the keel where it enters the hull, you could have damage there that is a little hard to spot. Any cracks there? In a hard grounding like that the keel will try to rotate up into the hull in the aft.
Check articles like this one too.
https://www.yachtingmonthly.com/gear...-a-yacht-30650

[Rucksta]

Building large areas of shaped epoxy filler can be tedious and repetitive.
Mixing it wet enough to stick but thick enough not to sag is a balancing act.

I'd avoid any 5:1 mix ratio epoxies as they tend to blush with an amine coat that inhibits adhesion of the next layer.

There will be more than one layer.

Choose a 2:1 or 1:1 resin preferably a high viscosity resin rather than a laminating resin.
The 2:1 mixes tend to be blush free. and the higher viscosity gives a wetter mix when the thickness is right.

Colloidal Silica is the go to stiffening agent - Aerosil.
The dried mix will be hard to sand but strong.

Ad screws as suggested earlier to give the cured mix a mechanical bond.

Use peel ply.
This is a woven polyester release film that gives a even finish and allows wax and other by-products of the reaction to bleed out resulting in a cleaner surface for the next layer.

Core Flute can be used as formwork to hold the epoxy mix in place while it hardens.
Spray contact glue the peel ply to the core flute screw one side to the keel, trowel in excess epoxy mix, wrap the form work over the mix before it can sag and secure with screws on the other side.

Tight so the epoxy oozes out.

Wipe the excess away.
White vinegar on a rag works well it's also great for other clean up.

The formwork can be removed any time between gel and full cure.
I like to wait until at least partial cure to let the peel ply do its job.
Others like to go early and get the next layer on while the previous layer still holds a fingerprint.

Successive layers can have more easily sanded fillers added.
N.B. micro balloons can absorb water

If you get a result in three applications you are doing well.
Two and you qualify as a pro.
One application is substandard .


There are technical aspects to epoxy engineering but good technique is the most important part of the process.
Have a clear picture in mind of how (micro steps) you will achieve the result you want

Have a box of gloves and change frequently.
Buy a bag of clean cotton rags.
Tongue depressor's make good mixing sticks
Have appropriate sized measuring cups and a bigger mixing cup.
Mix the resin before adding filler.
Maintain a clean work area.
I use core flute on the mixing bench and keep 4lt resin bottles in a window washing bucket.

Everything sticky goes into the bucket then the gloves come off.
New pair of gloves for clean up

[Cabo Jim]

in about 2007 friends and I charted a Hanse 40E out of Port Sidney BC. It had just been splashed after extensive repair work from hitting a rock (A crewed charter no less). The boat grounded and when the tide went out the crew laid boat cushions between the rock and the hull. The damage from hitting the rock was so extensive they were talking about writing off the boat. In the end they ordered a new keel from Germany and completed the repair. I don't know how much structural damage was done to the hull. We were the first charter after the repair and no leaks. Hope all goes well with your repair.