Maintenance story / Rassvet · Ohlson 29
Keel joint: a story of three seasons
Rusty leaks at the junction of the keel and the hull led first to repairs at the shipyard, and then to independent maintenance of the seam.
Entry dated December 5, 2023
First rust marks
Inspection after lifting, conversation with the previous owner and contacting the shipyard. The record contains photographs and the cost of the first repair.
All stage pictures7 photos · 1 video
Read full entryCollapse entry
When I lifted the boat for cleaning in September, I saw rust at the keel-to-hull joint. My heart sank: that couldn’t be good. Thoughts raced through my head, including selling this yacht I’d spent more time fixing than sailing.
Once calmer, I approached the only expert I know and trust: @AlexMemfis. His consultation cost €100. After studying the photos and video, he sympathised and said this was precisely why lifting a boat to inspect the hull before purchase mattered. I’d been unlucky. First, he suggested asking the previous owner what he knew. So I did.
Erik replied that he knew about the problem, but it hadn’t looked as serious before. He’d filled those areas with epoxy, which apparently proved too rigid and cracked. He suggested grinding away the corrosion, filling with epoxy, then applying a flexible sealant such as Sikaflex.
@AlexMemfis agreed with Erik, but suggested asking the marina for a quote and declining if it exceeded €1,000–1,500. He also said corroded keel bolts would need replacing.
When laying up the boat for winter, I asked the DavidWerft team and explained all my concerns. A week later, they invoiced €1,210, which I paid straight away. The photos show the rust marks, their removal and the sealed repair.
#maintenance
Once calmer, I approached the only expert I know and trust: @AlexMemfis. His consultation cost €100. After studying the photos and video, he sympathised and said this was precisely why lifting a boat to inspect the hull before purchase mattered. I’d been unlucky. First, he suggested asking the previous owner what he knew. So I did.
Erik replied that he knew about the problem, but it hadn’t looked as serious before. He’d filled those areas with epoxy, which apparently proved too rigid and cracked. He suggested grinding away the corrosion, filling with epoxy, then applying a flexible sealant such as Sikaflex.
@AlexMemfis agreed with Erik, but suggested asking the marina for a quote and declining if it exceeded €1,000–1,500. He also said corroded keel bolts would need replacing.
When laying up the boat for winter, I asked the DavidWerft team and explained all my concerns. A week later, they invoiced €1,210, which I paid straight away. The photos show the rust marks, their removal and the sealed repair.
#maintenance
Entry dated March 5, 2024
Shipyard work
Inspect the keel mounting, update nuts, washers and sealant. The rigid filling of the joint is replaced by an elastic one.
All stage pictures6 photos
Read full entryCollapse entry
The marina wrote at the start of February. They reported that they’d finished the keel work and sent the winter-service invoice.
About the keel: they visually inspected the bolts and judged them sound. Nuts, washers and sealant were renewed. They removed the epoxy between keel and hull, sanded the joint and filled it with polyurethane. They said there had been a lot of resin; its rigidity had eventually caused a crack. Polyurethane is more flexible, and a thin layer won’t split under internal pressure. A small ledge now shows between keel and hull, where epoxy had previously filled the space.
The winter service included:
— draining the waterlock/silencer
— filling the hoses with bio-antifreeze that can safely be discharged into the sea
— pumping out and disposing of the old engine oil, then refilling
— the same for the gearbox oil
— replacing fuel and oil filters
— fitting a new zinc anode
Total, including parts: €503.
Unexpectedly, they said they couldn’t remove the oil dipstick. I went straight down to see for myself. In summer, it had been tight, but it did come out.
#maintenance
About the keel: they visually inspected the bolts and judged them sound. Nuts, washers and sealant were renewed. They removed the epoxy between keel and hull, sanded the joint and filled it with polyurethane. They said there had been a lot of resin; its rigidity had eventually caused a crack. Polyurethane is more flexible, and a thin layer won’t split under internal pressure. A small ledge now shows between keel and hull, where epoxy had previously filled the space.
The winter service included:
— draining the waterlock/silencer
— filling the hoses with bio-antifreeze that can safely be discharged into the sea
— pumping out and disposing of the old engine oil, then refilling
— the same for the gearbox oil
— replacing fuel and oil filters
— fitting a new zinc anode
Total, including parts: €503.
Unexpectedly, they said they couldn’t remove the oil dipstick. I went straight down to see for myself. In summer, it had been tight, but it did come out.
#maintenance
Entry dated April 14, 2026
Return to the node itself
After the reappearance of smudges, do independent cleaning, priming, sealing and monitoring the result.
All stage pictures10 photos
Read full entryCollapse entry
Winter keel maintenance
The keel provides the righting moment, returning a heeled yacht upright. Massive metal though it is, it needs attention beyond the occasional lift-out.
A bolted keel always has a hull joint, working under load. The hull flexes; the keel takes impacts and vibration. Rigid filler won’t settle it forever. Epoxy eventually cracks, water reaches metal and quietly does what water does.
Simple principle: watertight and flexible.
My experience
Three years ago, soon after purchase and a grounding, I saw rusty streaks. The yard serviced the joint and keel fastenings: €1,200.
Next year, rust elsewhere after another gentle touch. Free repair. Again this season. Not a one-off, or a miraculous repair meant to survive everything. I need to handle this joint myself, or every stain becomes a paid news bulletin.
How I treat the joint
Step 1. Remove old sealant, open to clean metal below and sound GRP above. No patches of barely attached old material. Dremel worked well.
Step 2. Clean and degrease. I used alcohol and compressed air.
Step 3. Sika Primer 206 G+P for adhesion to keel steel and hull GRP. Don’t wait after cleaning: bare metal oxidises quickly.
Step 4. After thirty to sixty minutes, fill with Sikaflex 291i or 292i. A continuous, flexible seam without voids.
Step 5. Once cured, lightly fair the sealant. Restore epoxy primer damaged around the keel edges, but don’t coat the sealant itself with epoxy. Antifouling only over it.
Rust on the keel
Separate rusty spots too: a touch of bottom, overenthusiastic sanding last season. Whatever caused it, protection needs renewing.
My sequence:
1. Clean back to bare metal.
2. Rust converter.
3. After treatment, key with an abrasive pad and apply epoxy primer. Repeat to four or six coats.
4. Then antifouling.
Almost exemplary this time, except I remembered rust converter after the first primer coat. Now observe, call it a field trial, and get the order right next season.
#service
The keel provides the righting moment, returning a heeled yacht upright. Massive metal though it is, it needs attention beyond the occasional lift-out.
A bolted keel always has a hull joint, working under load. The hull flexes; the keel takes impacts and vibration. Rigid filler won’t settle it forever. Epoxy eventually cracks, water reaches metal and quietly does what water does.
Simple principle: watertight and flexible.
My experience
Three years ago, soon after purchase and a grounding, I saw rusty streaks. The yard serviced the joint and keel fastenings: €1,200.
Next year, rust elsewhere after another gentle touch. Free repair. Again this season. Not a one-off, or a miraculous repair meant to survive everything. I need to handle this joint myself, or every stain becomes a paid news bulletin.
How I treat the joint
Step 1. Remove old sealant, open to clean metal below and sound GRP above. No patches of barely attached old material. Dremel worked well.
Step 2. Clean and degrease. I used alcohol and compressed air.
Step 3. Sika Primer 206 G+P for adhesion to keel steel and hull GRP. Don’t wait after cleaning: bare metal oxidises quickly.
Step 4. After thirty to sixty minutes, fill with Sikaflex 291i or 292i. A continuous, flexible seam without voids.
Step 5. Once cured, lightly fair the sealant. Restore epoxy primer damaged around the keel edges, but don’t coat the sealant itself with epoxy. Antifouling only over it.
Rust on the keel
Separate rusty spots too: a touch of bottom, overenthusiastic sanding last season. Whatever caused it, protection needs renewing.
My sequence:
1. Clean back to bare metal.
2. Rust converter.
3. After treatment, key with an abrasive pad and apply epoxy primer. Repeat to four or six coats.
4. Then antifouling.
Almost exemplary this time, except I remembered rust converter after the first primer coat. Now observe, call it a field trial, and get the order right next season.
#service
According to the last entry
How the story ended
In the spring of 2026, the seam was serviced independently. In the last entry, the author leaves the result under observation until the next season.
Open last stage ↗