In this publication5 photos
In autumn, cracked window sealant began leaking. I’d applied Sikaflex 591 eighteen months earlier, after accidentally pressure-washing the previous seal away.
More thorough this time. My acrylic windows sit in rubber glazing seals with locking strips, rather than being bonded directly into the hull. The rubber holds them mechanically; sealant adds water protection.
Simple plan: locking strip out, old sealant removed, primer, new sealant, strip back. In reality, it was 8 March 2026, a date I no longer associate with celebration.
Preparation
Strip out, old sealant removed with fingernails and screwdriver. First questionable choice. The screwdriver slipped, scratching acrylic. A frown. Then white paint scratched. A pause to silently calculate what haste had gained.
By the end, sealant beneath nails, nails bleeding. Feelings exhausted; only an inner voice: ‘You must.’
Primer
Sika Primer 209D inside the seal and on acrylic edges. More than ‘paint for adhesion’: it prepares acrylic for polyurethane sealant, leaving a black activating film. Careless marks can remain.
Mine did. Even without the strip, rubber kept closing against the window, especially awkward overhead. Primer runs on acrylic, ingrained rather than wipeable. I fear only sanding the acrylic surface will remove them fully.
Sealant and nozzle
Sikaflex-295 UV this time: specified for acrylic and polycarbonate yacht windows, UV-resistant and flexible. Not the main mechanical fixing in my rubber seal, but hopefully a better external flexible seam.
At first, terribly hard to squeeze. I blamed tube age, temperature, gun, general injustice. At window two, simpler cause: nozzle hole too small. Cut wider, much faster. Unpleasant but useful lesson: sometimes the hole, rather than the material, is inadequate.
Locking strip
Refitting it ended the plan’s last resemblance to reality.
Lying on my side, forcing it into the groove with a screwdriver. Fingers, wrist, arm, side, neck hurting. One inaccurate movement, ten fitted centimetres popped out. Six windows, four hours.
Now I know there’s a proper locking-strip tool. Stubbornness is cheaper than a tool, but by window four the savings look questionable.
Cleaning up
Strip finally in, excess sealant squeezed out. Tired, I used wet wipes: second questionable choice. In the cramped space, sealant onto clothes, clothes onto white hull, then attempts to clean it spread it farther.
By evening, satisfaction came from finishing, at least temporarily. Hopefully longer than eighteen months this time. If I return to these windows, first a proper tool, or serious thought about another mounting system.
#maintenance
More thorough this time. My acrylic windows sit in rubber glazing seals with locking strips, rather than being bonded directly into the hull. The rubber holds them mechanically; sealant adds water protection.
Simple plan: locking strip out, old sealant removed, primer, new sealant, strip back. In reality, it was 8 March 2026, a date I no longer associate with celebration.
Preparation
Strip out, old sealant removed with fingernails and screwdriver. First questionable choice. The screwdriver slipped, scratching acrylic. A frown. Then white paint scratched. A pause to silently calculate what haste had gained.
By the end, sealant beneath nails, nails bleeding. Feelings exhausted; only an inner voice: ‘You must.’
Primer
Sika Primer 209D inside the seal and on acrylic edges. More than ‘paint for adhesion’: it prepares acrylic for polyurethane sealant, leaving a black activating film. Careless marks can remain.
Mine did. Even without the strip, rubber kept closing against the window, especially awkward overhead. Primer runs on acrylic, ingrained rather than wipeable. I fear only sanding the acrylic surface will remove them fully.
Sealant and nozzle
Sikaflex-295 UV this time: specified for acrylic and polycarbonate yacht windows, UV-resistant and flexible. Not the main mechanical fixing in my rubber seal, but hopefully a better external flexible seam.
At first, terribly hard to squeeze. I blamed tube age, temperature, gun, general injustice. At window two, simpler cause: nozzle hole too small. Cut wider, much faster. Unpleasant but useful lesson: sometimes the hole, rather than the material, is inadequate.
Locking strip
Refitting it ended the plan’s last resemblance to reality.
Lying on my side, forcing it into the groove with a screwdriver. Fingers, wrist, arm, side, neck hurting. One inaccurate movement, ten fitted centimetres popped out. Six windows, four hours.
Now I know there’s a proper locking-strip tool. Stubbornness is cheaper than a tool, but by window four the savings look questionable.
Cleaning up
Strip finally in, excess sealant squeezed out. Tired, I used wet wipes: second questionable choice. In the cramped space, sealant onto clothes, clothes onto white hull, then attempts to clean it spread it farther.
By evening, satisfaction came from finishing, at least temporarily. Hopefully longer than eighteen months this time. If I return to these windows, first a proper tool, or serious thought about another mounting system.
#maintenance
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