Our I20 daggerboards keep sliding down whenever we hoist them up (for downwind or heavy airs). Trying to figure out what to improve:
- Carpeting? The carpeting at the bottom daggerboard case exit looks in good condition (recently replaced by previous owner), and I also replaced the top starboard daggerboard carpeting, so I don't think it's due to the carpeting -- unless it's just too thin. I did notice that at speed downwind there is a lot of water bubbling up the daggerboard case, but I think that's normal?

- White rubber friction piece at top of daggerboard case? (no idea what to call it) This looks like it could add enough friction to keep the board in place - looks worn our on each side.

Daggerboard case pics (port and starboard):



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SL
Nacra Inter 20 (sold)
2017 Race to Alaska "Team Ketch me if u can"
- Facebook: https://www.facebook.com/TeamKetch/
- Race video highlights: https://www.youtube.com/watch?v=YTWp4DP0VcA
Sausalito CA
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https://www.murrays.com/product/56-1040/

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AB
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Not familiar with your exact boat, firsthand, but the rubber tensioner on the side of the daggerboard port is supposed to provide tension. I do have experience with them on other craft, and depending on the boat, they are slotted so you can move them inboard and outboard.
I have replaced these on monohulls with a heavy piece of rubberized material with a slot so I could adjust. Can be a bit finicky to get exact tension.

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Supercat 15
Windrider 17
Several Sunfish and Sunfish clones
Ratboat built from Zuma and Sunfish parts
Shallow water sailor in the Delaware Bay
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southstars2012

- White rubber friction piece at top of daggerboard case? (no idea what to call it) This looks like it could add enough friction to keep the board in place - looks worn our on each side.

Yours are done, they dry out, get brittle and shrink. Get a new pair.

Take the old ones and put on top of the new to get the holes right.
The board will slide easier when wet.
They should last several years, longer if kept covered when not in use.

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Ron
Nacra F18
Reservoir Sailing Assn.
Brandon, Mississippi
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coolhead

https://www.murrays.com/product/56-1040/

Perfect! Somehow I had missed these in my many hours browsing the Murrays site...

Glad to hear it sounds like a simple enough fix.

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SL
Nacra Inter 20 (sold)
2017 Race to Alaska "Team Ketch me if u can"
- Facebook: https://www.facebook.com/TeamKetch/
- Race video highlights: https://www.youtube.com/watch?v=YTWp4DP0VcA
Sausalito CA
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I put the rubber on both sides of each board slot
No more problems

My opinion, install a single line upfucker system like the C2's use, or a 2:1 purchase up to the shroud like some Infusions are running. The rubber stoppers always wear out, scratch your boards and fail when you need them most. I'd also consider shaving back the trailing edge of the board that is in the trunk, its doing nothing but providing a razor sharp edge when sailing downwind with the boards up.