Sealing mast
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- Rank: Lubber
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Posted: Oct 30, 2021 - 10:38 PM
During my first capsize in my 1999 Nacra I-20, my carbon mast wanted to sink. Managed to keep it up, but close to turtling. I removed the base cap and planned to fill the mast with water to see if I have leaks. Found it filled with expanded foam. Can I still add water from a garden hose to look for leaks? Or will the water just make the foam soggy? -
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Posted: Oct 31, 2021 - 08:54 AM
If there is any way to apply a small fitting to pressurize the mast with low-pressure air from a balloon pump, you can use a soap solution to identify and mark the leaks for sealing. I would not want a mast filled with foam as it increases weight and can hold water. Do you suppose that was added by a previous owner? I can't imagine why a lightweight carbon mast would be filled with foam.
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Tom
NACRA 5.7 (1984 Sail 181)
Pennsylvania
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Posted: Oct 31, 2021 - 09:29 AM
It is fully normal with a layer of foam in masts, as it is often used for sealing tip and base, do you know yours is completely filled?
Are you sure the mast is leaking, if so you should see where the water leaks out?
Note, the floation from a sealed mast should be in the ballpark of 5kg/m, depending of mast section and wall thickness.So it is fully normal that at least the first meter of the mast is below surface before you right it.
If you want more floatation, get a mast float from Hobie.
Edited by revintage on Oct 31, 2021 - 01:10 PM.
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Brgds
Lars
Frankentri 5.8/5.5/Inter20
Aerow trimaran foiler
https://www.facebook.com/groups/1192604934176635
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Posted: Oct 31, 2021 - 09:36 AM
Don't do it. Even though water isn't supposed to mitigate through "closed cell foam", take a pragmatic approach and get your tube of silicone and put some around every rivet.
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Bill Townsend
G-Cat 5.0
Sarasota
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Posted: Oct 31, 2021 - 09:49 AM
You did well to keep the mast floating. Our first I20 capsize ended turtled. The I20 has a composite mast head fitting and uses a foam plug to seal the top of the mast. I don't think the bottom is supposed to be sealed with
foam. The best way to check for leaks is to take the mast into the water and sink it. You will see bubbles at each leak. Obviously this requires you to be at the beach or swimming pool. That said you don't really need to find the leaks, as shorty said just seal everything from the mast hound up and you will be good. It is good if there is a
leak near the base to let any water out. I also propped the mast up and filled the mast head completely with water and let it sit for a few hours to test the top foam plug. Mine was sealed. When you righted the boat did water come gushing out of the mast? Are you sure you had water in it? The mast will sink quite a bit even sealed, but bobs up and down. Ours filled and needed a power boat to get it back over.
Pete
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Pete Knapp
Schodack landing,NY
Goodall Viper,AHPC Viper,Nacra I20
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Posted: Nov 01, 2021 - 03:26 PM
I can't say if water came out of the mast when righted. The weather was heavy and I was spent and in the water trying to get back on. But during my righting attempts, every time I moved to reach around the tramp to get things set up, the mast started going down. I'd spend a few seconds at most grabbing something like my water bag... and each time was a close call. I almost had it up twice, but then I'd end up with the water bag hitting the water and it would settle back down on ots side. After that, I couldn't even get that far so I was either spent, or the mast took on water and I didn't have a hope after that. Anyway I got a pulled back up by a watchful Jeneaux 45 that I happened to have sailed on before. So I new my rescuers. I'm working on a righting pole because the water bag really knocked me out. I'll have both.
I'll just seal and do a sink test. I won't bother with the garden hose method I planned on because of the foam plug at the base of the mast. I have no idea how far the foam goes, but it may have been DIY great stuff. Looks like it. I may probe and remove some and see how it goes. -
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Posted: Nov 01, 2021 - 04:33 PM
If you had the mast out of the water & couldn't right it, I'd check your hulls. Usually when I got that result I'd find a hull had a leak which makes righting difficult & capsizing easy
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Chuck Miles
1978 Hobie 16
1991 Hunter 23.5
TsaLaGi Yacht Club, Jackson Bay Marina
Fort Gibson Lake, OK
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Posted: Nov 01, 2021 - 06:39 PM
Are you using a block and tackle to raise your water bag or just lifting it? We spent quite a bit of time practicing
righting the I20 in no wind conditions. We are a fairly light crew and just when it seemed we would not succeed,
we got the blocks set correctly and I was able to just lean on the bag and it came over quite easily. You found out how frustrating the bag can be when it hits the water all effort stops. Practicing in low wind conditions will give you the confidence that you can do it with more wind to help. It also allows you to observe the mast to see if it will stay afloat. If the wind is behind the tramp it will drive the mast down. It is imperative to get the mast into the wind. There was some discussion recently about using an anchor to hold the boat correctly. For us we were in a hundred feet of water so an anchor would not have helped.
Pete
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Pete Knapp
Schodack landing,NY
Goodall Viper,AHPC Viper,Nacra I20
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Posted: Nov 02, 2021 - 11:01 AM
Or remove the mast base and put some rags to fill the space around a hose with which you will apply pressure, you really need little pressure, might even use your lungs. Or your asistant's, because you want to be on the other end of the mast..
A good way to seal the top of the mast is to insert a plug inside, underneath the mast head. You may steal a cutting board from the kitchen and cut it to match the inner section and apply enough sealant around the edges. Add something to grab it, to be able to handle it inside the mast. -
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Posted: Nov 03, 2021 - 06:24 AM
All this and...
It's helpful to have one person get at least partly in righting position quickly to counteract turtling forces while the other uncleats sheets, deploys righting line and bag, etc. I run my righting line under my trap hook and it catches on a strategically placed stopper knot when I'm extended just above the water. That way my arms don't get immediately exhausted from holding myself up and they are free to manipulate the bag (large Murray's bag with block, tackle, and cam cleat). The hardest part is getting/keeping the bag full of water. Then it's sort of an iterative process of raising the bag a little and climbing the righting line a little (more strategically placed knots for handholds). It's a no-fun PITA, but it works for me.
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Jerome Vaughan
Hobie 16
Clinton, Mississippi
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Posted: Nov 10, 2021 - 09:34 AM
My older Tornado mast has foam at the top. The idea was for when they capsize because the masts aren't sealed, they have an internal jib halyard. Unfortunately, if the foam gets wet, it will cause corrosion and pitting of the mast. I would suggest just sealing the mast real well, but have a "drain" at the bottom. You can drill and tap a 10-24 PHMS if you don't want to keep it open.
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Scott
Prindle Fleet 2
TCDYC
Prindle 18-2 Mod "FrankenKitty"
Tornado Classic "Fast Furniture"
Prindle 19 "Mr. Wiggly"
Nacra 5.8 "De ja vu"
Nacra 5.0
Nacra 5.8
Tornadoes (Reg White)
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Posted: Dec 04, 2021 - 12:31 AM
Pete, I think you are right. It was probably wind on the tramp that pushed the mast head down. I couldn't spend enough time on the bow to get it upwind, since I was alone. I did have the Murray's bag kit. Going to need a righting plank I think to self right. I need more leverage.
