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Mast Sealing and Turtleing Prevention

Posted By: JJD

Mast Sealing and Turtleing Prevention - 07/14/09 02:40 AM

blush I did a bow stuff and capsize while under spinnaker Saturday.
Couldn't keep it from going turtle. I think I might be doing something wrong there, but not sure what yet. At any rate, the mast seemed to fill from the bottom and a small leak from one of the side stays. At least that was where I found leaks after submerging the mast in my pool yesterday.
Since the top of the mast was sealed, and the bottom and stay attachment leaks are slow, when out of the water, even two lifeguard boats could not get the Blade to right, or even stay on it's side except under tow.
Had to drag it back to the beach and upend it there.
The water took at least 5-10 minutes, maybe longer, to quit draining out of the base of the mast.
I'm going to have to cut the plugs out of the top and bottom of the mast and side stay attachments and reseal.
I'm considering stuffing the mast tube with those foam plastic noodles. Anybody got a good reason that that's not a good idea? I know that they will add some weight and eventually absorb some water, but they could be replaced easier than the plugs which are made of that foam coated with sealer.
Also have to figure out what I'm doing to cause the boat to want to turtle.
Once it goes over, it seems to want to stabilize perpendicular to the wind with the full force of the wind forcing the tramp and the mast down. Maybe I just have to have presence of mind to get off fast and get to the bow to try to swim the bow into the wind.
Any suggestions?
John
Posted By: bobcat

Re: Mast Sealing and Turtleing Prevention - 07/14/09 02:54 AM

The weight will be an issue, plus if you aren't sealing it, you have lost even more flotation. So its better to address the turtle issue. I don't think the bottom plug should be much of an issue until you have turtled. You probably have your most significant leak at the diamonds and probably already had water in there from previous swims. In most cases, I don't think that the hounds even need to go under water.

On a recent capsize, I tried to stay dry and stepped down off the hull onto the mast. I managed to get slightly tangled in sheets while doing this and spent some time standing on the mast. I "freaked" when I saw how far I had pushed the mast under water. But once I got around to the underside and pulled on the dolphin striker, the masts buoyancy brought it back to the surface.
You perhaps do need to be a bit more motivated about getting the boat turned into the wind. Standing on the bows will often suffice but you could also lower yourself into the water at the bow and give some swimming kicks.
Posted By: PTP

Re: Mast Sealing and Turtleing Prevention - 07/14/09 03:52 AM

i have had to do the swimming at the bow thing to get the boat in the right orientation. The boat really doesn't want to get in the right position unless you do it because the mast and sail act as an anchor for the tramp so it wind vanes like that. It can be worse though if the mast is downwind because then it wants to make the boat turtle
if you can put the mast under the water and find the leaks then just smear the crap out of them with 5200. I did that a couple years ago where the diamonds go into the mast.
Posted By: ncik

Re: Mast Sealing and Turtleing Prevention - 07/14/09 06:48 AM

I have identified the problem with your technique...capsizing in the first place.

Seriously though, don't fill your mast with foam, corrosion and weight become issues.

Your mast sounds reasonably well sealed if it takes 5-10 mins to drain. You just need to get onto the hull earlier. Forget the spinnaker retrieval until you have the boat under control again (on it's side if need be) the retrieve kite from the hull wherever you can.
Posted By: scooby_simon

Re: Mast Sealing and Turtleing Prevention - 07/14/09 07:22 AM

Originally Posted by ncik
I have identified the problem with your technique...capsizing in the first place.

Seriously though, don't fill your mast with foam, corrosion and weight become issues.

Your mast sounds reasonably well sealed if it takes 5-10 mins to drain. You just need to get onto the hull earlier. Forget the spinnaker retrieval until you have the boat under control again (on it's side if need be) the retrieve kite from the hull wherever you can.


Disagree; 10 minutes of water, is a LOT of Water to try and lift up when it's at the bottom of the mast. 10 minutes might be 10-20 litres which is 10-20KG just where you do not want it.


I would focus on fixing the leaks

Fix all known leaks and then put it back in the pool to test it. Repeate until all found.

I had a very leaky Inter 17 mast and it took me ages to find them all.

Also, any leaks up the top of the mast will be under some pressure when you tip the boat in. a couple of feet of depth will force water into even the smallest hole!
Posted By: waynemarlow

Re: Mast Sealing and Turtleing Prevention - 07/14/09 08:53 AM

OK having had a mast which has been very water tight, the last two capsizes have ended up with water in the mast and not being able to self right, the first time I got caught in ropes and halyards on the wrong side of the hulls, ended up totally turtled for the first time, on Sunday however it was just a tip over with spinnaker up.

My question is then, what is the best method for finding out where the leaks are ? cool
Posted By: Jalani

Re: Mast Sealing and Turtleing Prevention - 07/14/09 09:32 AM

When I first got my old Stealth there was water already in the mast and I couldn't seem to get it out.... Obviously it had got in somewhere? The approach I used was to drill a hole at the side of the mast just above the foot plug and empty it (from memory it took about 3-4 mins to empty through an 8mm hole). Next step was to epoxy a Schrader car tyre valve that I cut from an old inner tube into the hole.
Once this was dry I connected a foot pump to the valve and raised the pressure VERY VERY SLIGHTLY (about 3 pumps). Then, using soapy water, I checked around all of the fittings and finally along the length of the mast. I fount that both my upper diamond attachment points were leaking and one spreader attachment. I drilled off each fitting, resealed with sikaflex and reattached the fittings. After checking again for leaks, I removed the schrader valve and epoxied over the hole. Job done!

With hindsight I think I'd have left the valve in place but made a neater job of the install......
Posted By: pepin

Re: Mast Sealing and Turtleing Prevention - 07/14/09 12:30 PM

The solution is to have leaky hulls. It makes for a more stable platform when you have two hulls full of water. Even if you fill the mast the boat is going to stay up.

Don't ask me how I know.

I fixed the 5.2 since then smile
Posted By: waynemarlow

Re: Mast Sealing and Turtleing Prevention - 07/14/09 12:40 PM

Originally Posted by Jalani
When I first got my old Stealth there was water already in the mast and I couldn't seem to get it out.... Obviously it had got in somewhere? The approach I used was to drill a hole at the side of the mast just above the foot plug and empty it (from memory it took about 3-4 mins to empty through an 8mm hole). Next step was to epoxy a Schrader car tyre valve that I cut from an old inner tube into the hole.
Once this was dry I connected a foot pump to the valve and raised the pressure VERY VERY SLIGHTLY (about 3 pumps). Then, using soapy water, I checked around all of the fittings and finally along the length of the mast. I fount that both my upper diamond attachment points were leaking and one spreader attachment. I drilled off each fitting, resealed with sikaflex and reattached the fittings. After checking again for leaks, I removed the schrader valve and epoxied over the hole. Job done!

With hindsight I think I'd have left the valve in place but made a neater job of the install......


I like that idea, will investigate further as what was a sealed mast is suddenly not, mmmm
Posted By: Timbo

Re: Mast Sealing and Turtleing Prevention - 07/14/09 01:27 PM

>>>I did a bow stuff and capsize while under spinnaker Saturday.<<<

Ok, first things first, how long did it take you to snuff the spinnaker before righting, and where were you standing when you did that?

After a spinnaker crash I get to the underside of the tramp as quickly as possible, stand on the hull, unclete the halyard. On my rig I can do this by pulling the snuff line -halyard- in the "wrong" direction from under the tramp. Then I snuff the spin from the back of the sock. Also, while you are back there, look to see if your mainsheet is uncleted, be sure it is.

As soon as the kite is in the bag, I go foreward to the low bow and sit down, drag my feet in the water to get the boat to pivot so the bows are pointing somewhat upwind, with the wind coming under the mast. When you get the boat in that possition, then you can go to your righting line (mine has small loops on each end, I just hook it onto my trap harness hook) and lean back.

If you were on the wrong side of the tramp too long snuffing the kite, or if the boat was lying with the tramp fully into the wind, the boat will be moving downwind, pushing the mast tip down and under water as it goes. So, the most important thing to do after a crash in big wind is get the mast perpendicular to the wind, then snuff the kite.

You can do this by simply hanging onto the bow, your body will be a sea anchor as you drag along in the water, and the kite being in the water should also help turn the mast upwind.
Posted By: pepin

Re: Mast Sealing and Turtleing Prevention - 07/14/09 01:32 PM

Talking about sealing rivets, I don't like the little plastic bits you put in rivets to seal them. They have a tendency to fly away and they degrade quite quickly. On my Hobie (a long time ago) I used rivet casing to seal the fittings: you put the casing in the mast and pop the rivet into it. This has numerous advantages: no broken rivet head rolling in the mast and a tight fit that will not leak, especially if you dip the casing in silicone first.

At some point I had monel rivet casing, and I've seen aluminum ones. But I can't find those anywhere anymore. There are only SS casing these days, in only one dimension and I don't know where to get them in the UK anyway...

(If you have no idea what I'm talking about you can see them page 14 of the Murray's catalog)
Posted By: Mark P

Re: Mast Sealing and Turtleing Prevention - 07/14/09 05:50 PM

I was out last Friday evening and had a capsize (what's new!!). I uncleat the main & traveller then the spi halyard cleat, after which I go up the hull towards the snuffer and pull the kite down and stuff it into the snuffer mouth by hand. I find this method both good for turning the bows and quick in getting the kite out of the water. When the boat is back upright I pull the retrieval line just to pull the spi down the snuffer. During the Club Race on Sunday I didn't capsize but just beat one of my close rivals on a Tiger by 3 secs.
I have also had a leaky mast and only found it whilst preparing it for a couple of coats of UV protective varnish which has surprisingly lasted two seasons.
Posted By: Timbo

Re: Mast Sealing and Turtleing Prevention - 07/14/09 06:30 PM

Thats a good idea Mark, I'll try that next time I crash, and I'm sure there will be a "next time" soon. ;^)
Posted By: ncik

Re: Mast Sealing and Turtleing Prevention - 07/14/09 11:17 PM

The point is that 10mins of water also takes a long time to get into the mast, so it must be sealed reasonably well already.

Righting technique will go a long way to preventing a turtle. Get onto the hull as early as possible, bring bow into the wind, then snuff the kite (most systems should enable this from under the tramp), re-right.

With this technique, the only part of the mast that needs to be sealed is from about the spreaders up, with higher priority the higher you go up the mast.
Posted By: JJD

Re: Mast Sealing and Turtleing Prevention - 07/15/09 12:58 AM






As always, the group is quick to provide well thought out advice. I appreciate everyone's response and will go out and reseal that mast. Good news is that I have a pool in my back yard big enough to float a sealed mast, or leak test one that isn't.
As far as the retrieval techniques are concerned, it's clear that I futzted around way too long getting to the bottom side and forward of the boat.
So advised, and with a properly sealed mast, I'll be back at it in no time.
Staying upright is indeed the best prevention, and I too have sailed with hulls full of water for ballast. That works, until they get full...
John
Posted By: CaptainKirt

Re: Mast Sealing and Turtleing Prevention - 07/19/09 07:59 PM

John-
Not sure about the Blades but on my Taipan (1997 model) I actually have an internal jib halyard so have a really nice, unsealable "hole" in the mast right below the hounds and another about a 20" up from the mast base. Apparently all the (old anyway?) Taipans just have the "top" of the mast sealed. There is a foam "plug" at the top and another foam "plug" that is just above the hounds- so the very top section of the mast is sealed- where there are no potential "leaks" anyway since no rivets in this section. The only time I turtled I was able to get the mast on it's side since the top was still sealed and the water could run out the "hole" at my jib halyard before I righted the boat the rest of the way. Might want to think about that option.

Kirt
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