crack/leak question

For issues common to different models of DaySailer.
Except Rigging and Sails.

Moderator: GreenLake

crack/leak question

Postby rickster » Mon Sep 03, 2018 8:29 pm

I recently acquired a 1980 DS II. After sailing it a couple hours for the first time, we left it docked overnight and the next morn there was a huge amount of water in the boat -- maybe 5 or 6" showing plus a ton in the bilge. The plugs were all present and looked OK. After getting it out and draining it (non trivial), it looks like there is a leak in the hull at the front of the centerboard. (Water was dripping from it.) There is also another crack in the hull (the other picture), though I don't know if it is actually a leak. Both cracks had been previously patched. See pictures below.

I'd appreciate any advice on how to fix this problem as well as answers to some specific questions:
- Is it really possible for that much water to come into the boat overnight through these cracks (which don't look all that big to me)? Or should I be looking somewhere else?
- Do I need to remove the centerboard to fix the crack in the opening to the centerboard slot? If so, any pointers on doing so? Seems like it might be difficult to patch up inside the slot. Hoping the crack doesn' t extend that far.
- General pointers to prep, patch material, etc. are welcome, though I can probably find them with some searching.

My goal is simply for the boat to be functional. Not so important that the patches look great.

Thanks.
Attachments
7594082128_IMG_1188.jpg
7594082128_IMG_1188.jpg (85.73 KiB) Viewed 1179 times
7527017280_IMG_1182.JPG
dripping crack
7527017280_IMG_1182.JPG (124.2 KiB) Viewed 1179 times
rickster
 
Posts: 2
Joined: Sun Sep 02, 2018 6:05 pm

Re: crack/leak question

Postby GreenLake » Tue Sep 04, 2018 2:51 am

Welcome to the forum.

I think the cracks, if they go through, are indeed a possible source of the water. If you want to be scientific about it, you could fill the boat with water when on the trailer and add food coloring. . . but you write "water was dripping from it" - if that was more water than just the few drops that would have fit the crack, I think you have your answer.

The fact that the cracks were "patched" also speaks to them having been a source of leaks. Just smeaing some goop over a thin crack like this will do nothing to fix it (as you are witnessing). However, a lasting repair is doable and not all that complex. (It helps if you can put your boat on its side with the help of 2-3 people - see copious discussions about turning over these boats, or just do it . . )

For DSII centerboard removal, see older posts in the "DSII only" section of the forum. Much repair stuff is general, but the DSII has some specific stuff about its CB, and that info we try to keep in that section. (You should be able to tell whether you need the board removed for access - not something we can diagnose for you from some photos).

Crack repair starts with grinding open the crack. Ideally with a 1:12 bevel (i.e. 6" wide for a crack that's 1/2" deep). Then you get fiberglass cloth and layer it with laminating epoxy. Pretty good instructions can be found on the West System or System Three websites. That type of repair is not only watertight, but restores any strength lost because of the crack.

Where the crack goes up into the CB well, you may run into some limitations as far as placing laminate. In those areas I would use 3M High Strength Marine Filler. It's a polyester-based paste that's thickened with glass fibers. It will fill gaps to 1/4" depth/width and is super strong. Normally we prefer epoxy because it bonds more strongly, but I've made good experiences with this stuff and would recommend it for hard to reach areas. (You still need to grind/scrape open any existing cracks).

On the flat parts of the hull, I would be very generous in the amount of laminate ground away, because the existence of the crack indicates that there's some damage to the laminate and that may well extend. Best to get anything that might be weakened out and replace with new layup.

The instructions will tell you this, but for epoxy, the key to success is careful and precise measurement and thorough mixing. (If you've never done any work with epoxy/fiberglass, or it's been a while, start with a flat piece that you lay up on a sheet of wax paper on your work bench. That sample, if it turns out well, can later be used as backing plate if you ever have a repair where there's an open hole, because laminate needs a surface to be applied to).

Note that you need to paint any epoxy for UV protection. If you drysail your boat, many paints will survive brief immersion, otherwise you'll need to get some stuff rated for below the water line.
~ green ~ lake ~ ~
GreenLake
 
Posts: 4980
Joined: Mon Jun 18, 2007 3:54 am

Re: crack/leak question

Postby rickster » Tue Sep 04, 2018 9:18 am

Thank you so much for the extensive answer!
Looks like a great learning experience for me:)
rickster
 
Posts: 2
Joined: Sun Sep 02, 2018 6:05 pm

Re: crack/leak question

Postby GreenLake » Tue Sep 04, 2018 11:17 am

Good luck and don't forget to post some updates.
~ green ~ lake ~ ~
GreenLake
 
Posts: 4980
Joined: Mon Jun 18, 2007 3:54 am


Return to Repair and Improvement

Who is online

Users browsing this forum: No registered users and 4 guests