1980 27' Minor Leakage at Deck/Hull Flange

[Todd]

I have a 1980 27'. In good shape overall but there is dampness/minor leakage during heavy rain. Water seeps in slightly along the seams at the deck rails or perhaps where rigging is mounted to the deck. All of these leak points are under the flange inside the cabin where the deck mounts to the hull. The moisture has seeped into the fabric/foam affixed to the side bolster of the hull and as a result, the fabric has mildewed. The bolts are all secure. I want to do two things without a lot of complexity:1) Apply a spray sealant under the flange all along the length of the boat to stop the leakage. I need a recommended brand and comments on whether this would work.2) Remove the old foam/fabric and relace with a new foam backing and use a spray adhesive to mount a new fabric on top of the new foam. Suggestions and also ideas where I could get the exact dimensions of the foam/fabric so I can have it cut to correct size prior to mounting. Thanks, Todd (704)965-8763

 

[TomH]

Rainwater leak

Todd,As a general rule of thumb sealant applied to the inside of any seam, thru bolt,or hardware has a slim chance of curing leaks for any length of time. My 27 leaked in the same area and I cleaned and wire brushed suspect screws and the inside edge of the toe rail and ran a bead of P U sealant around all of them. I got rid of 95% of the drips. My biggest leak ended up being the pump out port and it was not the flange that leaked it was the mounting screws.

 

[JC2]

Two chances

First, determine the source of the water. No fix is worth anything till you know for sure it's really going to be a fix.If it's through-deck hardware, remove the offending piece completely, dry and clean the hole, and rebed the hardware with 5200. Do NOT use silicone; it's worthless for this. I've peeled it too much of it off other people's boats, using my fingernails, to find moldy water lying under it. 5200 is made for this very job. $13.00 a tube. Trust it.If it's water coming under the flange at more than one or two places, well separated, it's probably the toerail. This is not as hard to fix as you'd think. Loosen all the bolts and carefully work it off the deck with a flat bar (use a block under it to save the deck). You don't have to take it all the way off-- just till the nuts are at the bottom of the bolts (3/8"?), letting you get the gunk out from beneath it cleanly. Then squeeze as much 5200 under it as you can stand. Any gaps in the bead will be leaks. You can clean up the overage much more easily than you can squirt more in later.Do not remove the toerail or any piece of rigging hardware with the rig tensioned and in place.As with ALL applications of 5200, do NOT torque up the bolts on the hardware immediately. Leave them snug (nutdriver tight, not with the rachet wrench). Two or three days later, give it hell. By that time (given warm weather) a true gasket with a chemical bond between the two faces will have formed and you'll have no leaks. That's how 5200 works.JC 2 (NOT employed by 3M Corp!)