Hobie Forums
http://www.hobie.com/forums/

Deck ports watertight?
http://www.hobie.com/forums/viewtopic.php?f=13&t=60869
Page 1 of 1

Author:  SabresfortheCup [ Mon Jun 26, 2017 12:28 pm ]
Post subject:  Deck ports watertight?

So I've been battling a minor hull leak for a few years, but haven't gone to the oft-mentioned bubble test... I'm just not crazy about putting pressure on my hulls, even a pound or so. I don't believe I have any leaks from the hull lips, rudder gudgeons, plugs or daggerboard trunks, as I've looked those over pretty well and the boat stays dry inside up until deck immersion or spray occurs (or after a good hard rain). I had suspected that the deck ports were only weathertight, rather than watertight. However, it recently occurred to me that the water could be leaking in around the edges of the deck port, rather than past the o-ring and through the threads. Anything in the fat bags usually gets pretty wet during a good sail. I imagine a bead of 5200 around the ports, inside the hulls and out might do the trick (rather than drilling out the rivets and caulking underneath. I know from experience that destroys the hull ports, too).

Can anyone else say for certain if their hull ports leak when screwed in, or if they stay bone dry?

Author:  srm [ Mon Jun 26, 2017 12:35 pm ]
Post subject:  Re: Deck ports watertight?

I can't see trying to put a bead around the outside of the lid working. I think you would need to pull the ports and apply the sealant between the flange and the deck. The ports can leak between the deck/flange or between the lid/flange.

I would just do a bubble test. It will tell you everything you need to know. A piece of hose jammed in the drain plug blown into with a few lung-fulls of air will pressurize the hull. Clamp off the hose and go around the boat with a squirt bottle of soapy water. I've done this plenty of times. You're much better off finding the leak rather than guessing.

sm

Author:  black4est [ Mon Jun 26, 2017 8:00 pm ]
Post subject:  Re: Deck ports watertight?

I'm about to install new port hole covers and curious where to put the silicon. Would I generously apply it around the circumference of the port hole housing, along the corner, and bolt holes?

Author:  srm [ Tue Jun 27, 2017 2:44 am ]
Post subject:  Re: Deck ports watertight?

Yes. Apply sealant to the flange and bolt holes. Then install the bolts and tighten with moderate torque, you should get some squeeze out around the flange. Wipe away excess, allow to cure, and you're done.

sm

Author:  SabresfortheCup [ Tue Jun 27, 2017 7:45 am ]
Post subject:  Re: Deck ports watertight?

A word of caution, when I installed mine 5 years ago, drilling out the old rivets was a pain... They spun and just burned a hole through the plastic. Once I got the port out, I realized that the fiberglass around the edges of the port was brittle. I put the new rivets in, but I'm sure that some of them didn't hold very well because there wasn't much for them to grip against. (Could also be the source of my leak) I applied the silicone liberally to the rivet holes and exposed fiberglass, as well as coating the underside of the flange. I put in 5" inspection ports in the aft deck a year later, and this time used 4000 sealant instead, which I think has sealed much better than the silicone. It's an adhesive, not just a sealant, and the 4000 variant is UV resistant as well. If you buy a tube of black pigment and mix it in before applying, you can even color-match it to your hull (my hobie, though "white" in color, is actually somewhat grey). I didn't even bother with rivets or screws, mostly because I bought flat deck ports and didn't want to warp them. (Purposely bought the flat ones, so I could use bottleports in them: http://www.bottleport.com/)

Five years later, my Hobie supplied white ABS plastic deck ports have yellowed horribly. The 5" grey polypropylene deck ports I installed in the sterns, on the other hand, still look grey. If I had to do it again, I'd buy the grey polypropylene deck ports and use 4000 to seal them, with machine screws, nuts and washers rather than rivets as a secondary, mechanical means of securing them to the deck.

*Edited to correct the type of 3M sealant used. 4000 sealant is the type I used, UV resistant for deck fittings. 5200 is more for sealing/adhering through-hull fittings.

Author:  srm [ Tue Jun 27, 2017 9:23 am ]
Post subject:  Re: Deck ports watertight?

Definitely use stainless screws with nuts and washers rather than rivets to install the ports. I'm sure Hobie only used rivets because they can be installed much more quickly in a factory setting. But the screws will give you better control over how much the flange is compressed against the deck. They also don't have the leak path that rivets do (rivets are hollow) and are easier to remove as you found out.

If you bugger up the holes in the deck taking out the rivets, just rotate the flange for the port a few degrees and drill fresh holes.

sm

Author:  OlderBowman [ Tue Jun 27, 2017 12:51 pm ]
Post subject:  Re: Deck ports watertight?

I also changed out my OEM pop-out ports years ago, using the screw in type.
As the others have said, bed the port ring in sealant at the flange, and use stainless hardware.

my slight deviation was to only snug up the machine screws until the sealant reached the outer edge of the ring. After it had fully cured I then tightened them a bit more.

if you find the old rivet spinning when you drill it out, as Sabre did. grab it from below with pliers to hold it still.

Page 1 of 1 All times are UTC - 8 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/