Fiberglass and acid

[66luders]

I dont know if other allied boats are similar but my luder's 33 has a drain on either side of the cockpit (drains from around the lazerett lids and the deck). they drain into the fiberglass reinforcement channels that are part of the hull. how can i access the actual thruhull if it is under the fiberglass. I was working on making a better battery box and i heard a clicking noise near to the feinforcement channel... i also noticed a rotten smell right next to where i heard that clicking. I almost thought that something was living in there. The previous owner had drilled a drain hole in the battery box which would have leaked right in that area (and i believe they did overflow). I thought that polyester was resistant to sulfuric acid... but maybe some of the acid got absorbed by the plywood of the battery platform.

[sailingdog]

Hmm... sounds like a bad design. I don't know what to say about the through-hull, but if you had some photos it would help... since I don't really know what you mean by fiberglass reinforcement channels.

As for the battery box... they're supposed to contain the acid, and he really shouldn't have drilled a hole in the bottom... it defeats one of the primary purposes of the battery box.

Some resins are fairly acid resistant, others not so much. The rotten smell is probably due to the sulphur, from the acid. If the battery platform was made properly, it should have been coated with epoxy, to prevent it from absorbing moisture and rotting. Apparently, that isn't the case here.

[66luders]

I didn't take pictures today... maybe tomorrow. I guess I could have described things more accurately. I was told that the hull reinforcement channels are glass laid ontop of carpet roles (the cardboard tube from a carpet) so they take the shape of a half round. There are two running from the stearn, one on each side of the center line of the hull... they terminate when they reach the cabin bulkhead (at which point they are below the water line) There are two of the same hull reinforcment channels that run down the sides of the hull and intersect the first two. It is these two side ones which have a tube connecting to the drain from the side decks and the lazerett covers. I will take a picture.
As far as the fiberglass battery boxes... I was dumbfounded when I found the single hole drilled in one corner of each box. It looked intentional. I epoxied them closed as soon as I found them.

The original battery platform looke like it may have been sealed with glass but it had been modified, leaving exposed plywood.

Thanks for the feedback Sailingdog, I will take pictures because I want to figure out why the boat has this design feature.

[sailingdog]

Glad to help... be interested in seeing the construction you're talking about.

[66luders]

Here are a few images the drain build into the hull reinforcement...
BTW... the whole boat is under construction. I was going to work on making a secure battery box but that is now on hold until I figure out if the drain is SAT. Everything is unfinished.

[sailingdog]

That looks like a hose that been fiberglassed into the hull, rather than just a tube. That is a fairly typical way to make floors or stringers to reinforce the hull. However, I generally don't see them used as drain lines. Where does the end at the bottom of the last photo go to??

[SimonV]

WOW that looks scary, does the cockpit drain into the bilge??????

[sailingdog]

I doubt that it just empties into bilge... that would be both really dangerous and really dumb. Probably goes to a through hull or a pipe glassed through the hull. I've seen it done both ways.

[Idiens]

Looks like an attempt to build a cockpit drain without using a sea ****.

[TrueBlue]

If cockpit water drains via a through-hull fitting, of course the height of standing water remaining in the tube/hose will always be at the waterline outside of the hull - which is probably aligned with the top of the glassed tube shown in pic 1.

Not unusual to see this setup and no different than sinks situated above the waterline, draining via a hose to through-hulls. We have four in our boat plumbed this way.

My only reservation would be in the absence of a seacock at the through-hull fitting, there is no means of cutting off water intrusion in the event of a ruptured tube or hose.