Garboard Drain Fitting repair

[GaylesFaerie]

Hi, I had my first haul out for my 2012 R27 a couple of weeks ago. In anticipation of cleaning out the bilge in Spring I thought I would check out the keel drain plug to flush everything out. I put a 1/2 inch crescent wrench on it and before I could apply any significant pressure I noticed the entire round flange/fitting started to rotate about 1/16 of an inch back and forth. My first thought was "Wow, I just saved the boat with a 30 second check up!". Then reality set in...

Just thinking out loud: I've only seen this kind of behavior with wood that is beginning to rot out and screws that have consequently lost their bite. I don't see any bolt heads in the bilge where the drain is so I assume its screws (bad form). Is the keel basically wood with fiberglass overlay? Is the keel all fiberglass? Maybe the drain plug post hit something in the water that jarred it loose? Is this a simple rip and replace or do I have a bigger problem?

Also, I've not had any issues with the bilge other than an occasional drip from the stuffing box while docked, so I don't think there is any unwanted intrusion of seawater into the bilge... yet.

Open to any and all comments and advice. Thanks, GF

 

[BB marine]

I will describe the installation of the Garboard drain fitting in my C26. The keel is fiberglass where the drain is installed, The drain fitting is installed with 3 #10 machine screws made of 304 SS. There are nuts fastening the fitting in the bilge area The garboard drain fitting has one screw and nut fastener that is attached to a ground ( bonding wire)

What I believe happened to your drain fitting is the fasteners corroded. The unfortunate component of using 304 SS fasteners under water is they disappear over time. I'm not sure about the quality of the fasteners used in the Fluid Motion production line. I have had my boat is salt water for only a month and pulled it out of the water and noticed all the fasteners at the swim platform bleeding rust. I was amazed at how much rust was forming around the fasteners and washers. There was a 28 Cutwater that was docked next to me for a few days. He rack stores his boat at Barber Marine near Orange Beach. He told me the stainless is a full time job trying to keep the rust off. 304 SS is ok on the top side for fasteners but 316SS should be used underwater fasteners.

 

[ALICE J]

When I bought my 2011 R27 in 2014, I began grounding all exposed underwater metals. I drilled a hole in the garboard plug through the hull into the bilge, then fastened a bonding wire to the main bonding strip. I did the same with the stainless steel struts on the swim platform bonding them to the common bonding ground, additionally, I placed zincs on the ss struts. I also connected a bonding wire to the trim tabs in addition to the zincs mounted on trim planes. The thru-hulls were already grounded, I just cleaned them. Additionally, I put a shaft wiper on the shaft and connected a bonding wire. I have had a qualified marine electrician check for electrical leakage and found it to be acceptable, But I find that I am replacing zincs about 6-8 months, including the engine and thruster anodes even though I hang an anode over the side connected to the negative battery terminal. I don't hang out docks, mostly anchor out or on my trailer.

 

[knotflying]

I had to replace mine. It was never bonded and attached with stainless wood screws I removed it and bought a new bronze assembly. I through bolted it using bronze machine screws and 4200. On the one thru bolt I made it longer and attached a bonding wire to it. I also use anti-seize on the plug and twice a year I remove it, clean the threads, apply anti-seize and then reinstall. So far good.

 

[GaylesFaerie]

Thanks all for your replies - very helpful. I went down and removed the garboard drain today.

Drain removed with caulk still in place: https://photos.app.goo.gl/Y56z6Vw6GUaXzXf99

BB called it right. The screws corroded and the bronze fitting was beginning to get pitted resulting the loosely goosely rotation I saw.

Fitting and screws showing corrosion: https://photos.app.goo.gl/G2QQzmXCEVjwe29T8

If you look closely you can even see the bonding connection to the stainless steel skid plate on the keel right behind the thru hole.

Cleaned thru hole with skid plate bonding visible: https://photos.app.goo.gl/yEZYgrvyecTni58E8

I wonder why the factory doesn't bond the garboard fitting right there? Seems real simple.

I think I'll go the Knotflying solution. I've found two options I like at Sea Dog:

Bronze: https://sea-dog.com/groups/2872-garboard-drain-plug
SS (316): https://sea-dog.com/groups/2879-captive ... drain-plug

The captive SS looks pretty neat but it intrudes pretty far into the bilge and may actually interfere with the bilge pump housing and hose on my 27, so I'm thinking go with the simple bronze fitting and exercise each season. Knotflying, where did you get the bronze bolts? Sea Dog doesn't seem to have any. GF

 

[Brian B]

While you are at it check the bolts on the skid plate. My plate was not bonded which caused bolt corrosion issues. Refer to my thread from a couple of years ago. viewtopic.php?f=5&t=10992&hilit=+Skid

 

[knotflying]

Can't remember where I got the screws, but a search on the internet will give you plenty of choices.

 

[Brian John]

Garboard?

Garboard - Oxford Reference
Nov 30, 2022The first plank on the outer hull of a wooden vessel next to the keel, into which it is rabbeted. It runs from the stem to the sternpost and is similarly rabbeted into those timbers. The term was also used in wooden ships to describe the first seam nearest the keel,