Missing Flanges on Thru-Hull Fittings- 1988 Seafarer

[frank1492]

I am ready to address what I am told are potential "sinkers" though 3 of the 4 plastic flanges have been missing for several seasons now.
Grady tells me marinas do new thru-hull fittings "all the time," though they said it wasn't easy.
If someone has done this, could you please tell me exactly what I am in for, and how to access these? In the event it is too difficult I have a plan to machine some new fittings (with flanges) to precisely slip into the remains of the old flanges and secure with epoxy.
Help much appreciated!
Frank

 

[Curmudgeon]

Locate your fittings, locate nearby access to the space, decide if you can handle it. If you can't, seek professional assistance.

Your new flange may fit 'precisely' into the remains of the old fitting, and be secured with epoxy, but your base is a plastic fitting that has already broken once. Have your insurance policy up to date and be sure you have more than minimum required emergency equipment. As you said, broken thru hulls are 'sinkers', and you're only patching where fixing is the smart move ...
:sorry

 

[Clockwork]

get them fixed. boats go down all the time on account of poorly maintained and/or designed thru hulls. its not easy though. ive done a few including the rear scuppers on my grady. each time i had to use a hammer to break off the outer flange and tap it inward because they use 5200 or the equivalent sealant adhesive to intall them and that stuff is strong.

then yolu have to clean off all the old sealant out of the hole. i used a wire wheel on a drill motor. then you slather then new ones (i recommend stainless) with 3M 5200 sealant adhesive andput it in, tighten the nut, let it cure and then put on the hose and make damn sure the hose is in good shape.

if you have any water seepage, which is common in my experience, let it sit until it stops and drys out because you cant seal over a wet surface. give yourself plenty of time.

the fishbox drains on my overnighter are just barely accessible.

 

[Pez Vela]

Although I agree with Curmudgeon 100%, I have been faced with an inaccessible location (even with the thought of "creating" access) where I resorted to your "plan." I used 5200 to adhere the smaller (diameter) stem of the new mushroom inside of the broken through hull. Try to get the longest stem you can on the new piece if you have to do this, and (like you said) sand it down as needed to get a near perfect snug fit. I did this on my trailer boat, but if I kept my boat in the water full time, I'd be much less likely to take the "easy" way out. I'm happy to report, so far, so good.

 

[JeffN]

Replace them! It is way past time for this to be done. If you can get get to the back of each thru hull the replacement job is not all that hard. Look it over, be honest with your skills and if you are a little handy and feel up to it have at it. If not have a professional do it. I found on my model Grady, that is about five years older than yours, I was able to access the rear of all the fittings. The most difficult thru hull replacement on my boat was the drain for the fishbox in the deck between the helm seats. The tru hull was right at the water line so it was an important one. I replaced the fitting and the drain line. Not easy but doable. The other hard project was replacing the fuel vent and fill line. Both of these replacements appeared to be inexcessable at first but with a bit of exploring I was able to expose enough of the lines and rear of the fittings to get the job done. The thru hull at the water line was plastic or nylon like yours but I replaced with bronze.

 

[frank1492]

Thanks all for your excellent comments. My boat is at a distant location at the moment and still covered for the winter so have not examined access to the thru-hulls from the inside. As I said, Grady tells me access is possible (but not easy) on the Seafarer, which I assume means no cutting of fiberglass will have to be done.
Clearly the insert method is not as good as the replacement method. My plan was to use bronze thru-hulls (3/4" Grocos with pipe threads can easily be machined down to the required OD, still maintaining adequate wall thickness.) These would be cut to the required length and secured with 5200. I can't see much risk there assuming the remaining plastic isn't stressed, but I agree this doesn't address hose issues. I think the remnants of the thru-hull aren't likely to be weakened because I should think the deterioration of the flanges would be largely due to exposure to sunlight.
Any other thoughts would be most welcomed. I'll be making a decision shortly.

 

[JeffN]

thickness.) These would be cut to the required length and secured with 5200. I can't see much risk there assuming the remaining plastic isn't stressed, but I agree this doesn't address hose issues. I think the remnants of the thru-hull aren't likely to be weakened because I should think the deterioration of the flanges would be largely due to exposure to sunlight.
Any other thoughts would be most welcomed. I'll be making a decision shortly.

Your point about the interior plastic is a good one. On mine after I had figured out that I could replace the fishbox drain thru hull I just decided it was a go and grabbed the outer portion of the fitting with a pair of channel locks and the fitting snapped right off. VERY little twisting force was required. Upon examination I found that the fitting was cracked about half way around right behind the outside flange. I found out when I got into it that the fitting is intalled right at the area where the sides of the hull transition to the bottom, so while the outside of the hull was flat on the inside the hull was thicker on the bottom than on the top of the fitting. The threaded ring retainer on the inside was cross threaded from the factory and had caused the stress crack in the fitting I think. I feel a metal thru hull fitting would do better in that situation. The hoses I replaced were not in bad shape considering they were pushing 30 years old. The showed age but the hoses did not come out in pieces.

 

[NIGHTIDES]

Keep in mind most guys do not change out the hoses since they are generally not 100% accessible. But the thru hull should be done the correct way. We all moan about what a pain it is but once replaced with new metal fittings, you're done..period.!

Good luck with it.

 

[Pete1313]

Replace hoses too...or at least check them. My new to me 1997 Voyager aft bilge pump thru hull broke out when I yanked on it (not very hard). Then, i bent the bilge hose and after one back and forth it disintegrated in my hands. After that, I yanked on every thru hull I could get to, and replaced any worn out one with bronze (couldn't get stainless...long story). Anyhow, these are vital and the thru hull requires a tight fit from behind to remain water tight, even with 5200.....just epoxying the new flange in will not ensure that the hose will not come loose from the inside. Most of these are at teh waterline and the ones that aren't are for the bilge pump (e.g. if it breaks your bilge pump is pumping water back into the bilge at 1500 gph).

They are a PAIN IN THE ASS and you need to be a double jointed orangutan to reach them all.......but it is worth it once you're done.

My .02.....

 

[Grog]

I replaced my old plastic ones with SS (above water-line) and bronze (below/at waterline). The metal ones were basically the same diameter as the plastic ones. Seal them with 5200 (if you don't plan on removing them in the future) or 4000 (not a permanent bond) not epoxy it has to have a little give. If you haven't done the hoses do them too, access holes may have to be cut. I don't think it's a fun job on any model and plan on getting cuts and bruises.

 

[JUMPNJACK]

frank1492, I read your post a couple of nights ago and should have posted a reply immediately for safety's sake. Apparently you have already used up several seasons of luck! Those below or even slightly above the waterline thru hulls are nothing to fool around with. Those damaged flangeless thru hulls are dangerous. I replaced all the thru hulls on my '87 Sailfish about this time last year. A couple of them disintegrated while I was removing them and they still had the flanges intact. All the sealant was located on the outside of the hull and none was used on the inside. I would say the only thing keeping yours in place are some stiff hoses. It is true that when you get thru replacing them you will look like you have been sorting bobcats as they are fairly challenging to access. frank1492 replace those thruhulls before you sink your boat in the ocean blue! 8)

Ken

 

[JUMPNJACK]

"JeffN"The most difficult thru hull replacement on my boat was the drain for the fishbox in the deck between the helm seats.

Jeff, my Sailfish as I mentioned last year is the younger sister of your Kingfish. I am thinking that the layouts of the livewell/fishboxes are nearly identical. That was the one fitting that was the most difficult by far. I could just barely access the back of that fitting with the tips of a couple of fingers. Replacing the hose was far more difficult than the fitting. I think the boat may have been actually constructed around that piece of hose! I had to add a deckplate at the rear of the livewell just to access that end of the hose. Hope you and the Kingfish are doing well! 8)

Ken

 

[frank1492]

Thanks all for your continuing help!
I should be visiting my 1988 Grady Seafarer next week, but here's another "preview" question. If the hoses can't be accessed easily, will I at least be able to *see* all four points where they are attached to the thru-hulls from inside the boat?
Thanks.
Frank

 

[JeffN]

Jeff, my Sailfish as I mentioned last year is the younger sister of your Kingfish. I am thinking that the layouts of the livewell/fishboxes are nearly identical. That was the one fitting that was the most difficult by far. I could just barely access the back of that fitting with the tips of a couple of fingers. Replacing the hose was far more difficult than the fitting. I think the boat may have been actually constructed around that piece of hose! I had to add a deckplate at the rear of the livewell just to access that end of the hose. Hope you and the Kingfish are doing well! 8)

Ken

Doing well thanks Jack. Just about ready to tackle a few projects on my boat now that the weather is warming up. Going to redo the graphics this seaon and replace the engine instruments and instrument panel. We will see how that goes. That hose was a son of a gun to replace. I accessed the fitting on the bottom of the fish box by placing a jack on plywood on top of the port bunk and jacking the deck up just enough to be able to remove the plywood panel that forms the bulkhead of the berth against the fish box. Once removed I was able to get to that fitting. On the starbord side I was able to remove that small shelf like structure at the rear of storage area behind the head under the helm seat. The tubing ran behind that. That space is tough to work in, I was back in it last year to replace the fuel fill and tank vent line. On your boat was there a small beckson port to access the back of the thru hull? There was on on my boat but I sort of rememeber cutting one in somewhere many years ago maybe that was the one. I can't remember why I needed to get in there but it did come in handy for the fitting replacement, perhaps it was stock. Enjoy the boat this season Jack.

 

[JUMPNJACK]

All right JeffN, always a pleasure to talk with you! Yes sir, the small access plate was installed at the factory. I think that it must have been intended for a visual inspection of the back side of the thru hull because you sure as heck could do little more than look at it. Was it you who made mention of the double jointed orangutan? I actually cut a 5" x 10" access hole starting at the beckson plate. I had to round off a few sharp edges back in there behind the knee wall because that was where those bobcats were living. After I finished the installations in that "Blackhole of Calcutta" I put the cutout section back in place. The drain on my live well is on the starboard side and towards the rear of the well and not reachable from the port bunk area. I could have removed the head enclosure and the main bulkhead for possible access. I opted to cut in the other beckson plate for that which made it fairly easy. I hope that you also enjoy you boat this season. I notice that you and I always seem to surface around the post around these older boats. Take care buddy! 8)

Ken