waste deck fitting leak

[paulga]

while working in the engine room, I spotted long time water stains on the port side forward bulkhead. it traces up along the pump up hose to the waste deck fitting. During the survey it was also reported moderately elevated moisture levels observed around the waste deck fitting on the portside deck.

I understand the complete repair requires replacing the wet wood. not sure if it's the o-ring on the cap or the sealant under the base that has broken down. I'm considering rebedding the fitting with new sealant, to stop the slow leak first. can someone describe the process to me?

 

[READY]

I don't think o-ring is a factor.it has to be the bedding. For a full and forever repair you would open up the core and replace where wet. Then seal the edges of the deck cut out with epoxy filler so no water can get in.

 

[Comodave]

If the O ring is leaking the water will just run into the holding tank. The bedding for the fitting is what you need to replace. For a permanent repair you will need to remove the wet core and replace it. But to stop the bleeding temporarily just rebed the deck fitting.

 

[mvweebles]

Deck fitting needs to be rebedded. I've been using Butyl tape instead of some flavor of caulking, though proper caulking works fine too.

I wouldn't worry about the elevated moisture level unless it shows signs of spreading or sponginess. Right now, as Comodave said. Important part is to stop new moisture from getting under the fitting, especially with winter will frost heaving can do some outsize damage.

Peter

 

[Bacchus]

I've used a couple different butyl tapes but Bed-It Tape sold by CMS a Commercial Member here is the best. He has a good How To article posted with some worthwhile tips.
https://marinehowto.com/bed-it-tape/

 

[paulga]

Bed-It tape is also available from amazon

I have some questions on using this tape:

in step 1:

if the screw holes under the waste deck plate was not beveled, is it necessary to countersink it using a Countersink Bit? the mentioned size is 5/8". how to decide the proper size based on the screws?

how to tell if the existing sealant is silicone? if so what abrasive paper to use for removal?

in step 7:

it requires a waiting period between sequential small tightening actions. do people really span the tightening work over 2 to 3 days? or a heat gun can speed this up to within one hour?

the attached photo is a screenshot of a diesel heater exhaust lead through installation video -- the worker is applying a white caulk around the through hull and over the screw holes for sealing. Can Bed-It tape be used alternatively?

I've used a couple different butyl tapes but Bed-It Tape sold by CMS a Commercial Member here is the best. He has a good How To article posted with some worthwhile tips.
https://marinehowto.com/bed-it-tape/

 

[Comodave]

Bed-It tape is also available from amazon

I have some questions on using this tape:

in step 1:

if the screw holes under the waste deck plate was not beveled, is it necessary to countersink it using a Countersink Bit? the mentioned size is 5/8". how to decide the proper size based on the screws?

how to tell if the existing sealant is silicone? if so what abrasive paper to use for removal?

in step 7:

it requires a waiting period between sequential small tightening actions. do people really span the tightening work over 2 to 3 days? or a heat gun can speed this up to within one hour?

the attached photo is a screenshot of a diesel heater exhaust lead through installation video -- the worker is applying a white caulk around the through hull and over the screw holes for sealing. Can Bed-It tape be used alternatively?

View attachment 144091

Go to marinehowto.com and read his article about how to bed deck fittings. I always countersink any hole in the deck in order to form an O ring of whatever sealant I am using, whether butyl or caulk.

I take 3 days in tightening butyl. Tightern it once each day.

If the previous sealant was silicone I scrape as much as I can with a sharpened putty knife. Then use some sandpaper to finish cleaning it off. And then never use silicone again…

 

[Bacchus]

Jay
After scraping with putty knife, razor blad etc to get as much as possible off then sand once you think it's all off... it really isn't.
I've had hood success using a fine grit wet/dry -say 400. I've also used masking tape around the area being cleaned to avoid sanding too far but if you do and scratches are visible just go to finer wet/dry to smooth it out. You can get 1,000, 2000 & 4000 grit that leaves a very smooth surface w/o scratches.
Yes I beveled all holes for the added seal. I generally use a counter sink tool and it works well. I countersink about as much as you would for a flat or oval head screw the size of the hole. If pressed for time I guess a hair dryer (or heat gun on low & used cautiously),would help speed things up but it's more than just the surface that needs to heat up. It really takes the fitting and underlying fiberglass to both warm &;allow the butyl to ooze out. I would ny worry if it takes longer, Ex: if you leave boat and come back a week later... just retighten and wait again. You can get a good initial seal.
The CMS website is well done and helpful.

 

[paulga]

I read both articles. i guess you are referring to the one that makes a larger hole and pots the hole with thickened epoxy. so is the Bed-It tape an alternative way? if you use this tape, there is no need to enlarge the hole and fill with the West system 610?

Go to marinehowto.com and read his article about how to bed deck fittings. I always countersink any hole in the deck in order to form an O ring of whatever sealant I am using, whether butyl or caulk.

I take 3 days in tightening butyl. Tightern it once each day.

If the previous sealant was silicone I scrape as much as I can with a sharpened putty knife. Then use some sandpaper to finish cleaning it off. And then never use silicone again…

 

[paulga]

how do you tell is the existing caulk is silicone? or just use acetone, sealant knife and sanding paper to clean after countersinking?

Jay
After scraping with putty knife, razor blad etc to get as much as possible off then sand once you think it's all off... it really isn't.
I've had hood success using a fine grit wet/dry -say 400. I've also used masking tape around the area being cleaned to avoid sanding too far but if you do and scratches are visible just go to finer wet/dry to smooth it out. You can get 1,000, 2000 & 4000 grit that leaves a very smooth surface w/o scratches.
Yes I beveled all holes for the added seal. I generally use a counter sink tool and it works well. I countersink about as much as you would for a flat or oval head screw the size of the hole. If pressed for time I guess a hair dryer (or heat gun on low & used cautiously),would help speed things up but it's more than just the surface that needs to heat up. It really takes the fitting and underlying fiberglass to both warm &;allow the butyl to ooze out. I would ny worry if it takes longer, Ex: if you leave boat and come back a week later... just retighten and wait again. You can get a good initial seal.
The CMS website is well done and helpful.

 

[paulga]

What tape would you use to temporarily seal around the deck plate? I want to take the plate off to check hole size, but may not be able to seal it properly before the rain.

 

[Comodave]

Gorilla tape, maybe. Duct tape if temporary.

 

[Bacchus]

I dont know of a way to test or tell for sure it's silicone. Feel,mappearance, texture are indicators IMO. Silicone remains rubbery, peels off in sheets or strips where other caulks are more putty like, if that makes any sense.

I've had good luck using a metallic foil tape for sealing on boats both temporary and more permanent. Sun / UV has little affect where it degrades other tapes.
If any question assumingnit was silicone and being extra careful w prep will never hurt.

 

[paulga]

Is there a target torque on each day?
would it be rain proof by the end of the first day?

Go to marinehowto.com and read his article about how to bed deck fittings. I always countersink any hole in the deck in order to form an O ring of whatever sealant I am using, whether butyl or caulk.

I take 3 days in tightening butyl. Tightern it once each day.

If the previous sealant was silicone I scrape as much as I can with a sharpened putty knife. Then use some sandpaper to finish cleaning it off. And then never use silicone again…

 

[Comodave]

I don’t use a particular torque, just tighten it until it gets hard to do. Then wait a day and give it a bit more and you should see some butyl squeeze out. By the 3rd time it should be tight and squeezed out well unless it is really cold out. At the end of the first time it should be fairly water tight if not inundated with water.

 

[paulga]

the 3 screws are Ph #2, they felt like not tightened at all. but after taking off the screws, the round plate does not even wiggle a bit. so I had to put the screws back and tighten the cap.


the screws' holes felt soft as mud, I didn't use force but after reinstalling the screws their head looked like lower than in the beginning.



is it just a plate that can be easily rebeded using Bed-It tape? or is the plate part of a mid sized structure or connected with the hose?

 

[Bmarler]

i think it's amazing to most of us here that you've never seen a deck fitting that's not installed.
here's a link to one: https://www.westmarine.com/west-mar...C6qLgXKA5LjWep_jpWin-PK0FlODuVYsaAqbeEALw_wcB

as you can see, the hose attaches directly to it. if there's no slack in the hose, and there's still a certain amount of sealant holding it down, you won't be able to wiggle it. it'll fight you even when the hose is removed.
it's a can of worms every time you go at this stuff. just getting the hose off is tough, and you'll probably ruin the end of the hose that's just barely long enough to begin with. then you'll need to route a new hose, but it's behind some chunk of cabinetry or something. on and on...

 

[paulga]

Thanks for the link

no wonder a contractor told me two months ago he would need to remove the kitchen closet to be able to check the portside deck fitting. maybe that's the only operation access to the hose below the plate

if the previous sealant is 5200, it probably will have to stay the way it is now. if not, is it possible to pry with a sharp putty knife and lift the the plate just a tiny bit say 2cm to apply the tape? just 2cm should not do any harm to the hose

i think it's amazing to most of us here that you've never seen a deck fitting that's not installed.
here's a link to one: https://www.westmarine.com/west-mar...C6qLgXKA5LjWep_jpWin-PK0FlODuVYsaAqbeEALw_wcB

as you can see, the hose attaches directly to it. if there's no slack in the hose, and there's still a certain amount of sealant holding it down, you won't be able to wiggle it. it'll fight you even when the hose is removed.
it's a can of worms every time you go at this stuff. just getting the hose off is tough, and you'll probably ruin the end of the hose that's just barely long enough to begin with. then you'll need to route a new hose, but it's behind some chunk of cabinetry or something. on and on...

 

[Comodave]

Ok, if it is attached with screws and not through bolted then I wouldn’t use butyl tape to install it. The screws will not generate enough clamping force to properly squeeze the butyl. Instead use a quality caulk like Sika 291 to bed it. Do not use 5200! If the screws are in soft material then you will need to fix the deck where the screws go. You will at a minimum need to reef out the bad core and fill the hole with thickened epoxy and then drill holes for the screws in the epoxy.

To get the fitting off the deck;
Remove the screws
Try to gently pry the fitting up
If it doesn’t come up then try heating the fitting with a heat gun and pry
You can sharpen a putty knife and use that to cut the caulk

It will eventually come off. Just keep at it.

 

[paulga]

I just got a bit more comfortable thinking about glasswork. The bare minimum still requires getting the awlgrip off and cutting the top layer open, so why not replace all wet core. I may attempt working on glass next summer if I'm able to get down to it.

I will seal around the waste plate using the tape until I have time to get down to it.

I usually wonder how many people would really seal all deck hardware this way as introduced on marinehowto. To me, using bed-it tape is good enough (this is for a thought deck bolt, not a screw)

Ok, if it is attached with screws and not through bolted then I wouldn’t use butyl tape to install it. The screws will not generate enough clamping force to properly squeeze the butyl. Instead use a quality caulk like Sika 291 to bed it. Do not use 5200! If the screws are in soft material then you will need to fix the deck where the screws go. You will at a minimum need to reef out the bad core and fill the hole with thickened epoxy and then drill holes for the screws in the epoxy.

To get the fitting off the deck;
Remove the screws
Try to gently pry the fitting up
If it doesn’t come up then try heating the fitting with a heat gun and pry
You can sharpen a putty knife and use that to cut the caulk

It will eventually come off. Just keep at it.

 

[mvweebles]

If the screws are in soft material then you will need to fix the deck where the screws go. You will at a minimum need to reef out the bad core and fill the hole with thickened epoxy and then drill holes for the screws in the epoxy.

When I read the OPs post, I thought the screws might be stripped - maybe a larger screw was originally fit or a screw-gun over-tightened the screws and made the hole too big.

Comodave -cover your eyes here, but if it's a stripped hole, fill the hole with a short length of epoxy-coated (wet) toothpick or bamboo skewer, just long enough so it's flush with the surface. Won't fill the hole completely, but when you screw-in the fastener, will provide enough clutter in the hole so the screw will bite.

If the core is super soft, probably need to think about repairing it as Comodave suggests. But the toothpick filler will get you through as long as you can get some bedding beneath the flange of the deck fitting.

Good luck -

Peter

 

[BruceK]

Tapered end of a wooden chopstick works as a screwhole saver too.

 

[paulga]

Fastener means the cap, correct? The base holds really stable when I tightened the cap. Given the screw holes are so weak, it must be the existing sealant providing the strength.

I don't know if the screws holes are stripped or not. It's super soft as if can be easily damaged.

The waste tank can be pumped out from either side so the portside waste fitting can be decommissioned, though it is much more labor intensive than simply cover with tapes.

When I read the OPs post, I thought the screws might be stripped - maybe a larger screw was originally fit or a screw-gun over-tightened the screws and made the hole too big.

Comodave -cover your eyes here, but if it's a stripped hole, fill the hole with a short length of epoxy-coated (wet) toothpick or bamboo skewer, just long enough so it's flush with the surface. Won't fill the hole completely, but when you screw-in the fastener, will provide enough clutter in the hole so the screw will bite.

If the core is super soft, probably need to think about repairing it as Comodave suggests. But the toothpick filler will get you through as long as you can get some bedding beneath the flange of the deck fitting.

Good luck -

Peter

 

[Comodave]

I just got a bit more comfortable thinking about glasswork. The bare minimum still requires getting the awlgrip off and cutting the top layer open, so why not replace all wet core. I may attempt working on glass next summer if I'm able to get down to it.

I will seal around the waste plate using the tape until I have time to get down to it.

I usually wonder how many people would really seal all deck hardware this way as introduced on marinehowto. To me, using bed-it tape is good enough (this is for a thought deck bolt, not a screw)

View attachment 144252

The people that want no leaks and to keep the deck core dry do that process. You can shortcut the process but you will likely end up with leaks and/or wet core or both. It is a lot or work to do it right but that is what it takes.

 

[mvweebles]

The people that want no leaks and to keep the deck core dry do that process. You can shortcut the process but you will likely end up with leaks and/or wet core or both. It is a lot or work to do it right but that is what it takes.

For the record, I gave you fair warning to close your eyes......:

.....Comodave -cover your eyes here, but if it's a stripped hole, fill the hole with a short length of epoxy-coated (wet) toothpick or bamboo skewer, just long enough so it's flush with the surface.

Peter

 

[paulga]

do you do both things shown below for bedding hardware on the deck, or is picture #1 (using dremel 654 to make a small cavity and pore epoxy) optional?

The people that want no leaks and to keep the deck core dry do that process. You can shortcut the process but you will likely end up with leaks and/or wet core or both. It is a lot or work to do it right but that is what it takes.

 

[Comodave]

That is what I do. Before I had the Dremel bits I used an allen wrench with the short end cyt down to about 3/8” and chucked it into a drill. But the Dremel bit works much better and easier and quicker. Then fill with thickened epoxy and drill the proper size hole after the epoxy has setup.

 

[paulga]

Thanks Dave. This has solved one of my confusions.

That is what I do. Before I had the Dremel bits I used an allen wrench with the short end cyt down to about 3/8” and chucked it into a drill. But the Dremel bit works much better and easier and quicker. Then fill with thickened epoxy and drill the proper size hole after the epoxy has setup.