Almost sunk my boat

[sunbyrned]

I have the same boat as Jullian in post #64. I think the scupper port is AT the waterline, maybe slightly below? The standard mentioned by SBrown might be why our boats have plastic scuppers. With that being said, they could have used one of the other materials he listed as acceptable. The standard is there for a reason, what is the risk of stainless steel vs our OEM plastic scuppers?

That, I do not know. There a lot of people who have switched over to stainless though. I don’t recall reading about anyone regretting that move.

 

[Julian]

That, I do not know. There a lot of people who have switched over to stainless though. I don’t recall reading about anyone regretting that move.

No one will regret making the switch to SS, they'll only regret not switching. If you've even opened the bilge and looked at that hose, it hangs on that scupper fitting. When you go over wakes/waves/trailering, that hose bounces up and down.....constantly flexing the scupper "pipe". It is that constant flexing that will eventually have it snap off, leaving an 1.5" hole in your boat.

I describe all of this in this video on the topic:

 

[Sbrown]

I don't bring this up to be a prick or be negative or even just different. I bring it up because its important knowledge to have.

Stainless steel is probably a step up in reliability from the stock plastic ones (which should be Marelon). However its not without it faults, stainless steel under certain circumstances is subject to a process called crevice corrosion. A stainless steel fitting installed below the waterl Iine duplicates these condition almost perfectly. Keeping the boat on a trailer is not a good preventative. You can google "crevice corrosion" for yourself, there is a ton of information about it. It can happen with stainless steel anywhere it has contact with with another metal or non-metal object and requires only miniscule amounts of moisture.

My only points in bringing this up time and again is simply because installing a SS scupper is not a once and done for all time repair, the scupper will still require regular replacement.

I would also be concerned if my boat sinks because of a scupper failure, due to an incorrect part for the application, installed by me, against all published standards, will my insurance still cover me? Its worth checking in to.

I'll stay with the factory Marelon one and expect to inspect and/or replace it as part of regular maintence, or I'll use the appropriate bronze fitting, if I can find one, which will still require regular inspection, but at least I should be able to see any corrosion if it is happening.

 

[RobbieO]

I don't bring this up to be a prick or be negative or even just different. I bring it up because its important knowledge to have.

Stainless steel is probably a step up in reliability from the stock plastic ones (which should be Marelon). However its not without it faults, stainless steel under certain circumstances is subject to a process called crevice corrosion. A stainless steel fitting installed below the waterl Iine duplicates these condition almost perfectly. Keeping the boat on a trailer is not a good preventative. You can google "crevice corrosion" for yourself, there is a ton of information about it. It can happen with stainless steel anywhere it has contact with with another metal or non-metal object and requires only miniscule amounts of moisture.

My only points in bringing this up time and again is simply because installing a SS scupper is not a once and done for all time repair, the scupper will still require regular replacement.

I would also be concerned if my boat sinks because of a scupper failure, due to an incorrect part for the application, installed by me, against all published standards, will my insurance still cover me? Its worth checking in to.

I'll stay with the factory Marelon one and expect to inspect and/or replace it as part of regular maintence, or I'll use the appropriate bronze fitting, if I can find one, which will still require regular inspection, but at least I should be able to see any corrosion if it is happening.

So educating myself on crevice corrosion. Since this corrosion is caused by gaps in the mating surfaces, wouldn't using 5200 solve that issue? Also, it seems using non-absorbing teflon gaskets/sealers would also help.

 

[Julian]

I don't bring this up to be a prick or be negative or even just different. I bring it up because its important knowledge to have.

Stainless steel is probably a step up in reliability from the stock plastic ones (which should be Marelon). However its not without it faults, stainless steel under certain circumstances is subject to a process called crevice corrosion. A stainless steel fitting installed below the waterl Iine duplicates these condition almost perfectly. Keeping the boat on a trailer is not a good preventative. You can google "crevice corrosion" for yourself, there is a ton of information about it. It can happen with stainless steel anywhere it has contact with with another metal or non-metal object and requires only miniscule amounts of moisture.

My only points in bringing this up time and again is simply because installing a SS scupper is not a once and done for all time repair, the scupper will still require regular replacement.

I would also be concerned if my boat sinks because of a scupper failure, due to an incorrect part for the application, installed by me, against all published standards, will my insurance still cover me? Its worth checking in to.

I'll stay with the factory Marelon one and expect to inspect and/or replace it as part of regular maintence, or I'll use the appropriate bronze fitting, if I can find one, which will still require regular inspection, but at least I should be able to see any corrosion if it is happening.

I'll take the huge hunk of metal over the plastic one every day. I'm nearly certain the problem with the plastic one is fatigue from flexing. The metal will last as long as I own my boat, and as it is hot here in NC and that moisture you reference is cooked off.

That said, interesting info and good to look for!

 

[mraz72]

well, I had a new plastic scupper installed last year. Here is my old scupper next to the SS version I was planning on installing.



Here is where it broke while installed on the boat. From the outside of the boat during an inspection you couldn't see the crack, not sure if you can from the other side.

 

[RobbieO]

well, I had a new plastic scupper installed last year. Here is my old scupper next to the SS version I was planning on installing.

View attachment 153066

Here is where it broke while installed on the boat. From the outside you couldn't see the crack.


View attachment 153067

So you decided against the SS scupper?

 

[RobbieO]

I'll take the huge hunk of metal over the plastic one every day. I'm nearly certain the problem with the plastic one is fatigue from flexing. The metal will last as long as I own my boat, and as it is hot here in NC and that moisture you reference is cooked off.

That said, interesting info and good to look for!

From what I have learned from researching, the corrosion seems to happen when there are gaps in the mating surfaces, or if there are gaps from the manufacturing process (i.e. weld). I you load the flange up with 5200 on the hull, and the threads and nut on the inside, you should be good. I may use 4200.

 

[mraz72]

So you decided against the SS scupper?

I'll probably install the SS scupper during opening next spring. Others here have it installed and no issues. If I have to replace it every 5 years (just to be safe) than so be it.

I agree with Julian, I like the hunk of metal vs the plastic scupper. The weight is quite noticeable its pretty stout.

 

[RobbieO]

I'll probably install the SS scupper during opening next spring. Others here have it installed and no issues. If I have to replace it every 5 years (just to be safe) than so be it.

I agree with Julian, I like the hunk of metal vs the plastic scupper. The weight is quite noticeable its pretty stout.

I'm going to purchase a plug that I can install from the outside if the flapper decides to break off. Something like this.

Shaw Plugs Expansion Plug, T-Handle, 1-1/2 In 52003 | Zoro

Order Shaw Plugs Expansion Plug, T-Handle, 1-1/2 In, 52003 at Zoro.com. Great prices & free shipping on orders over $50 when you sign in or sign up for an account.

www.zoro.com

 

[HangOutdoors]

If your boat is taking on water and you are in rough water, there may not be enough time or you may be unable to install that plug. I was proactive instead of reactive and just replaced mine with SS. It is definitely more solid than what I took out.

It is not expensive. Easy for anyone to do.

 

[Julian]

If your boat is taking on water and you are in rough water, there may not be enough time or you may be unable to install that plug. I was proactive instead of reactive and just replaced mine with SS. It is definitely more solid than what I took out.

It is not expensive. Easy for anyone to do.

And we've been replacing these plastic ones since probably 2008ish and I've never heard of a stainless one failing.

 

[RobbieO]

If your boat is taking on water and you are in rough water, there may not be enough time or you may be unable to install that plug. I was proactive instead of reactive and just replaced mine with SS. It is definitely more solid than what I took out.

It is not expensive. Easy for anyone to do.

I plan on installing the SS valve, but if the flapper ever broke off, I’d jump in and put the plug in from the outside. I boat in freshwster lakes only.

 

[Sbrown]

Once again, I wasn't trying to ruffle any feathers, just trying to help people make a well informed decision, regardless of what that decision is.

 

[sunbyrned]

Different opinions are healthy and keeps everyone informed of their options. That’s what’s great about this place.

 

[RobbieO]

Once again, I wasn't trying to ruffle any feathers, just trying to help people make a well informed decision, regardless of what that decision is.

Do you know when or if Yamaha uses Marelon?

 

[tdonoughue]

I think part of the takeaway should be this: There is no silver (or SS) bullet that will replace regular maintenance and inspection on any part of your vessel, including this scupper. I think the inspection interval is longer for the SS, probably, and the lifespan seems longer, at least anecdotally. But if you are not regularly opening your bilge and checking around (scupper, band clamps, splitting hoses...) you probably should, even if you have everything SS in there.

 

[RobbieO]

I think part of the takeaway should be this: There is no silver (or SS) bullet that will replace regular maintenance and inspection on any part of your vessel, including this scupper. I think the inspection interval is longer for the SS, probably, and the lifespan seems longer, at least anecdotally. But if you are not regularly opening your bilge and checking around (scupper, band clamps, splitting hoses...) you probably should, even if you have everything SS in there.

Amen to that

 

[zipper]

I plan on installing the SS valve, but if the flapper ever broke off, I’d jump in and put the plug in from the outside. I boat in freshwster lakes only.

If the rubber flapper breaks off the scupper, you do not need to plug up the scupper. The flapper prevents water from washing up on cockpit deck while you are in reverse. Especially in my 07 boat, there will be a static level of water in the scupper hose as the boat sits in the water, the flapper does not prevent all water from entering the scupper hose. My scupper thru hull is below the waterline. When the scupper hose cracks or the barbed 1 1/2" plastic thru hull snaps off, then you can jump in and plug it.

 

[Sbrown]

Do you know when or if Yamaha uses Marelon?

If they're following ABYC standards, the original one I would think is Marelon which is a plastic material.