I know this question has been discussed at length but I couldn't really find anu common consensus...
I found a couple of leaky under water thru hulls and decided to replace all. They are flush, except for the galley raw water intake, all marelon, and include a conglomeration of sea cocks and ball valves, some marelon, some bronze or brass... Not sure how to tell... But all standing very high of the hull.
I went to catalina direct and saw the one piece marelon valve and thru hull and liked what I saw, then read some scary stuff here.
What's the current common wisdom?
My boat had ball valves on all thru hulls. I changed all thru hulls to Marelon flanged seacocks with backing plates. I chose Marelon instead of bronze because no grounding required, good test results, and an old friend of mine told me that sometimes bronze is overtightened and can damage the fiberglass.
By scary stuff on this website do you mean the guy who took the handle off and water flooded into his boat?
Our MKII from 2002 has all Marlon thru-hull valves (http://www.forespar.com/OEM-Valves.shtml (http://www.forespar.com/OEM-Valves.shtml)). Don't know their life expectancy, but these all appear to be original. So at least 15 years so far. We haven't had an issue with any of them other than sometimes they have stuck. Never a leak. I hear that I should be using a specific lubricant on them before I launch the boat to ensure a smooth motion. If anything I have found that its been more difficult for me to know sometimes which way to turn the lever when i want to close it? I must be mildly dyslexic when trying to close them. :(
Mine appear to be original as well, that makes them 23 ....
QuoteI must be mildly dyslexic when trying to close them. :(
You are not alone in my short experience with forespar I had same issue - On the other hand trudesign handle is not symmetric and easy to identify turn direction
I have already made a decision on replacing seacocks , still unsure about thruhulls. Can't find any information on how these age to push me over the edge.
Some say "When in doubt , rip it out" :?
Are yours leaking? Other than being 23 years old, is there an issue with them? The saying that I like is: "If its not broken, leave it alone."
If you are concerned about an unexpected break, you should always have a plug or two on board, that fit your thru-hulls. i keep a "TruPlug" in our cockpit lock at all times, and hope to never use it.
- no leaks
- no clear issues other then age / unknown deterioration of the material
Quote"If its not broken, leave it alone."
point taken
I have always kept a set of wood plugs on my boats - your "TruPlug" suggestion looks superior. I'm definitely getting these on board.
Jon W. - Yep... the handling falling off or breaking off, although it sounds like they can break off without flooding the boat?
MarcZ - I'd suggest we pool our data if I had any to offer. I have to do something, though, 'cause I removed all mine last weekend. :O
Fred - I'm leaning toward going back with the marelon ones from Catalina Direct on the assumption that they can't be sinking boats left and right or surely they wouldn't still be selling them, right?!
For what it's worth, of the 5 size/configuration combos they carry, they have 1 or 2 of three of them in stock but they are typically special order and take 1-2 weeks.
I have all mine in my car, so I'll take inventory tonight and see where I stand.
Marc, I love the look of that Truedesign but I think you are right... that wouldn't work with our flush mount. Filling and redrilling doesn't sound like any fun.
I'm planning to use trudesign seacock with existing or new forespar thruhull to avoid any modification of the hull
I already have one dry fitted and it looked and felt solid.
Will report more once it stops snowing and temp gets north of 32 :wait
If you've got any pictures of those together, I'd love to see it. Sounds like a promising combo.
My apologies if this is obvious to everyone, but before dismissing Marelon it might be worth clarifying definitions -
"Sea cock is the term for a type of valve used to control intake or discharge of water through the hull. It is operated by a lever type handle usually operating through a 90° arc, giving a clear indication of whether it is open or shut, and is typically of the two following types:
Flanged Sea Valve – A Seacock with an integral flange used to individually and securely mount the device directly to the boat hull structure.
In Line Ball Valve – A Seacock designed to be supported entirely by the through-hull fitting"
I had all "In Line Ball Valve" types (see example 1st photo) when I bought the boat. I'd guess most of you do as well. I changed to all "Flanged Sea Valve" types with backing plates (see example 2nd photo) shortly after buying the boat. Lower profile and much more robust since the valve attaches at the hull. I would not use an "In Line Ball Valve" type regardless of composite or bronze if I can avoid it.
Marelon has both types available. I believe Catalina Direct only sells the "In Line Ball Valve" type.
Paralysis by analysis... maybe I'll just sit this season out and sail next year!
Another thing to consider is the type of tailpiece that connects to the valves and seacock and that it is the "correct" material, Marrlon-type material, not nylon, brass or PVC and that it has enough length to be DOUBLE CLAMPED, as is required for hoses under the waterline.
I am going through this exercise myself right now, as my boat has some PVC Tee fittings and some single clamped hose barbs. Trying to "clean-up" that stituation is a PIA as well as the knees. All very tight under the cabinetry in head and galley sink. I currently have OEM Marelon thru-hulls and vavles that work fine but plan to go the route Jon went with flanged seacocks, replacing my existing old flush mount Marelon thru-hulls (same as I have now) but replace the seacocks with flange mounted ones with backing plates. I like the added strength of the flange. Will do at next hullout in Oct.
John W - CD does sells both types
When you were installing backing plates was your hull relatively flat or did you have to deal with a bump like I have ?
Jon, not sure what you mean about a "bump"? Looks to me like the hull was countersunk to accept flush mounted thru-hull for less drag. Standard. Our are you talking about a "bump" on the inside of the hull for added thickness to act as a faux backing plate for a non-flange mounted screw on thru-hull nut--which would result in a bit a complication when switching to a flange mount one with the backing plate flush to the hull?
I'm referring to the inside bump getting in the way of easily adding a mounting plate.
Almost all thruhulls (or actually surrounding areas) in my boat look like this and it appears to be sock factory no PO mod traces of any kind.
I'm partial to "trudesign" collar that would simply go around the bump providing good lateral support and no need for very custom backing plates
Unless someone can suggest better method.
Just looked and you're right Catalina Direct does have both. Looks different than mine, must be a new model.
I had them changed out by professionals, but my inside hull surface was flat.
Noah,
Following up.
Just to be precise so there's no misunderstanding hose barbs, Etc., should be double clamped if the line terminates under the waterline. In other words a bilge pump hose to a through hull above the waterline wouldn't be subject to flooding. Conversely, a connection that is self above the waterline, but on a hose that terminates below the waterline, should be double clamped because it could be subject to siphoning even though the given connection is above the waterline (if that exclamation makes any sense.)
Not only are tailpieces at issue, but likewise any hose barb adapters and/or pipe nipples ( such as on a strainer.)
Looking through your photos again just now, telltale evidence tells me you have no marelon down there ( except the valves). Possibly the only *safe* fitting is the one I sent for the sink drain. Caution to all - it was S.O.P. for CTY to use PVC fittings.
kk
Yep, hence my desire to change-out all! I just threw in that double clamp "reminder/fact" as it looked like Jon's were not double clamped--nor are some of mine. I bet there are others out there in this position as well. Just putting all the parts together, and the time, and squeezing into the the nooks and crannies, has been a challenge.
Mine under the sink are not double clamped but are on the list when I relocate the raw water strainer. Not sure how to fit two clamps on the hose barbs. The fittings in the photo are reinforced nylon, not pvc.
Jon
I am unsure what you mean by "reinforced" nylon?
They look like plain nylon fittings from the pics, but a little hard to tell.
If you email me and inventory of what you need as far as thread/hose size, I can send you barbed adapters that are "Marelon equivalent" as far as strength and are long enough to double clamp.
kk
They were labeled glass fiber reinforced nylon.
Quote from: Jon W on March 13, 2017, 09:04:55 PM
They were labeled glass fiber reinforced nylon.
Which is what Marelon is... :thumb:
As for the PVC T's and such, I'm getting rid of mine at the same time. The valves I'm most considering now are the Forespar OEM Series 93's. They may be the same that CD sells, but I can't be sure since they'll only tentatively confirm that they are forespar at all. I know the series 93's are much newer and stronger than the previous generation which came after my boat was built.
Anyway, they come in a wide variety of configurations... I'm hoping enough that I can have nothing but the valve and parts it came with plus the hose.
I was pretty impressed with MaineSail's destruction test of the thing!
http://www.forespar.com/OEM-Valves.shtml (http://www.forespar.com/OEM-Valves.shtml)
Do those valves fit on the old style Forespar thru hulls? Or must you install and entire assembly?
kk
I'm not sure if it is officially supported configuration but answer is: Yes.
You can leave the Forespar thruhull only swap the nut from forespar to trudesign (allowing load bearing collar to fit nicely) - Most likely exact setup I'm going to use.
Will post some pics once I get to the boat.
My boat doesn't have the internal bumps but I can't seem to post pictures... I've tried including them as attachments and see them uploading... but the post never shows up. Can someone educate me?
Mike,
Posting and RESIZING Photos 101 http://c34.org/bbs/index.php/topic,3701.0.html (http://c34.org/bbs/index.php/topic,3701.0.html)
Quote from: rmbrown on March 15, 2017, 08:32:41 AM
My boat doesn't have the internal bumps but I can't seem to post pictures... I've tried including them as attachments and see them uploading... but the post never shows up. Can someone educate me?
Mike
Does the text of your post show up?, and just not the pic attachments?
What size are they? If any are over 200 kb (or 450 kb total), you should see an error message that they were too large to post. No error message shows?
kk
Here's my lack of bump photos...
Wow Mike - pics show that's just wrong on so many levels. Good for you for eliminating all the faux pas.
Looking at the series 93 they look very cool - love the idea of the integral hose barbs.
With the 1/2"-3/4" size, they barely give you enough room to double clamp (1.3" and 1.4" long barbs) You really have to make sure you slam the hose and clamps against the body. You'd think Forespar could have been a little more generous on that - What's the cost of another 3/8" of "plastic"??
ken
No "bump" - nice, and there are only 6 boats between us...
:shock: Someone was definitely "creative" with these valves.
I like the green one. :wink:
Got two... Give me your mailing address. ;)
Well this isn't going as smoothly as I'd hoped... Surprise!
I have three 1/2 valves and three 3/4 inch valves. Catalina no longer has or uses the 1/2 in valves, so I contacted Forespar. I'm working with Randy there trying to identify what I need but the outer end of the 93 series thru-hulls doesn't have the same cross section as what came off the boat. What came off the boat were all the same OD, independent of ID/thread size. Other than filling in the flush countersinks and going to mushrooms or redrilling for new flush thru hulls, anyone got any ideas?
Mike
Do the series 93 sea cocks fit your 3/4 thru hulls, or neither one?
Caution on on the term "valves." Forespar has 93 "valves" which are npt tapered thread, and 93 "sea cocks" which are all nps straight thread.
What are the actual "outer part" dimensions ?
the OD of the outside flange is 2.3-2.4 inches... pictures of my thru hulls are here that show more dimensions if that's not what you were asking.
https://www.dropbox.com/sh/ogbrll19ydf3q64/AAB2NG9p71yFDgryTxcNCB8Ja?dl=0 (https://www.dropbox.com/sh/ogbrll19ydf3q64/AAB2NG9p71yFDgryTxcNCB8Ja?dl=0)
Mike: regarding your comment from your strainer thread:" I intended to replace my thru hull along with the valve but the shape and size of the flush "mushroom" isn't the same. Forespar tells me that they can make the valves with a thread on the bottom to match the old thru hulls. They aren't flanged in the traditional sense... no thru bolts... but they have a wide base to support them from failing due to rocking to one side and, according to Maine Sail's video test, they are plenty strong in shear."
1. Are you saying Forespar is custom-making valves threaded to match your existing thru-hulls? Or are they off the shelf. 2. what are the OD sizes of each and their purpose/location in your boat? Unfortunate that you have to put new valves on old thru hulls.
I am weighing the same project at my next haulout in Oct./Nov. Have you discussed with Jon W., he recently changed all his to flanged seacocks and new thru hulls, and may have some input to assist you?
My understanding is that they can make their valves with a lower portion to match the old thru hulls or the new ones, by putting an "N" at the end of the part number, but I'm not 100% yet.
What I got from my contact there is that if I send him the dimensions of my thru hulls and the dimensions of my existing hose barbs, he can sell me a valve that will use my old thru hull and end in the same size barb, pointed accordingly. That way, I avoid having to fill and redrill for the thru-hulls. Not 100% committed but that's where I'm headed today.
Mike,
That sounds like good news.
Is it simply that your thru hulls (some of them) are too small (ie, 1/2") diameter? But are the "correct" straight, non-tapered thread form?
Or are your thru hulls completely different from the "standard" thru hulls for the series 93 seacocks?
ken
the diameters of the flush "plug" portion are significantly larger on the old ones than the new ones. Of course, I can fill and redrill, but I'd prefer not to if I convince myself that it's a safe option.
Sorry, I'm not being clear.
I'm not asking about the new thru hulls and how they fit your hull holes/recess do to speak. .
What I'm saying is the old thru hull threads do not fit the "standard" series 93 seacocks, correct?
Are the two thread forms (your old vs new 93) completely different?
Or is it just that your 1/2" thru hulls do not fit the new Seacocks (e.g. they are an odd diameter.)
I think it's an NPS vs BSP issue. Different number of threads per inch, for many diameters, and a different shaped thread... One rounded, one flat. All that said, it would probable work mechanically, just may be hard to seal.
New valves have arrived... :)