Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 18-03-2013, 18:59   #1
Registered User
 
timbenner's Avatar

Join Date: Jan 2007
Location: Ponte Vedra Beach, FL
Boat: Lagoon 380, 38', I Dream of Jeanne
Posts: 313
Images: 7
When to replace thru hulls??

I have a 2002, 380, on the hard, finishing up a refit. How do I know if I should replace the thru hulls?? Any testing advise?? Are the thru hulls like rigging and should be replaced every "X" years??

Tim
__________________

__________________
timbenner is offline   Reply With Quote
Old 18-03-2013, 19:25   #2
Senior Cruiser
 
osirissail's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: A real life Zombie from FL
Boat: Gulfstar 53 - Osiris
Posts: 5,416
Images: 2
Re: When to replace thru hulls??

Well, first things first - the "Through hull" is the screw-in fittings that passes through the hull and into the "seacock." Which is the valve that allows you to keep the ocean on the outside of the hull.

Then there is the matter of whether your "Seacock/Through-hull" combination are made of metal (e.g. bronze) or resin (e.g., Marelon - or God forbid PVC).

Typically, bronze or actually any Seacock material gets "sticky" and unless lubricated and exercised become very difficult to open and close. So a schedule of lubrication and exercise (opening and closing) them is important. If they have never or rarely ever been lubricated or exercised then they might become "frozen" and you cannot open/close them without risking breaking them. In that case, replacing them would be advisable. Or at least removing or disassembling them to clean and refurbish makes sense.

Otherwise, if they are functional and not broken, cracked or otherwise compromised there would be no reason to replace them. However, if the Seacock/Through-hull is bronze it is possible that it has been subject to stray electrical currents and "de-zincified" which turns the normal bronze colored metal "pink." Then it would also be advisable to change them and correct the stray electrical problems.

Just like screws, Through-hulls come in different head styles - mushroom/round head or flush/flat head. Sometimes if the boat has been run down some hard dock or other obstructions the mushroom/round head style Through-hull can get the portion that is on the outside surface of the hull, scrapped off or broken. Then again it would be advisable to install new ones.

Also if the Seacock is not a tabbed base "flanged" style which is bolted to the hull and instead is merely being held in place by the threads of the Through-hull, it would be advisable to remove the Through-hull and check it for cracks in the threaded section. However, since the Through-hull portion is normally "bedded" with adhesive caulk is it rarely possible to remove it without breaking or destroying the fitting. So if there is no indication of any leakage leaving the system alone also makes sense.

So there are several variables to consider as to whether "replacing" them is advisable or not. More important sometimes is to check the hoses attached to the Seacock and the hose clamps and their condition as the hose clamps rust and break or the hoses dry out and get rigid and fracture or crack.
__________________

__________________
osirissail is offline   Reply With Quote
Old 19-03-2013, 10:59   #3
Registered User
 
timbenner's Avatar

Join Date: Jan 2007
Location: Ponte Vedra Beach, FL
Boat: Lagoon 380, 38', I Dream of Jeanne
Posts: 313
Images: 7
Re: When to replace thru hulls??

Osiris,

Thanks for the input. I think I've got factory bronze thru hulls on a Lagoon 380. I'm thinking Titanium, so I never have to worry about them again. Hose Clamps from Titan are 100 Percent Titanium
__________________
timbenner is offline   Reply With Quote
Old 19-03-2013, 11:10   #4
Don't ask if you can't handle it
 
sailorboy1's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: On the boat somewhere
Boat: Hunter 410
Posts: 12,312
Re: When to replace thru hulls??

Quote:
Originally Posted by timbenner View Post
Osiris,

Thanks for the input. I think I've got factory bronze thru hulls on a Lagoon 380. I'm thinking Titanium, so I never have to worry about them again. Hose Clamps from Titan are 100 Percent Titanium
If you think that the "normal" 316SS clamps are not enough then I think you have a bigger issue! The titanium clamps probably aren't as strong, but it doesn't really matter.


As mentioned I would be more concerned about the thru fittings than the valves. On my last boat I went to replace a frozen 3/4" valve, only to find out the 2-1/4" thru fitting on the valve next to it had completely corroded away and the largest hole in the boat was being held together by caulking (a stray current issue)!

This is thread drift, but that experience also let to my being in the don't bond sea fittings to the boats electrical circuits. I my opinion connecting things that aren't suppose to have current going though them to something that does is asking for a problem.
__________________
jobless, houseless, clueless, living on a boat and cruising around somewhere
sailorboy1 is online now   Reply With Quote
Old 19-03-2013, 11:17   #5
Registered User
 
timbenner's Avatar

Join Date: Jan 2007
Location: Ponte Vedra Beach, FL
Boat: Lagoon 380, 38', I Dream of Jeanne
Posts: 313
Images: 7
Re: When to replace thru hulls??

They claim that Titanium is 40% stronger and 40% lighter than Stainless Steel. I gave you the wrong link to titanium thru hulls. Here's the correct one: Thru-Hulls - Titanium
__________________
timbenner is offline   Reply With Quote
Old 19-03-2013, 11:18   #6
Registered User
 
timbenner's Avatar

Join Date: Jan 2007
Location: Ponte Vedra Beach, FL
Boat: Lagoon 380, 38', I Dream of Jeanne
Posts: 313
Images: 7
Re: When to replace thru hulls??

Titanium looks like the best long term solution. The cost of titanium is competitive as well.
__________________
timbenner is offline   Reply With Quote
Old 19-03-2013, 11:28   #7
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,363
Re: When to replace thru hulls??

If you dont mind being a Beta test go for it. I tend to stick with proven products for safety items. Not that I dont respect Titanium's corrosion resistance, but it can be pretty crack prone if not properly engineered. I dont think a 2002 boat should need it's bronze seacocks replaced though, unless they are showing defects.
Bronze 3/4"= $14
Titanium = $60
You probably have bronze thru hulls with ball valves screwed onto the stems? I wonder what the combo of Bronze and Ti does to the bronze...?
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 19-03-2013, 11:43   #8
Marine Service Provider
 
boatpoker's Avatar

Join Date: Nov 2008
Location: Toronto, Ontario or Bahamas
Boat: Benford 38 Fantail Cruiser
Posts: 2,593
Re: When to replace thru hulls??

Every Lagoon I have seen has chrome plated NPT brass ball valves on NPS bronze throughulls (In no way can this arrangement be called a "seacock"). A UK Marine Surveyor has several articles on this issue which some consider very serious particularly in salt water. Compass Marine also has some terrific articles on this issue and both sites have some great photos of potential problems.
__________________
That hysterical laughter you hear as you sail a way in your "new" boat ..... is the seller.
boatpoker is offline   Reply With Quote
Old 19-03-2013, 12:17   #9
Registered User
 
sailvayu's Avatar

Join Date: Mar 2006
Location: Fort Myers FL
Boat: Irwin 40
Posts: 878
Re: When to replace thru hulls??

I agree with boatpoker the French boats use a poor quality brass. It is CE approved but I would not have it on my boat. Also laggons use ball valves on thru hulls not a proper seacock with flange. I would replace them all with proper seacock like those made by Apollo, Combraco, Buck Algonquin, or Groco. I have had lagoon fittings crumble in my hand while working on them they were so corroded.
__________________
Capt. Wayne Canning, AMS
www.projectboat.info
http://sailvayu.com/
sailvayu is offline   Reply With Quote
Old 19-03-2013, 14:51   #10
Registered User
 
careka's Avatar

Join Date: Apr 2009
Location: Egersund,Norway
Boat: Lagoon380 Comfort#637
Posts: 704
Images: 2
Send a message via Skype™ to careka
Re: When to replace thru hulls??

Lubricate ?? with what, ?? oil, ?? or. Seacocks. ball valves,
__________________
careka is offline   Reply With Quote
Old 19-03-2013, 15:53   #11
Senior Cruiser
 
osirissail's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: A real life Zombie from FL
Boat: Gulfstar 53 - Osiris
Posts: 5,416
Images: 2
Re: When to replace thru hulls??

I wouldn't get all that excited about "titanium" hose clamps or though-hulls fittings. First off, the Titan hose clamps are "perforated" bands. That is a mark of an inferior hose clamp. The 316SS AWAB clamps are, IMHO, the best since they are made 316SS parts and used indented threading. See photo below. AWAB Hose Clamps

The problem with perforated hose clamps is that rust or stress fractures develop in the very narrow edge of the clamp strap. Then they break regardless of the metal used to make hose clamp band.

As to using titanium through-hull fittings - more than likely you will be using bronze seacocks or whatever and whenever you have two dissimilar metals connected together in the presence of salt water - here comes electrolysis and rapid deterioration of the less noble metal.

If indeed the Lagoon used ball valves mounted on the stems of through-hull fittings, I would agree with removing them and replacing with flanged base seacocks and matching through-hull fittings. Using flanged base seacocks that are bolted to the hull removes all the stress on the through-hull fitting along with eliminating the problem of breakage if somebody or something heavy falls on the seacock/valve.

And I would agree with the others that standard quality brand name seacocks and through-hull fittings are perfectly fine and there are probably better areas to spend "extra" money than going with exotic metal fittings.
Attached Images
 
__________________
osirissail is offline   Reply With Quote
Old 19-03-2013, 15:56   #12
Registered User

Join Date: Feb 2011
Location: South Florida
Boat: Gibson 50'
Posts: 295
Re: When to replace thru hulls??

Quote:
Originally Posted by careka View Post
Lubricate ?? with what, ?? oil, ?? or. Seacocks. ball valves,
I believe that common practice on any boat is to lubricate anything that needs maintenance with large quantities of whatever cash is on hand.
__________________
offline is offline   Reply With Quote
Old 19-03-2013, 17:11   #13
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,363
Re: When to replace thru hulls??

Quote:
Originally Posted by sailvayu View Post
I agree with boatpoker the French boats use a poor quality brass. It is CE approved but I would not have it on my boat. Also laggons use ball valves on thru hulls not a proper seacock with flange. I would replace them all with proper seacock like those made by Apollo, Combraco, Buck Algonquin, or Groco. I have had lagoon fittings crumble in my hand while working on them they were so corroded.
This is good advice, concentrate on replacing with a proper flanged seacock as a higher priority rather than exotic alloys.

"I wouldn't get all that excited about "titanium" hose clamps or though-hulls fittings. First off, the Titan hose clamps are "perforated" bands. That is a mark of an inferior hose clamp. The 316SS AWAB clamps are, IMHO, the best since they are made 316SS parts and used indented threading. See photo below. "
If the Titanium clamps are perforated, then I agree... I know Ti sheet metal very well..... I worked with it for many years. It is very crack prone compared with stainless. Unperforated might be good though.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 19-03-2013, 17:33   #14
CF Adviser
 
Bash's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: sausalito
Boat: 14 meter sloop
Posts: 7,260
Re: When to replace thru hulls??

Quote:
Originally Posted by careka View Post
Lubricate ?? with what, ?? oil, ?? or. Seacocks. ball valves,
I use white lithium grease for seacocks. You can get it in spray canisters, and apply during haul outs.
__________________
cruising is entirely about showing up--in boat shoes.
Bash is offline   Reply With Quote
Old 19-03-2013, 17:36   #15
Registered User

Join Date: Sep 2009
Location: Mackay,QLD, Australia
Boat: planning a approx 45ft cat
Posts: 3,651
Images: 3
Re: When to replace thru hulls??

Thru hulls and ball valves, not sea cocks on a Lagoon 400.

I would be looking at the link below at Compass Marine and consider installing flanged seacocks.

Replacing Thru-Hulls and Seacocks Photo Gallery by Compass Marine at pbase.com
Attached Thumbnails
Click image for larger version

Name:	DSC_0163.jpg
Views:	686
Size:	405.2 KB
ID:	57365  
__________________

__________________
downunder is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 05:52.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.