Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 14-05-2019, 09:22   #1
Registered User

Join Date: May 2019
Posts: 36
Installing larger Seacocks, how to dril the larger hole

Had gate valves in my little sailboat. Wrestled with removing the thru hulls. Was going to just glass them over but I am just not confident enough to work with fiberglass under the waterline. Tried to get yards to do the work but after years it is just too difficult.



So I decided I could replace the gate valves with seacocks. Like everywhere size of drains could be bigger so went from 1" to 1 1/4". Hence I now need to drill a larger hole and realized that is not easy.


Do I have to fill the existing one inch holes with epoxy just to get soilid surface to guide the hole saw for the larger 1 1/4" hole? Could I glass the pad in and use that as the guide hole for the hole saw?



Extra points question: How critical is the thickness of the pad inside the hull for the seacock to sit on? I have seen 5/8" but not easy to find that around here. I don't feel like laminating up glass pads but I can only find 3/4" pre-made glass pads. It seems too thick though.


Extra Extrapoints: Anybody know if groco's premade pads with work with marelon valve bases? Groco dies not have measurements of the hole spacing between their holes.


Thanks much for any insights.
__________________

mike_kelly is offline   Reply With Quote
Old 14-05-2019, 09:33   #2
Do… or do not
 
s/v Jedi's Avatar

Cruisers Forum Supporter

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 9,478
Re: Installing larger Seacocks, how to dril the larger hole

Take a small scrap piece of plywood and drill it with the correct size holesaw. Now hold that piece over the spot you want to drill through the hull and use it to keep the holesaw steady until it has cut a bit into the fiberglass after which you don't need the guide anymore

Did you check the Compass Marine website on how to install this? Backing plate, 5200 etc...
__________________

s/v Jedi is offline   Reply With Quote
Old 14-05-2019, 10:25   #3
Marine Service Provider

Join Date: Sep 2016
Location: usa
Posts: 54
Re: Installing larger Seacocks, how to dril the larger hole

Beat a wood bung in the current hole. Drill new hole as normal.
svninkasi is offline   Reply With Quote
Old 14-05-2019, 10:45   #4
Registered User

Join Date: Dec 2015
Location: Fort Pierce Fl
Boat: Gulfstar 36 MS
Posts: 184
Re: Installing larger Seacocks, how to dril the larger hole

Two hole saws, one the size of current hole and one the size of the hole you want. Put the large one on the arbor first then the smaller leaving it proud of the larger one by a quarter inch. Line up the holes that the two pins go through and tighten the lock nut. Place small hole saw in current hole and start slowly.
Outlaw7 is offline   Reply With Quote
Old 14-05-2019, 13:50   #5
Registered User

Join Date: May 2019
Posts: 36
Re: Installing larger Seacocks, how to dril the larger hole

All ideas much better than having to epoxy the hole over. Very nice thanks.

I am following forespars instructions, because I like Marelon seacocks, so it is a little different than most bronze techniques. I don't like the idea of putting in 4 holes instead of one.

I like the double hole saw if my arbor is long enough to accept two blades.


How about the extra credit questions?


1/2" or 3/4' pads, glass, wood or groco whatever they use.
mike_kelly is offline   Reply With Quote
Old 14-05-2019, 13:59   #6
Senior Cruiser
 
bstreep's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: San Antonio, TX/Port Aransas, TX
Boat: 1990 Macintosh 47, "Merlin"
Posts: 2,337
Re: Installing larger Seacocks, how to dril the larger hole

What Outlaw just said. It absolutely works, just did a 5" hole in our deck for the new windlass. I was in your shoes, and our rigger gave me that idea. Worked flawlessly.
__________________
Bill Streep
San Antonio/Port Aransas, TX
bstreep is offline   Reply With Quote
Old 14-05-2019, 14:02   #7
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 21,209
Re: Installing larger Seacocks, how to dril the larger hole

The wood bung works to holesaw a larger hole. The pad at 3/4 should, in most cases, be fine. Often thru hull mushrooms are too long.
But hey, measure your mushroom, measure the hull thickness at the hole!
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 14-05-2019, 14:22   #8
Registered User

Join Date: May 2019
Posts: 36
Re: Installing larger Seacocks, how to dril the larger hole

Sounds good. Time to get this little beast finished.
mike_kelly is offline   Reply With Quote
Old 15-05-2019, 08:23   #9
Registered User

Join Date: Nov 2010
Location: BC
Boat: O'Day 40
Posts: 452
Re: Installing larger Seacocks, how to dril the larger hole

Before you buy Marelon, look at Trudesign.

Unlike the marelon they never stick open or closed.

If you've ever had to deal with a stuck marelon valve with a full holding tank and no available pump out you'll understand how important this is.
__________________
Trying to make new mistakes.
bcboomer is offline   Reply With Quote
Old 15-05-2019, 08:25   #10
Registered User

Join Date: Jul 2017
Location: Vancouver
Boat: CS 27
Posts: 7
Re: Installing larger Seacocks, how to dril the larger hole

I agree with Outlaw. I am a professional carpenter (30 years+) and the two hole saw techniques is simple and works well. Start the drill slow so the smaller guide hole saw doesn't jump out of the hole and gradually bring the larger holesaw to the surface until you start cutting into the fibreglass. Once the larger saw is cutting then the rest is easy.
jooa is offline   Reply With Quote
Old 15-05-2019, 08:27   #11
Registered User

Join Date: May 2019
Posts: 36
Re: Installing larger Seacocks, how to dril the larger hole

I had Marelon Seacocks on my last boat for 10 years. So I appreciate that the Trudesign are nice looking products but the Marelon Seacocks were the least of my worries on my last boat. They just need to be exercised occasionally.
mike_kelly is offline   Reply With Quote
Old 15-05-2019, 08:29   #12
Registered User
 
akprb's Avatar

Join Date: Jan 2015
Location: Alaska
Boat: Boatless
Posts: 880
Re: Installing larger Seacocks, how to dril the larger hole

Quote:
Originally Posted by Outlaw7 View Post
Two hole saws, one the size of current hole and one the size of the hole you want. Put the large one on the arbor first then the smaller leaving it proud of the larger one by a quarter inch. Line up the holes that the two pins go through and tighten the lock nut. Place small hole saw in current hole and start slowly.
Clever!
__________________
www.sailingohana.com

"Take it all in, it's as big as it seems, count all your blessings, remember your dreams" JB
akprb is offline   Reply With Quote
Old 15-05-2019, 08:41   #13
Senior Cruiser
 
Lancerbye's Avatar

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Ladysmith,BC, Vancouver Island , Canada
Boat: Lancer 44 Motorsailer
Posts: 1,791
Images: 32
Re: Installing larger Seacocks, how to dril the larger hole

Going from 1 to 11/4 in. is not a big jump. You could also just mark it and use a Dremel tool to enlarge to hole. I have found that often times the hole required doesn't have a matching hole saw size, either too big or too small which is why I usually end up making it a little smaller and resize to exact fit with a Dremel.
__________________
The basis of accomplishment is in never quitting
Mengzi Meng-tse
Lancerbye is offline   Reply With Quote
Old 15-05-2019, 09:16   #14
Registered User

Join Date: May 2019
Posts: 36
Re: Installing larger Seacocks, how to dril the larger hole

Quote:
Originally Posted by Lancerbye View Post
Going from 1 to 11/4 in. is not a big jump. You could also just mark it and use a Dremel tool to enlarge to hole. I have found that often times the hole required doesn't have a matching hole saw size, either too big or too small which is why I usually end up making it a little smaller and resize to exact fit with a Dremel.

I guess I expected the requirement to have a pretty price fit would make a dremel a rough solution, at least for my dremel skills but hopefully 1 1/4" should be a pretty standard fit.


It was a major job getting the old thru hulls out. Given it was built with a bullet proof hull in the days when they used as much glass as the thickness of typical wood builds. I worked on it for along time then just finally drilled it out with a step tapered drill bit. Ugly but I got them out. One of the previous owners had filled one of the three thru hulls. I am not sure why. There are three together. Two cockpit drains that are supposed to be opposite sides and crossed hoses and the middle one for the sink drain. They had removed one of the cockpit drains and T-ed the sink into one of the cockpit drains. Which means one of the cockpit drains was likely to back fill the cockpit under significant heeling.


So I am going to put them back the way they were designed, especially since I don't know what he/she did to fill in the one removed. It is recessed under the water side like they glued in a bung that did not reach the exact outside of the hull. They did the same when removing the toilet output and I worry about the quality of the "repair".
mike_kelly is offline   Reply With Quote
Old 15-05-2019, 09:24   #15
Registered User

Join Date: Sep 2016
Location: Japan
Boat: '82 Mikawa MKII 30'
Posts: 94
Re: Installing larger Seacocks, how to dril the larger hole

Those ideas for cutting a larger hole are GREAT! But when going from 1" to 1 1\4", you're talking about so little material that the saw blades may not be able to cut a smooth line. When I removed my brass(no, not bronze, brass!) gate valves, I had to go from 1" to 1-1/4" I carefully scribed the line with marker, chucked a reamer bit in the drill and slowly and carefully went at it! It took very little time and I was able to make the hole just the right size. I have used Marelon seacocks for over 20 years and they all work great!
The thickness of the pads is dictated by the amount of curvature in the hull and size of rough spots that need to be covered. On mine, I used 1/2" marine plywood for pads: cut them with a circle cutter on the bandsaw, with a nice bevel, drilled my holes to fit the thru hull, did some fairing when there was a rough glass spot inside the hull or a curvature, to make them go flat against the hull, then installed the thruhull and snugged the thru hull in tight with the nut, using copious amounts of polysulfide compound to make a tight seal.
Then I used another 1/2" disc to go over the thruhull stem and nut, only reaming out enough material around the hole to make the pad sit flush on the first one, covering the thruhull nut. Then I threaded on the Marelon seacock and tightened it down on the second pad, screwed in the barbed hose nopple in and connected the hose.
Since the pads are wood, I made sure the base of the seacocks would always be dry. Marine plywood will withstand a certain amount of wetness, as long as it isn't prolonged.
__________________

Matsubob is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Replacement Seacocks? 42AFJ Plumbing Systems and Fixtures 31 26-03-2010 11:33
Replacing through hulls and seacocks Fotoman Construction, Maintenance & Refit 2 20-04-2009 18:54
Seacocks - Perko, Groco, Forespar, Apollo SkiprJohn Plumbing Systems and Fixtures 24 22-02-2009 12:08
removing seacocks and below water screens defever Construction, Maintenance & Refit 2 07-11-2008 11:56
Seacocks, bronze or maleron? Steve Rust Construction, Maintenance & Refit 8 06-03-2006 21:32



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 08:46.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.