Rebedding Water Tank Lid - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 13 Old 1 Week Ago Thread Starter
Junior Member
 
Join Date: May 2016
Location: Key West, FL
Posts: 12
Thanks: 9
Thanked 1 Time in 1 Post
Rep Power: 0
 
Rebedding Water Tank Lid

Hi Sailnet -

I have a forward water tank on our '96 Crealock 34 that has numerous leaks around the perimeter. It is currently bedded with silicone (only 3 years ago), which after researching, seems like an ineffective bedding compound considering the extensive upward pressure of 40 gallons of water when in a seaway.

Can anyone walk me through the process of removing the lid (it has an inspection port)?

And why silicone is typically used? If you can recommend a different bedding compound, that would be great. What are the pros and cons?

See photo for reference. Many thanks, Celia
Attached Thumbnails
fwd water tank.jpg  
toddoh72 is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 13 Old 1 Week Ago
Senior Member
 
midwesterner's Avatar
 
Join Date: Dec 2015
Posts: 498
Thanks: 6
Thanked 17 Times in 17 Posts
Rep Power: 2
 
Are you actually contemplating re-bedding the cover, removing all of the screws? It's hard to tell from your photo what type of screws those are, philips head?

As close as all of the screws are together, I wouldn't think there would be that much pressure from just sloshing water. You would probably want to use some type of sealant that wouldn't taint the water or impart some taste to it. Do you know what was under there originally? Was it some type of sealant or a gasket?

I would think that you would want something that becomes inert once it is cured. This is one of the few places on a boat where kitchen&bath grade silicon might be appropriate. You are not rebedding a deck fitting.

You might also be able to find a large sheet of plastic closed cell foam you could use to cut a gasket using the lid as a template.

I'm just brainstorming.
midwesterner is online now  
Quote Quick Reply Share with Facebook
post #3 of 13 Old 1 Week Ago
Senior Member
 
Join Date: Apr 2008
Posts: 716
Thanks: 30
Thanked 35 Times in 35 Posts
Rep Power: 10
 
Re: Rebedding Water Tank Lid

Use PTFE gasket on a roll, which provides soft, highly compressible gasketing. You'll find it at McMaster-Carr or plumbing suppliers who deal in flange to flange piping. Select tape approx 1/3 the width of the flange. When compressed the two sealing surfaces are torqued down it provides a very wide, thin ribbon-like joint sealant and it fills the irregularities on rough or uneven surfaced flanges. PTFE gasketing does not support bacterial growth and is FDA compliant for water and food service.
Hudsonian is online now  
Quote Quick Reply Share with Facebook
 
post #4 of 13 Old 1 Week Ago
al brazzi
 
Join Date: Oct 2014
Location: Lower Chesapeake bay
Posts: 1,579
Thanks: 0
Thanked 55 Times in 55 Posts
Rep Power: 3
 
Re: Rebedding Water Tank Lid

Quote:
Originally Posted by Hudsonian View Post
Use PTFE gasket on a roll, which provides soft, highly compressible gasketing. You'll find it at McMaster-Carr or plumbing suppliers who deal in flange to flange piping. Select tape approx 1/3 the width of the flange. When compressed the two sealing surfaces are torqued down it provides a very wide, thin ribbon-like joint sealant and it fills the irregularities on rough or uneven surfaced flanges. PTFE gasketing does not support bacterial growth and is FDA compliant for water and food service.
Sounds like the Butyl I use on deck, no question this is the right stuff, I might suggest tightening a little let it settle and snug a bit more, these types of sealants take a while to re-form when tightening no need to squeeze it all out. You should see it even out as you go.
albrazzi is online now  
Quote Quick Reply Share with Facebook
post #5 of 13 Old 1 Week Ago
Daniel - Norsea 27
 
Rhapsody-NS27's Avatar
 
Join Date: Apr 2012
Location: Me: VA Boat: Deale, MD
Posts: 1,113
Thanks: 111
Thanked 53 Times in 47 Posts
Rep Power: 6
 
Re: Rebedding Water Tank Lid

my thought was to use a strip of neoprene as a gasket around the edges. Should compress enough to keep it sealed.

Daniel
1981 Nor'sea 27,
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Quote:
“Who is staring at the sea is already sailing a little.”
-Paul Carvel
Rhapsody-NS27 is online now  
Quote Quick Reply Share with Facebook
post #6 of 13 Old 1 Week Ago
Senior Member
 
midwesterner's Avatar
 
Join Date: Dec 2015
Posts: 498
Thanks: 6
Thanked 17 Times in 17 Posts
Rep Power: 2
 
Re: Rebedding Water Tank Lid

Quote:
Originally Posted by Hudsonian View Post
Use PTFE gasket on a roll, which provides soft, highly compressible gasketing. You'll find it at McMaster-Carr or plumbing suppliers who deal in flange to flange piping. Select tape approx 1/3 the width of the flange. PTFE gasketing does not support bacterial growth and is FDA compliant for water and food service.
This would sound like the best idea and option.
midwesterner is online now  
Quote Quick Reply Share with Facebook
post #7 of 13 Old 1 Week Ago
Senior Member
 
svjobeth's Avatar
 
Join Date: Nov 2008
Location: Marathon, FL
Posts: 231
Thanks: 7
Thanked 14 Times in 13 Posts
Rep Power: 9
 
Re: Rebedding Water Tank Lid

Quote:
Originally Posted by Hudsonian View Post
Use PTFE gasket on a roll, which provides soft, highly compressible gasketing. You'll find it at McMaster-Carr or plumbing suppliers who deal in flange to flange piping. Select tape approx 1/3 the width of the flange. When compressed the two sealing surfaces are torqued down it provides a very wide, thin ribbon-like joint sealant and it fills the irregularities on rough or uneven surfaced flanges. PTFE gasketing does not support bacterial growth and is FDA compliant for water and food service.
As part of our refit on JO BETH, our 1984 Crealock 34, we replaced all of the tank lids, (water tanks and holding tank), with new fiberglass lids from Pacific Seacraft. The original lids were epoxy painted wood and were essentially disintegrating.

We considered PTFE for the lid bedding, but in the end, went with an industrial food grade silicon, the same stuff used to seal truck tanks carrying cooking oils, milk, potable water, etc. So far, so good, with around 1,000 miles sailed. The manufacturer name escapes me. It came in a standard caulk gun size tube and we ordered it through McMaster-Carr. If I can find the name, I'll post it.

Bill & Lisa Ballard
S/V Jo Beth
1984 Pacific Seacraft Crealock 34, Hull #16

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


"Twenty years from now you will be more disappointed by the things you didn't do, than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover."
- Mark Twain

Last edited by svjobeth; 1 Week Ago at 03:46 PM.
svjobeth is online now  
Quote Quick Reply Share with Facebook
post #8 of 13 Old 1 Week Ago
Senior Member
 
Join Date: Jan 2007
Location: The house is in Kingsport, TN. Boats are on Watauga Lake and in New Bern, NC
Posts: 407
Thanks: 4
Thanked 52 Times in 47 Posts
Rep Power: 11
 
Re: Rebedding Water Tank Lid

I used "GE 100% Silicone Sealant for Plastic Sheets and other Plastic" in a red and white tube to bed the gray PVC cover for my holding tank. It was what they had at Lowes with the pexiglass on the day that I needed it and the label said "for Plastic". It has not leaked in years.

Bill Murdoch
1988 PSC 34
Irish Eyes

Last edited by wsmurdoch; 1 Week Ago at 08:09 PM. Reason: spelling
wsmurdoch is online now  
Quote Quick Reply Share with Facebook
post #9 of 13 Old 1 Week Ago
░░░░░░░░░░
 
Join Date: Apr 2006
Posts: 12,402
Thanks: 6
Thanked 184 Times in 181 Posts
Rep Power: 13
   
Re: Rebedding Water Tank Lid

Silicone was probably used because it is on every shelf and folks think it is the greatest stuff on earth. Of course if it is "bathtub caulk" grade, it contains arsenic to prevent mildew, not the best thing for a water tank.

Food grade silicone, neoprene, teflon...many ways to skin a cat. You might check with PermaTex or LocTite to see if they make a "Form-A-Gasket" sealant for water tanks. That's a product that is similar to silicone seal (to the casual user) but you apply it to a surface, like the edges of an oil pan, and then bolt it up and let it cure. At which point it becomes basically a custom made gasket, designed to be compatible with the fluid it has been used with.

I would think that tightening all the screws to a *very* similar torque would be more important, in the long run, than the specific gasket material. If you pick up a cheap "foot inch" 1/4" torque wrench, even the $10 ones from Horror Fright, that can give you a fast way to match them all up. Or use an electric drill/driver that has adjustable light torque settings, and use that.
hellosailor is offline  
Quote Quick Reply Share with Facebook
post #10 of 13 Old 1 Week Ago
Senior Member
 
Join Date: Jan 2007
Location: The house is in Kingsport, TN. Boats are on Watauga Lake and in New Bern, NC
Posts: 407
Thanks: 4
Thanked 52 Times in 47 Posts
Rep Power: 11
 
Re: Rebedding Water Tank Lid

Quote:
Originally Posted by hellosailor View Post
S Of course if it is "bathtub caulk" grade, it contains arsenic to prevent mildew, not the best thing for a water tank.
Do all bathtub caulks contain leachable arsenic as a mildewcide? I did not see it listed on the SDS for the GE products that I found on-line.
wsmurdoch is online now  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 4 (2 members and 2 guests)
degkc , svjobeth
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Atlantic Marine Hot Water Tank and Fresh Water Winterization Dcneuro Gear & Maintenance 5 12-17-2012 11:03 AM
Converting water tank to diesel tank - fittings? Zanshin Gear & Maintenance 5 09-15-2009 05:38 AM
Smelly water from fresh water tank Bruce_Olson Gear & Maintenance 20 09-01-2007 04:42 PM
Refrigeration -Using the water tank as a cooling water source HenryRusty Gear & Maintenance 7 03-29-2007 12:14 AM

Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome