glassing over removed thru hull. what glass to use? - SailNet Community
 1Likes
Reply
 
LinkBack Thread Tools
post #1 of 17 Old 04-04-2017 Thread Starter
Junior Member
 
Join Date: Jan 2017
Location: florida
Posts: 24
Thanks: 13
Thanked 0 Times in 0 Posts
Rep Power: 0
 
glassing over removed thru hull. what glass to use?

I have removed a 2 inch diameter thru hull fitting in my fiberglass sailboat. The hole is underwater and the hull is ½ inch thick at that point.

My main question is regarding the type of glass I should use in making this patch. I will be using West System epoxy.

I have seen much info about doing such a repair, but what fabric exactly I should use remains a question. I would like to make the repair as strong as possible.

Some say use 1708. Some say 1708 with mat, some say 1708 without the mat. Some say 12 oz cloth would work.

My guess is that most any fabric would work, but I have to choose one. I do have confusion over chopped strand mat. I know there is the stitched type that would be compatible with epoxy. But is the CSM necessary?

If I had to do it right now, I would use 1708 with no mat….

I feel confident in my ability to lay up the glass from both the inside and the outside. The inside does not have as much room for tapering the patch, but I can still do some lay up.

So what fabric should I use?? Please, thank you!!
lost soul is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 04-04-2017
Senior Member
 
amwbox's Avatar
 
Join Date: Aug 2015
Location: Portland, OR
Posts: 632
Thanks: 23
Thanked 34 Times in 34 Posts
Rep Power: 5
 
Re: glassing over removed thru hull. what glass to use?

Alternating between mat and cloth will most closely resemble the original layup schedule. If your boat was made with a chopper gun, your repair might be the strongest part of the entire boat.

Fiberglass Repair by Don Casey - BoatTECH - BoatUS
seabeau likes this.

"Freedom is the increased knowledge of what you can do without." —Thoreau
amwbox is offline  
post #3 of 17 Old 04-04-2017
Senior Member
 
Join Date: Jun 2016
Location: (sail mostly on) Lake Belton, TX
Posts: 286
Thanks: 1
Thanked 26 Times in 26 Posts
Rep Power: 4
 
Re: glassing over removed thru hull. what glass to use?

Mat has a binder agent which doesn't dissolve properly in epoxy so use heavy cloth layers rotated appx 45 degrees each layer so the fibers run in the many directions which is one of the main points of using mat.

I like to build thickness with heavy cloth, then the last few layers go to finer and finer cloth so the weave is finer resulting in a smoother surface 9less sanding)
Turnin Turtle is offline  
 
post #4 of 17 Old 04-04-2017 Thread Starter
Junior Member
 
Join Date: Jan 2017
Location: florida
Posts: 24
Thanks: 13
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Re: glassing over removed thru hull. what glass to use?

Thanks guys,

I sure hope Tartan did not build my boat with a chopper gun!!!

From what I see and read, there is a stitched mat that is compatible with epoxy. but I dont think I want to use any mat anyway.

Maybe I will go with 12 oz cloth? or just biaxial. Or 17 oz?

what to use is my only question...
lost soul is offline  
post #5 of 17 Old 04-04-2017
Catalina 400 MKII
 
Scotty C-M's Avatar
 
Join Date: Aug 2013
Location: Santa Cruz, California
Posts: 814
Thanks: 8
Thanked 72 Times in 68 Posts
Rep Power: 7
 
Re: glassing over removed thru hull. what glass to use?

I have a question. Is the hull epoxy or polyester? If it is poly, why not use polyester resin for the patch?

Thanks, Scotty
Scotty C-M is online now  
post #6 of 17 Old 04-04-2017
Senior Member
 
Faster's Avatar
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 19,488
Thanks: 160
Thanked 587 Times in 558 Posts
Rep Power: 17
     
Re: glassing over removed thru hull. what glass to use?

Epoxy provides a much better secondary bond than polyester onto old fiberglass.. however a proper patch done with either would likely be just fine. Using Polyester (or better, Vinylester) would make alternating layers of matt a decent choice. I have used 1708 biax (stitched matt included) with epoxy resins with some success - but it won't 'wet out' clear like polyester will.

Tapering the hole and layering in the largest patch first is the way to go whichever materials are used.

Ron

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Faster is offline  
post #7 of 17 Old 04-04-2017 Thread Starter
Junior Member
 
Join Date: Jan 2017
Location: florida
Posts: 24
Thanks: 13
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Re: glassing over removed thru hull. what glass to use?

The hull is poly with a vinylester outer laminate. It was peeled and relaminated due to a
'washed out" outer laminate.

I would only use epoxy as it is superior in adhesion and strength. Being an amateur I will take any advantage I can. The increased cost is not much, especially compared with failure.

boat is a Tartan 34, 1974
lost soul is offline  
post #8 of 17 Old 04-04-2017
Dirt Free
 
boatpoker's Avatar
 
Join Date: Jul 2008
Location: Toronto
Posts: 2,611
Thanks: 22
Thanked 147 Times in 142 Posts
Rep Power: 12
 
Re: glassing over removed thru hull. what glass to use?

For such a small patch, the weight and weave is irrelevant. I'd use whatever was in the back of my truck at the time. Use 6oz. if you like and keep laying it in with epoxy til' hull thickness is matched. If the rest of the job is done properly you'll have no trouble.

The hysterical laughter you hear as you drive a way in your"new" boat ..... is the seller.
boatpoker is offline  
post #9 of 17 Old 04-06-2017
Senior Member
 
Join Date: Jun 2001
Posts: 671
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 19
 
Re: glassing over removed thru hull. what glass to use?

If you use epoxy you may have issues getting the gelcoat to stick. Then again you could also put INTERPROTECT over it and then bottom paint. Just say'n.
sailordave is online now  
post #10 of 17 Old 04-06-2017
Dirt Free
 
boatpoker's Avatar
 
Join Date: Jul 2008
Location: Toronto
Posts: 2,611
Thanks: 22
Thanked 147 Times in 142 Posts
Rep Power: 12
 
Re: glassing over removed thru hull. what glass to use?

Quote:
Originally Posted by sailordave View Post
If you use epoxy you may have issues getting the gelcoat to stick. Then again you could also put INTERPROTECT over it and then bottom paint. Just say'n.
Sand it, clean it, two part primer & gelcoat will adhere quite nicely but why would anyone put on gelcoat below the waterline ?

The hysterical laughter you hear as you drive a way in your"new" boat ..... is the seller.
boatpoker is offline  
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











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Glassing a old wood hull. Agri Sailboat Design and Construction 24 07-17-2012 09:33 AM
Glassing over old through hull openings jaschrumpf Gear & Maintenance 23 07-08-2009 02:56 PM
Glassing hull GreenEarth General Discussion (sailing related) 18 06-20-2009 12:52 AM
Newbie glassing over a thru-hull squishface Gear & Maintenance 9 03-07-2009 12:07 AM
Glassing Hull GreenEarth Gear & Maintenance 0 06-24-2001 04:13 PM

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

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