Catalina - Capri - 25s International Assocaition Logo(2006)  
Assn Members Area · Join
h.jpg Home.
a.jpg Association Forum
s.jpg Ships Store
c.jpg Cruising
r.jpg Racing
t.jpg Technical Tips
g.jpg Photo Gallery - New
o.jpg Boat Search - Updated
m.jpg Manuals & Brochures
3rdrpt.jpg Swap Meet
l.jpg Links
f.jpg Officer Flag Line & Staff
b.jpg Bylaws & Constitution
 
1.jpg Members Area
1.jpg Join the Association
 
Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
 
Association Forum
Association Forum
Home | Profile | Register | Active Topics | Forum Users | Search | FAQ
Username:
 Password:
Save Password
Forgot your Password?

 All Forums
 Catalina/Capri 25/250 Sailor's Forums
 Catalina 25 Specific Forum
 Through hull		  New Topic  Topic Locked
 Printer Friendly
Author Previous Topic Topic Next Topic  

Jay Schkloven
1st Mate

Member Avatar

USA
84 Posts
Initially Posted - 10/16/2004 :  14:22:15  Show Profile
I have a through hull that needs to be rebedded or replaced. I will not know for sure until I take the old one out. Can I use exterior grade plywood as a backing, life chalk as the sealer,and how tight should I tighten the new brass through hull? Then I will tighten it to make a find seal when the chalk cures. Any help would be appreciated.
Jay
Edited by - on

ClamBeach
Master Marine Consultant

Members Avatar

3072 Posts
Response Posted - 10/16/2004 :  15:02:42  Show Profile
If you're using plywood as backing, I'd be sure to epoxy saturate it first. Water and plywood don't play well together.

"how tight should I tighten the new brass through hull?"

That's a hard one to answer as it depends a bit on 'mechanical feel' and experience. The best description I can come up with is 'just snug' which means you've taken all the slack out of the system.. at that point, bedding should be have flowed out all around the seating area... but some should be remaining between the fitting and the hull (just a little bit).

The next step in my tightening schedule is 'firm'... again, very much based on experience...

I prefer 3M 101 below the waterline... IMHO a bit thicker and more robust than lifecaulk... but that's just one guy's opinion.
Edited by - on
Go to Top of Page

John V.
Admiral

Members Avatar

USA
559 Posts
Response Posted - 10/16/2004 :  20:48:51  Show Profile  Visit John V.'s Homepage
Ditto the epoxy soak...Cut your epoxy with a bit of xylene. It will soak in better. As for the bedding, I would use 4200, hand tighten and let it cure for 24 hours. Then tighten up fully. If you tighten all the way while the goop is still uncured you will squeeze out most of your seal and when there is a stress to the hull or during winter storage the seal may be broken. You want to be sure that there is a good gasket formed before you tighten home.
Edited by - on
Go to Top of Page

OJ
Master Marine Consultant

Members Avatar

USA
4382 Posts
Response Posted - 10/16/2004 :  22:41:11  Show Profile
Jay,
For what it's worth, I found the thickness of the C25 hull in the areas of the thru-hulls to be quite adequate. If you do use a plywood backing, I'd drill an oversized hole - allowing the Life Caulk to form a gasket all the way upto the securing nut.
I waited a week before I applied the final torque . . . now that the cooler weather is hear I'd give it even more time.
One extra step I took when I converted to thru-hulls - I drilled an oversized hole and filled it with an epoxy/filler mixture. When you re-drill the original size hole, this will leave a ring of epoxy/filler to protect the fiberglass laminate from any moisture that might migrate in over the years.
Good luck!
Edited by - OJ on 10/19/2004 22:21:43
Go to Top of Page

Oscar
Master Marine Consultant

Members Avatar

USA
2030 Posts
Response Posted - 10/16/2004 :  23:24:29  Show Profile  Visit Oscar's Homepage
Quite the range on waiting time before final torque, there is in fact a large range of cure time depending on what kind of goop you're using. When in doubt read the label...

Oscar
C42 # 76 "Lady Kay" (Formerly C250 WB #618)
Edited by - on
Go to Top of Page

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts
Response Posted - 10/17/2004 :  00:11:46  Show Profile
If you use a plywood (or other hard material) backing, round the corners and bevel the edges that meet the hull.
Edited by - on
Go to Top of Page

jwilliams
Captain

Members Avatar

USA
357 Posts
Response Posted - 10/20/2004 :  12:37:27  Show Profile
Jay,

I just finished a bottom job and replaced the to-hull with a thru-hull.

I found that the thickness at the site was built up with fiberglass to approximately 3/4 inch in addition to the hull thickness.

It was uneven, so after sanding it level I filled with MarineTex, then resanded to insure the site was flat. I used a felt tip pen on the bottom of the nut to trial level, as the nut would leave a trace of black where it touched the surface of the site. Sanding until the site was equally touched, i.e. level.

I used Boat Caulk on both ends, set it finger tight so the goop squeezed out. After curing overnight, I tightened the nut on the new, flat site.

No leaks after a week.

Funny, tho, I thought the original hull fitting was supposed to be 1/2in. Mine was 3/4. And the valve was a Marelon Ball type. Which I replace with a new one.

Jim Williams
Hey Jude C25fk 2958
SF Bay
Edited by - on
Go to Top of Page

OJ
Master Marine Consultant

Members Avatar

USA
4382 Posts
Response Posted - 10/20/2004 :  22:07:27  Show Profile
FWIW, my galley drain is 3/4" and the head sink drain is 1/2".
Edited by - on
Go to Top of Page

Todd Frye
Navigator

Members Avatar

USA
222 Posts
Response Posted - 10/21/2004 :  19:02:14  Show Profile
Lots of good advise. I have been using High Density Polyethylene for my backing plates. It cuts, mills and sands well, using ordinary woodworking tools. I round over my edges with a router and it takes epoxy and 5200 nicely. All my new thru hulls have HDPE backing plates as well as O.B. bracket, stanchions, swim ladder, etc. Your local plastics supplier should carry this stuff. If you do “resize” your new thru hull holes, make sure to seal the hole edge with epoxy to guard against any seepage that may get past your outside seal. Good luck. Todd Frye
Edited by - on
Go to Top of Page

Dave Bristle
Master Marine Consultant

Members Avatar

Djibouti
10005 Posts
Response Posted - 10/21/2004 :  20:17:27  Show Profile
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jwilliams</i>
<br />I used Boat Caulk on both ends, set it finger tight so the goop squeezed out. After curing overnight, I tightened the nut on the new, flat site.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
That's the right technique to form a compressed gasket, except I've found that overnight doesn't let the unexposed caulk cure very well, and it will try to squeeze out when you tighten down the fixture. 2-3 days is probably better--the cooler, the longer.
Edited by - on
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Topic Locked
 Printer Friendly
Jump To:
Association Forum © since 1999 Catalina Capri 25s International Association Go To Top Of Page
Powered By: Snitz Forums 2000 Version 3.4.06
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.