Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 01-06-2012, 10:25   #16
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: Bulkhead Scarf

Quote:
Originally Posted by Cheechako View Post
I like the idea of using two 3/8 thick pieces glued together with the joint in different places.
or...I might make a rabbet joint the full depth of the table saw blade I have, overlapping the two pieces. Then glue and clamp flat out side of the boat (can you get that into the boat?) No reason a 4" overlap joint with proper glue shouldnt be as strong as any other part of the plywood is there?

Scarf joints are recommended over lap joints for a reason. With bulkheads you usually need to do the joint in the boat, or you'll never get it in. I would not do either a lap or staggered butts, but to each their own...
__________________

__________________
minaret is offline   Reply With Quote
Old 01-06-2012, 10:32   #17
Senior Cruiser
 
Blue Stocking's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,117
Re: Bulkhead Scarf

Quote:
Originally Posted by minaret View Post
Scarf joints are recommended over lap joints for a reason. With bulkheads you usually need to do the joint in the boat, or you'll never get it in. I would not do either a lap or staggered butts, but to each their own...
The sheets of plywood are made with butted veneers.
Scarfs were originally developed to join solid lengths of material where a difference in grain conditions could exist with in the contacting surfaces, and to allow bending ability to take place.
But--like you said, to each his own.
__________________

__________________
so many projects--so little time !!
Blue Stocking is online now   Reply With Quote
Old 01-06-2012, 10:52   #18
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,777
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Bulkhead Scarf

i need to do this in my after portion , at the bulkhead for galley and battery containment and mast supporting blocks--have supported my mizzen, next it dig outthe fridge remnants and re beam and bulkhead repair.. did bow--wasnt too bad---used regular marine ply with lots of penetrating epoxy--will do same in after portion. the mahogany problem is why i have to do this--phillipine mahogany rots like pine. ouch....now to find a locale in which to destroy and remake my boat...lol
zeehag is online now   Reply With Quote
Old 01-06-2012, 11:58   #19
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: Bulkhead Scarf

Quote:
Originally Posted by zeehag View Post
i need to do this in my after portion , at the bulkhead for galley and battery containment and mast supporting blocks--have supported my mizzen, next it dig outthe fridge remnants and re beam and bulkhead repair.. did bow--wasnt too bad---used regular marine ply with lots of penetrating epoxy--will do same in after portion. the mahogany problem is why i have to do this--phillipine mahogany rots like pine. ouch....now to find a locale in which to destroy and remake my boat...lol

Good luck, Zee, were rootin for ya!
__________________
minaret is offline   Reply With Quote
Old 01-06-2012, 12:38   #20
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,777
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Bulkhead Scarf

got her so it is workable for a coupla yrs max--so i have bought some time on her--we shored up some parts, and i am seeking wood.. fun this boating thing..LOL..i love it!
zeehag is online now   Reply With Quote
Old 01-06-2012, 14:42   #21
Registered User

Join Date: Apr 2006
Location: Port Clinton, Ohio
Boat: C&C Landfall 35 HiHo
Posts: 112
Re: Bulkhead Scarf

One other option is to use bisquets. From the picture it looks like you could aslo add a backer on the forward side of the bulkhead fro the hull out past the joint and stop just inside of the face of the cabinet. If you are working with something more than 1/2" stock such as 3/4" you could use the full lenghth rabbet joint as suggested. with expoy doesn't take a much clamping so doing inside the boat is not that bad.
__________________
Hi Ho is offline   Reply With Quote
Old 01-06-2012, 14:46   #22
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: Bulkhead Scarf

Quote:
Originally Posted by Hi Ho View Post
One other option is to use bisquets. From the picture it looks like you could aslo add a backer on the forward side of the bulkhead fro the hull out past the joint and stop just inside of the face of the cabinet. If you are working with something more than 1/2" stock such as 3/4" you could use the full lenghth rabbet joint as suggested. with expoy doesn't take a much clamping so doing inside the boat is not that bad.

Seriously? Biscuit joining a bulkhead? And I mocked the lap joint...
__________________
minaret is offline   Reply With Quote
Old 01-06-2012, 15:11   #23
Registered User

Join Date: Apr 2006
Location: Port Clinton, Ohio
Boat: C&C Landfall 35 HiHo
Posts: 112
Re: Bulkhead Scarf

I only suggested this because it is not a structural bulkhead and if he can back the joint up as discriped he will have a very solid joint. His boat manufacturer used a butt joint, my C&C Landfall was built the same way with the main bulkhead with nothing more than a glued butt joint. On my C&C the bulkhead joint did not fail but it did rot out. I replaced mine 6 years ago with bisquets in the joint and there has been no movement in the joint on my 1/2" thick bulkhead
__________________
Hi Ho is offline   Reply With Quote
Old 01-06-2012, 15:22   #24
Senior Cruiser
 
Blue Stocking's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,117
Re: Bulkhead Scarf

Quote:
Originally Posted by Hi Ho View Post
I only suggested this because it is not a structural bulkhead and if he can back the joint up as discriped he will have a very solid joint. His boat manufacturer used a butt joint, my C&C Landfall was built the same way with the main bulkhead with nothing more than a glued butt joint. On my C&C the bulkhead joint did not fail but it did rot out. I replaced mine 6 years ago with bisquets in the joint and there has been no movement in the joint on my 1/2" thick bulkhead
Dont worry Hi Ho, its easy to become a legend in your own mind around here.
One of the problems with the internet is that one never knows whom one is criticizing.
__________________
so many projects--so little time !!
Blue Stocking is online now   Reply With Quote
Old 01-06-2012, 15:29   #25
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,777
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Bulkhead Scarf

i would do what minaret sed in a heartbeat--he is smart. fixes lots of big bux boats....
zeehag is online now   Reply With Quote
Old 01-06-2012, 15:40   #26
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: Bulkhead Scarf

Quote:
Originally Posted by Blue Stocking View Post
Dont worry Hi Ho, its easy to become a legend in your own mind around here.
One of the problems with the internet is that one never knows whom one is criticizing.

Hey, I'm not criticizing anyone, just criticizing biscuit joining a bulkhead, as I'm sure many other's would. As I already said, to each their own. I was brought up to scarf a bulkhead, and it's such an easy joint to make I can't imagine why you wouldn't. But I'm sure there are as many other opinions on that as there are people who make a bulkhead. Seem's like you are the one criticizing people, what's your problem?
__________________
minaret is offline   Reply With Quote
Old 02-06-2012, 09:37   #27
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,201
Images: 52
Re: Bulkhead Scarf

Quote:
Originally Posted by Blue Stocking View Post
Dont worry Hi Ho, its easy to become a legend in your own mind around here.
One of the problems with the internet is that one never knows whom one is criticizing.



Oh, now you've got nothing to say? Don't feel like explaining yourself? Wutta pansy...
__________________
minaret is offline   Reply With Quote
Old 02-06-2012, 09:52   #28
Pusher of String
 
foolishsailor's Avatar

Cruisers Forum Supporter

Join Date: Feb 2007
Location: On the hard; Trinidad
Boat: Trisbal 42, Aluminum Cutter Rigged Sloop
Posts: 2,314
Images: 19
Have to agree with minaret. A scarf joint is not just about joining different grains it is also about increasing the gluing surface, and more importantly preventing the issues associated with the point of contact between materials with vastly different properties glue and wood. One is brittle and one is not, even if one uses better wood glues versus epoxy.

A butt joint even one that is glued like a resawn frame is a point of failure as there is a "sudden" change in the material properties along with minimal gluing surface. A scarf allows a gradual change in properties along with a large glued surface. A vastly superior solution.

There is no reason to fear a scarf joint. One can build a scarf jig and use a hand or power planer to make the scarf, even a relative wood novice can do it. Google scarf jig and see how easy.

Just cause many in the industry use butt joints and epoxy doesnt make it right, in fact it is the opposite of right. Epoxy catastrpohically fails when placed in a situaion where there is high frequency flexing
__________________
"So, rather than appear foolish afterward, I renounce seeming clever now."
William of Baskerville

"You will do foolish things, but do them with enthusiasm."
Sidonie Gabrielle Colette
foolishsailor is offline   Reply With Quote
Old 02-06-2012, 10:27   #29
Pusher of String
 
foolishsailor's Avatar

Cruisers Forum Supporter

Join Date: Feb 2007
Location: On the hard; Trinidad
Boat: Trisbal 42, Aluminum Cutter Rigged Sloop
Posts: 2,314
Images: 19
Quote:
Originally Posted by Blue Stocking

The sheets of plywood are made with butted veneers.
This is not comparable as the but joints exist in what 5 to 15ayers depending on thickness? This is effectively a single layer.

I would disagree with minaret somewhat on the biscuit joint. Biscuits are crap but FesTool makes a great joiner that produces a structural superior joint not using biscuits but there own almost dowel like plug. You will still have potential issues on the asthetics of the join but it will be structurally sound.

Scarf is still better
__________________
"So, rather than appear foolish afterward, I renounce seeming clever now."
William of Baskerville

"You will do foolish things, but do them with enthusiasm."
Sidonie Gabrielle Colette
foolishsailor is offline   Reply With Quote
Old 02-06-2012, 10:42   #30
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,777
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Bulkhead Scarf

i thinki would not want to trust the repairs ineed to do in my formosa to biscuit joints-- thre is way too much weight supported by this combination of bulkhead and support blocks to warrant anyhting besides a scarfing....i may add a nice i beam to the mix for peace of mined.....
__________________

zeehag is online now   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 13:34.


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.