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Tom M.
01-03-2008, 12:36 AM
On the heels of the rivet how to thread...

Ok, now that we know how to rivet, how about advice on when to rivet? Specifically, I have questions on fastening carvel planking to frames on a 30 foot cruiser (future build). I realize almost all carvel builds these days use bronze screws without apparent problems. However, it appears rivets have some compelling advantages, such as no problems with screw threads pulling out due to rot or excessive tension, etc. There's also the possibility, if the head is not countersunk, that the full strength of the plank can be utilized (countersinking and bunging means you lose perhaps 1/3 of the plank thickness where its fastened.)

-Are these real advantages in practice?
-How does a riveted hull look? (nail head, not pyramid head) Is it ugly?
-Can a rivet be countersunk and bunged? Do rivets need to be re-peened over time due to crushing wood fibers?
-Do rivets seal as well as screws? Is it a disadvantage to drill thousands of holes in your hull?

Dave Gray
01-03-2008, 12:49 AM
Tom, my impression is that carvel built hulls are riveted if they are lightly framed, which means there is not enough meat to properly hold a screw. As to drilling holes for rivets, you would be drilling the same holes for screws so I can't see where that makes a difference. I've not heard of countersunk bungs or rivets. But then what I know comes from books, not from doing, so hang on and someone who knows what he/she is talking about will be sure to expound on the topic.

Jay Greer
01-03-2008, 11:08 AM
Both of Larry Pardey's boats are rivited as well as my own Common Sense Sloop "Red Witch". The 38' Alden Schooner "Wanderlue II"
Was built in 1927 and fastened with galvanized boat nails that were clinched. The 59' Seawhanhaka schooners were all copper rivet fastened as well as the Ten Meter "Sally" to name a few. All of these boats had the fastening heads bunged over. NG Herreshoff invented screw fastening for yacht construction in order to speed up production of his boats. He also contended that the screw has less tendency to loosen up on boats that are placed in winter dry storage.
Jay

mike hanyi
01-03-2008, 01:47 PM
my new boat to build I have the same debate

screws- dambed fast and can be done alone
slightly more expensive, but saves time
the teeth of the screw can over time cause cracks in the
frames in tight radiuses possibly due to the screws only
holding in a percentage of the frame. difficult to refasten the
boat

nails and rivets- mostly requires 2 people, fatigue on both people in
wrist.
if built upsidedown very difficult to the point of
impossible.
my opinion- is there is less stress on the frames as
the holding power is on the rove,at the surface of the
frame, so the entire frame is taking the load, sheer
strength is also taken completly in the frame,
refastening is much simpler,remove rove and drive it
out.


there are plus and minus to both, I have not yet decided for myself either.

mike

Bob Cleek
01-03-2008, 02:19 PM
About the only difference between the two is that when you are finished riveting, nobody says, "Call me in the morning."

Tom M.
01-03-2008, 10:43 PM
Both of Larry Pardey's boats are rivited as well as my own Common Sense Sloop "Red Witch". The 38' Alden Schooner "Wanderlue II"
Was built in 1927 and fastened with galvanized boat nails that were clinched. The 59' Seawhanhaka schooners were all copper rivet fastened as well as the Ten Meter "Sally" to name a few. All of these boats had the fastening heads bunged over. NG Herreshoff invented screw fastening for yacht construction in order to speed up production of his boats. He also contended that the screw has less tendency to loosen up on boats that are placed in winter dry storage.
Jay

Thanks for this good info Jay.

Tom M.
01-03-2008, 10:45 PM
my opinion- is there is less stress on the frames as
the holding power is on the rove,at the surface of the
frame, so the entire frame is taking the load, sheer
strength is also taken completly in the frame


Yes, this makes sense. Thanks for pointing it out.