By McKenzieDriftBoat.com
Whitewater decking
I'm preparing for the decking for a Briggs style Grand Canyon Dory. Do all of the tops of the frames (vertical ribs) need to be cut so the decking sits on top of them? Or, do they poke through and continue to the sheer rail as on an un-decked boat? Thanks for any insight - Joe
Views: 198
Replies to This Discussion
-
Permalink Reply by Robb Grubb on -
Joe,
I am at the same point you are with my decked / framed boat. I plan to cut out the plywood decking material (3/8 thick) around the vertical ribs. This will be pain staking, however I am thinking that the vertical ribs need to remain for the structural integrity of the boat.
Regarding plywood deck fitting, I am going to split the plywood down the middle of the boat left and right halves. This hopefully will ease the 'fitting' pain and allow some room for error that I can trim later in the middle of the boat.
I have a decked boat I built 14 years ago and the compartment / seal at the sides of the boat have been the least of my worries. Patients when measuring / cutting and 5200 does the trick. I used 3/4 x 1/2 inch fir material for framing support on the insides of the boat where the deck lays on in between the ribs and that fir seems to bend with the boat sides pretty good.
I am only going to oil the wood inside the hatches. Hopefully this will allow the wood to breath and not trap water.
What type of hatch / latch / hinge ideas are you planning on?
Regards,
Robb Grubb
www.RiverTraining.net
-
Permalink Reply by Joe Dengler on -
Great input Robb. The deck split in halves makes alot of sense. Jeff Peak sent me this link for latches http://www.southco.com/class/c5-sealed-lever-latches-7381.html
He felt they were worth the expense.
The ribs adding structure also makes sense yet I see all of these S&G boats without any frames and hoped I could save the extra challenge of cutting around them.
Did you epoxy and glass the seal at the hull?
-
Permalink Reply by Robb Grubb on
-
Joe, On my 16' Don Hill, The only thing I did on the deck to hull (side) seal was stainless screws, 5200, epoxy resin and over the years, lots of paint. I have never had a leak in these areas.
I have had leaks where the bulkheads meet the floor of the boat, it has been an on going issue for the 14 years I have had the boat. This boat is not totally decked (just one compartment up front and one in back) so the rain and waves have access to the bulkheads. I think with all the flexing and hits in a framed boat the seals take their toll.
Regarding the side ribs going to the gunnel, I hear what you are saying. I assume S&G boats have so much resin and cloth encapsulating the sides, it adds more strength. I would be leary not having ribs going all the way to the gunnels on a basic framed boat. I am also considering cutting some of the ribs down (#1, #5, #7 on a 9 rib boat) to make the compartment building easier, but have not decided for sure. I am going to keep the ribs going to the gunnel around the oarlocks for sure.
Cheers,
Robb Grubb
www.RiverTraining.net
-
Permalink Reply by Joe Dengler on
-
Ok, unless I hear a good argument against it I'll error on the side of strength for now. Still working on hatches today and this weekend and on to bulkheads and decking by next if all goes well. I appreciate your advice.
-
Permalink Reply by Jim Rubino on -
Hi Joe, you can see pics of my stitch and glue boats that have seen more whitewater than most of the boats posted here since I've had the Briggs dory down the grand canyon on 5 previous trips and several other whitewater runs These boats have plywood bulkheads instead of frames and I think there is no structural loss between the top of the deck and the gunnels. Seems it would be a lot easier to cut the decking without having to work around the frames.
Best, Jim
-
Permalink Reply by lhedrick on -
Jim is right.
I'm not saying you should or should not cut the top of the frames but strength won't be an issue. The deck seam and gunwales are more then enough. just do whatever you like and don;t worry about it. 3 of the bulkheads on my boat aren't even plywood.
On a rebuild I once removed the front deck on a fishing boat. It was held in place with epoxy fillets. The would not brake loose with a hammer. I had to use a 2 inch chisel along the fillet seam to get them off. Then it took a grinder to clean off the remaining epoxy. A Briggs boat is a heavy boat so keep the weight down whenever possible. I use 1/4 inch plywood on the decks these days with glass on top. With the deck sitting on top of bulkheads it's fine. On one or 2 places I epoxied a braces under the deck just to reinforce a spot which would flex when I would stand on it. I am 220 pounds.
-
Permalink Reply by Brad Dimock on -
The ribs continue through and are bolted to the gunwales. That's what adds so much strength to your gunwales and the boat in general. Old Jerry Briggs said the most painstaking part of decking was cutting around the damned frames. Once they were in place he laid a thick cotton twine along the joint and applied a 2" fiberglass joint tape. That was the only fiberglass in the whole boat.
As some of the posts below indicate, it is probably overkill. A Briggs was built as a ribbed open boat, which is plenty strong without decking. The new ribless epoxy boats get their strength from the bulkheads. The decked Briggs has both. But in the end, it is worth it.
The testament is the fact that out of 36 Grand Canyon boats Briggs built from 1971 to 1982, all but one are still operable. Mine is a 1972, has well over a hundred Canyon trips and a great deal of rough, upper basin use, has been wrecked mightily a few times, but still runs Grand Canyon regularly.
-
Permalink Reply by Ukulady on -
How do you think the boats with bulkheads stack up against the Briggs with the bolted ribs in terms of longevity?
-
Permalink Reply by Brad Dimock on
-
It's really hard to tell, since all of them get good care and seem to be immortal. The ones with ribs seem to be a bit more of a pain to work on in a big crash scenario. And when you're fitting decks, painting, etc. they are a project to work around. But I have this retro love for the look of a framed boat as opposed to the newer WEST ribless boats. Probably the same reason that I far prefer the look of a transomed boat. The classic Briggs is the first dory I rowed and pretty much the only boat I rowed from the late 70s 'til now, growing from adolescent to crusty.
-
Permalink Reply by Jeremy Christensen on -
I think you should leave the ribs in place. For me it worked better to break up the decking into several smaller pieces, putting them together like a puzzle around the framed hatch openings, instead of trying to do one or two large pieces. Then just faired the seams and it came out great.
Brad, that's amazing. My boat is headed to Lees for it's first trip down in March.
-
Permalink Reply by Brad Dimock on
-
I should add, lest I mislead anyone: only a couple of the original Briggs boats that still run are still un-fiberglassed. Most of them have begun a slow Frankenboat transition to being WESTified. Some have undergone ribectomies. Mine now has a foam/WEST floor but is otherwise all wood--exterior is fiberglassed. But it still runs great and will be doing two Grand Canyon trips this year.
Jeremy--congrats on getting her ready for a Grand trip. Hope it's somewhere in the middle ground between uneventful and traumatic. Just remember--they're as much fun to fix as they are to build. And a good boatman can get one through intact, but a great one can tear it in two, fix it, and come out smiling.
-
Permalink Reply by Joe Dengler on
-
Thanks everyone for the thoughtful insight. This remains a super fun project with learning at every turn. I'm Jammin to finish by a March 25th put-in. Thanks again! Joe
© 2012 Created by Randy Dersham.
