PDA

View Full Version : Carvel vs. strip



cs
11-08-2002, 06:43 AM
Let me see here in carvel the planks are attached to the frames and in strip the strips are attached to each other.

Now if you convert a carvel design to strip and say you decided not to reduce the number of frames. Example: My friendship plans call for frames @ 9"c/c with carvel planking. I'm no thinking about stripping the boat and leaving the frames on 9"c/c.

What would be the best way to do this? Should I build the boat on mold and than put the frames in? If so how would you fasten the frames to the hull? Would you screw through the strips or would you epoxy them in? Or should I build every frame and attach to the keel and than start stripping?

I'm still aways off from starting this project, but every question addressed now will help set me on the correct path. I still need to find a book and learn how to loft.

Chad

On Vacation
11-08-2002, 07:20 AM
Chad, I will share this comment with you on this question. Think about doing a plywood jig first to set up the boat. This will give you patterns for cutting more expensive and harder woods before you end up with a potential waste and a lot of filling sometimes of glue and or wood. Time and money well spent for the first time rib-frame builder. This is money in the bank.

[ 11-08-2002, 08:23 AM: Message edited by: Oyster ]

imported_Conrad
11-08-2002, 12:55 PM
Get a hold of Dave Gerr's newest book, "Boat Strength". With some simple math you can both see how the designed scantlings stand up to current engineered standards, and also work out appropriate scantlings for any alternative construction method. Using his engineering training, traditional scantling rules, and a historical perspective of what has worked and what hasn't, he's work out easy to use rules for all types of construction. It's excellent!

On Vacation
11-08-2002, 03:09 PM
Thanks, I will look at it when I start my new strip plank hull.
http://www.imagestation.com/picture/sraid15/pa37c8c64ee67c5aa41aff79cef4ffac1/fde67ef4.jpg

John Bell
11-08-2002, 04:03 PM
Guess you're not stopping by tonite, are you Erster... :(

cs
11-08-2002, 04:03 PM
I'm defintly going to look at that book. If I build the boat on a plywood jig and than put in the frames how do you fasten the frames?

Chad

On Vacation
11-08-2002, 04:04 PM
I sent you an e-mail. My sever stinks. The trip is postponed till two weeks. I will venturing but going the opposite direction. We are going to pick APPLES. ;)

John Bell
11-08-2002, 04:08 PM
Well you are welcome anytime. Lori will be disappointed.

On Vacation
11-08-2002, 04:10 PM
Chad, you true up the boat form on the plywood jig and then take patterns off and cut the frames and any ribs you will need. Then you screw through the sides of the plywood into the frames to hold them in place and screw the strips to them. This is what I was going to get to io the next step of lofting out full size with plywood.

The form will be very simular to the bulkheads that you did for the Bateau boat. Relax and leave the driving to us. If you have not done a full rib frame boat, most of the time a person will use and waste good wood in the attempt to cut the frames out/ This is whay I suggested this way.

cs
11-08-2002, 04:35 PM
I think that I follow what you are saying. You want me to loft the forms and attach the frames to this (temporally) and than attach the strips to the frames. Once this is done take the temp. forms out. Now with frames every 9" do I need a form for every frame?

I was thinking of bulding temp. forms and stripping to these and than adding the frames. Once the frames are added I would remove the temp forms.

BTW as far as I can tell these frames are bent rather than sawn.

Chad

On Vacation
11-08-2002, 04:58 PM
Chad, when I get back I will give you a call about the frame deal. You can do the jig and down size it to accept the frame deminsion and tack it to the jig and then do the strips to that. I take it that this bilge is round chime. Were you planing on stem bending? I am not sure of the configuration. Up foward you will need to shave an angle on the jig before you apply the frames.

Joe (SoCal)
11-08-2002, 09:41 PM
Originally posted by Oyster:
I sent you an e-mail. My sever stinks. The trip is postponed till two weeks. I will venturing but going the opposite direction. We are going to pick APPLES. ;) I got yer Apples rite here oyster smile.gif

JimD
11-08-2002, 10:12 PM
Chad, I've just started a strip plank 22 footer. the hull is built upside down on a building form made out of 2x6s. Frames will be laminated from about 10 1/4 inch strips or sawn. The sawn frames are mounted on 3/4 inch plywood bulkheads. The frames/bulkheads are lined up upside down on the building strong back using the waterline as a convenient reference point to make sure they are set up correctly. The laminated frames that do not have substantial bulkheads to define them are bent onto jigs made from the cheapest plywood, osb, etc, because once the strips are laid on and the hull is complete the temporary jigs are removed and tossed, leaving only the frames.

Another nice thing about strip planking is that the keel is easier to make, no rabbet necessary for the garboard. The keel is just a plain board that the frames sit on and the strips are laid on and faired flush to the keel board
jimd

cs
11-11-2002, 01:58 PM
JimD you're building the Amigo, right? How close together are your frames? Will you have to build a form for every frame?

Oyster waiting for your call.

Chad

JimD
11-16-2002, 12:29 AM
Chad, sorry to take so long getting back to you - been outta town for a few days. The Amigo frames are about 2 feet apart, so from stem to stern there are about 10 of them in the 22 foot boat. Each frame will either have a permanent bulkhead of marine ply or a cheapo mold to be removed after stripping, so every frame will be supported during stripping to ensure correct hull shape. As for scantlings the frame widths taper and are thicker at the sheer, tapering down towards the keel where they are reinforced by substantial plywood floors. Stock measurements for the frames are minimum 1 1/4 wide. The depth is about 3 inches at the sheer tapering to 1 1/2 at the keel. The strips called for are 3/4 inch, so I will build with closer to one inch to allow plenty of room for fairing.

What is the spacing and frame scantlings for the plans you have?
jim

cs
11-19-2002, 06:36 AM
Jim my plans call for frames every 9" and they are 7/8" x 1-1/4". The planking called for is 3/4" thick.

I talked with a reputable builder off line and he since I was doing it in strip and using Doug Fir instead of cedar that I could take the frames as far apart as 18" c/c. I probably wont go that far but I am playing around with every 12".

Don't know for sure yet as I'm still stuyding the plans. I also plan on getting Dave Gerr's book that Conrad mentions above.

Chad

JimD
11-19-2002, 11:06 PM
Chad, interesting...your frames are designed for steam bending, I assume, so they are thinner so they can be more easily bent, and closer together to compensate for the thinness and to prevent movement. The Amigo frames are over twice as far apart but much heavier. They don't have to be close together because the strips are edge glued so not much can shift, work, and wear. What's the keel / keelson setup look like? I'd imagine the keel has a rabbet for the garboard.jimd