Ply Clinker (Lapstrake) Frames

[MarkWoyWoy]

Hello All,

I've just turned over a small launch I'm building in glued ply lapstrake.

This is my first boat and is built from a table of offsets and a line drawing. It is round bilged and will use a small hit and miss one lunger.

My question is to do with frames. I have decided that five laminated frames(one at each station) should be ok. However should I take these all the way up to the sheer or to the edge of the plank above the waterline or something else?

Insofar as the frames go should I install these before the inner wale(I will be using spacer blocks) or after?

The boat is a little bit flexible at the moment. Unfortunately I cannot use the molds to stiffen the boat up as it was built using Tom Hill's stringer method. I currently have a few notched 2 x 4's holding it in shape.

Thanks in advance,

Mark S.

[EdenRose]

Mark,
I just flipped my glue lapstrake over a few weeks ago. Built according to T Hill also.
It was a floppy boat until I put the gunwale/sheer clamp
on the outside. Then with each frame it gets stiffer.
Your design should specify which stations get frames. Out of 8 stations on my boat, a fairly round Swampscott 16' dory, only three get frames. The thwarts add a lot of support too.
They should run up to the sheer, as T Hill
shows on page 95. Mine connect at sheer
and chine log on bottom. I am going to notch
in between the inwale and sheer plank and, like you, I am using spacers between inwale and plank.
What boat are you building?

[G. Schollmeier]

Here are two pictures of a glued lapstrake pulling boat with frames. This is not ply but will give you a look at one approach .

http://www.boatdesign.net/gallery/showphoto.php?photo=282&papass=&sort=1

http://www.boatdesign.net/gallery/showphoto.php?photo=284&papass=&sort=1

Gary

[ 09-24-2002, 01:11 AM: Message edited by: G. Schollmeier ]

[JimConlin]

I'm stunned.

[G. Schollmeier]

I should say this is not my work. If I could do that I wouldn't hanging out here. ;)
Gary

[Jack Heinlen]

Mark,

You say small, but tell us more.

In small rowing craft of this sort a gunwhale to gunwhale laminated frame, integral with the longest thwart is often considered enough.

Given the motor, I should think a series of two or three partial frames(essentially floors), tied into the motor mounts, along with something gunnel to gunnel, tied into a midship thwart structure, would be enough.

If you've got the savvy to build this from plan, you probably have a fairly good sense of scantlings. Trust your intuition and then up it 15 or 20 percent. Depending on usage.

Jack

[MarkWoyWoy]

Thankyou,

I was doing a few other things last night and I think I've answered my own question. It would seem to me that the inner wale should be done before the frames.

A bit of trial fitting shows that the inner wale will tend to move the sheer outwards by about 1/4' at the center of the boat. If I have frames in first then I'm concerned about this movement trying to pull things apart.

That's a nice boat.

Jack the idea of upping 15% or so is good. Given the motor and that I want the boat to look sort of traditional I think I will run the frames up to the sheer.

As far as the boat goes it is a 10-11ish foot launch for inboard power. It's a Weston Farmer design called the Irreducible.

I will post some pictures when I can find my camera.

Thanks again

Mark S.

[gert]

I think I just saw perfection. Please refrain from showing this level of work on this site for we are mere mortals, I think I have been blinded. Totaly inspiring. Click on "see all of Uli's photoes"

[ 09-24-2002, 07:58 PM: Message edited by: gert ]