Key West again

Designs for inboard or outboard power

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gostap
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Key West again

Postby gostap » Mon Jun 26, 2017 1:16 am

Hello;
A question from a confused newbie.
I am planning to build the Key West and now I have start the project and order and received the full pattern plans.
However, there is something I don’t understand about the patterns of the frame members.
The pattern show the outside shape and form but not the inside? So, I am confused which width and contour of the members to be. Also, according to the instruction there is bottom member and side member but the pattern show whole member. So I suppose it is meant to be “cut off” but where?
See attached sketch.

Thanks in advance!

//Gostap
Attachments
members.jpg

Mark-NJ
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Re: Key West again

Postby Mark-NJ » Mon Jun 26, 2017 2:59 am

Speaking only for me, I did "neither" of those cuts. Instead, I did half-lap joints.

I built a router jig out of scrap, and set up each piece for proper cutting

Image

The results were pretty good!

Image

I just figured that the superior strength of a half-lap over a butt joint was worth it.

I know this isn't really an answer to your question, and for that I apologize. But just so you know there's a 3rd option...

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gostap
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Re: Key West again

Postby gostap » Mon Jun 26, 2017 4:05 am

Thanks for you answer;

I not sure what you mean with half lap joints?
Unfortunately I cant see you image

gostap

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DrBryanJ
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Re: Key West again

Postby DrBryanJ » Mon Jun 26, 2017 4:12 am

Gostap: I would make the side pieces the full length and bring the bottom piece to meet the inside of the side frame. Doing that, you will not have to fair end grain later in the build. As for width, did you read through the directions. Maybe it is mentioned in there?

Bryan
Bryan

Building a malahini "Mona Lisa"

My wife said "If I build a boat, she's getting a divorce."

TomB
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Re: Key West again

Postby TomB » Mon Jun 26, 2017 4:38 am

Gostap,

Also have a look at the smaller drawings, probably sheet 2 for frame info. There will also be a Frames section in the instructions.

Tom

slug
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Re: Key West again

Postby slug » Mon Jun 26, 2017 6:10 am

The usual procedure is to butt the joints and use plywood gussets glued and screwed to join the corners/pieces. It will be in the plans somewhere.

Doug

ToddM
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Re: Key West again

Postby ToddM » Mon Jun 26, 2017 8:05 am

I don't have access to the Key West plans, but the instructions to the Tahoe cover the questions you are asking, but in relation to the Tahoe of course. My assumption is that some of your answers for the Key West are in the instructions and on the plan sheets. It just so happens that I am presently reading the chapter of, "Boatbuilding with Plywood", with the frame joints explained in detail.

All that said, on the Tahoe, the inside contour of the curved frames is the outside contour minus 3 inches; 3 inches being the width of the frame. The Tahoe plans do not show the "cut off". So, I am in the process of drawing each joint where I think the "cut off" should be. Half lap joints are not recommended by Glen-l, with the reason given being that when screwing into the edge seam of the joint, the screw will have less holding power. Personally, I disagree. I prefer screwing into the epoxy seam rather than the solid wood and think that screwing into an epoxy joint is stronger than screwing into solid wood. But, that is a personal opinion based completely on my own bias and having no basis in fact that I know of. The drawback to using a half-lap joint is that one half side of the surface to be screwed into will be end grain and screwing into end grain is definitely weaker than screwing into crossgrain, so in the places where a half-lap joint is used, there will have to be some accommodation for screwing surface.

Bottom line, you probably are not going to get a direct answer on which method to use on which joints, and you will probably have to do some research on when different options are used and you will have to make your own decision. I recommend buying, "Boatbuilding with Plywood."

And don't feel dumb if you have no idea what the different joints are. I noticed that the plans don't list all the things and parts needed to make the boat go, steer, get tied up, etc.. And I have no idea what the boat needs to make it behave like a boat, rather than a piece of furniture.

PeterG
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Re: Key West again

Postby PeterG » Mon Jun 26, 2017 8:44 am

The Key West at 22' or so and almost 8' wide is a big, beautiful boat, a worthy project!
I have noticed at least with Ken Hankinson designs that the full size patterns only give the outside edges of frames and transom. That is not a problem, you just have to manually lay out the interior edges of the frame pieces.
The information you are looking for is in the drawing sheets where the frames are shown. I highly recommend getting the Glen-L book Boatbuilding with Plywood. I read the entire book, re-read it, and when I thought I had absorbed it all, I read it again. It is on my workbench in my shop too. It covers all of the steps and processes you need to build your boat with more detail (and plenty of example photos) than the drawings and patterns will have. You will do best if you can draw the frame lines full size on a sheet of plywood, or a couple sheets or a wood floor... it's a big boat. Draw the setup line, then the centerline, and use transfer paper (carbon paper, Glen-L sells it in an convenient size) with the patterns to draw the frame lines on the plywood. You can use this full size "drawing" on the plywood to make templates of your frame pieces. You can compare them to the lines when fine-tuning their shape, and you can align them in place when you build your frames.

Post lots of pictures of your build, we all want to see your project!
Murphy's Law: Anything that can go wrong, will go wrong.
Griffin's Law: Murphy was an optimist.

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Bill Edmundson
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Re: Key West again

Postby Bill Edmundson » Mon Jun 26, 2017 9:03 am

You can use half laps if you want. But, I would recommend the gussets anyway.

Bill
Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

slug
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Re: Key West again

Postby slug » Mon Jun 26, 2017 10:46 am

I first cut all my frame pieces out of good quality cardboard ( you plywood supplier uses it as cover sheets so they should have lots of it scrapped ) then transfer them to the lumber (usually 3/4" by 3"0, except on the curved pieces.
Doug

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Roberta
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Re: Key West again

Postby Roberta » Mon Jun 26, 2017 1:47 pm

I used the full lap with a gusset in between the frame members on the Zip. The deck beams are typically a full lap with a bolt and not a gusset. On the Torpedo, I used the butt joint with gussets on both sides of the joint. Dr B is correct to make the side member longer to avoid screwing into the end grain when fastening the chines. Any of the three methods will work fine. Pick the one you are most comfortable doing. As Bill suggested, use the gussets on the half lap to give a wider landing area and more strength for the chines, especially on larger boats.

Roberta :D
Attachments
stringers laminated 003.JPG
Butt joint with two gussets sandwiching joint
Zip frames 002.JPG
Full lap with center gusset
Roberta "Queen of the Boat Builders"
Built Zip "Oliver IV", Super Spartan "Jimmy 70", and Torpedo "The Glen L".

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gostap
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Re: Key West again

Postby gostap » Tue Jun 27, 2017 7:38 am

Dear boat builders!

I am really grateful for all answers, now i have something to think about :)

What an excellent forum this is!

Mark-NJ
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Re: Key West again

Postby Mark-NJ » Tue Jun 27, 2017 11:16 am

Thinking is good.....but don't get overly lost in the weeds. Eventually you just need to decide "I'm doing it THIS way" and move forward.

I remember asking questions when I was starting out: What kind of wood should I use? or What kind of joint should I use? or "What kind of glue should I use? etc.

The answer was often, "I don't know...it's not my boat, it's yours!" Even a few books I read offered that sentiment.

At first, I found that just a little off-putting, but as I got deeper into things I started to see the truth in it. Boats have been built for thousands of years, and the set of "hard & fast rules" is pretty short. Find your stride....you'll be fine!

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Andy Garrett
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Re: Key West again

Postby Andy Garrett » Sat Jul 01, 2017 8:57 am

For that boat: I'd choose single gusset full lap joint or the double gusset butt joint as Roberta pictured for you.

You could go for a routed half lap joint with double gussets for what might be optimal strength, but be sure to cut the bottom member a bit short to keep any end grain away from the sides as previously mentioned. I think this would amount to over-engineering.
Andy Garrett

Perhaps the slowest Zip build in Glen-L history...

PeterG
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Re: Key West again

Postby PeterG » Sat Jul 01, 2017 6:18 pm

Honestly I would stick to the per plan method, the half lap joint is good for increasing glue area but is more or less a weaker joint because of the thicknesses and useable grain of the two pieces being reduced by half. It is a slightly more complicated joint to fit up versus a butt joint reinforced by plywood gussets. Realistically, that joint design has proven over the years/decades to be plenty strong enough. :D
Murphy's Law: Anything that can go wrong, will go wrong.
Griffin's Law: Murphy was an optimist.


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