stringer rules...how many and where???

Questions about boat repairs with our resins and fiberglass: hull patches, transoms and stringers, foam, rot etc.
Saltfix
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stringer rules...how many and where???

Post by Saltfix »

rebuilding a fiberglass boat that HAD a web fiberglass stringer system..
Replacing with wood stringers.....
boat has four chines.. chines inside are the only "flat " place inside the now eggshell of a hull.
Is that where I should run my new stringers?
It will also get frames of course and I read somewhere stringers and frames should meet at the chines..so ..
Does that sound like the Idea?
Run the stringers the full length of the four chines and instal frames?
22 ft boat so the flour sections will be 4' the width of the plywood sheets..
frames every 4' doubled for the ends of the plywood and additional ones between comes to frames every 2'
Transom is already in ....but wanted to get some input before proceeding with stringers....
Thanks.

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cape man
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Re: stringer rules...how many and where???

Post by cape man »

A pic or two would help. Hard to add too many stringers 8)
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fallguy1000
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Re: stringer rules...how many and where???

Post by fallguy1000 »

Is this the '79 Kencraft?
My boat build is here -------->

viewtopic.php?f=12&t=62495

TomW1
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Re: stringer rules...how many and where???

Post by TomW1 »

What is the width of the deck at the top of the stringers? That will also help us and no they don't necessarily have to be at the chines, they should be evenly spaced as they are the driving force of the boat, and you want it evenly driven by the transom. I question the need of frames every 2' even in a fiberglass hull. At least not full frames. A 3-4" intermediary frame attached to the stringers on the bottom and running to the deck would be plenty to prevent hull tin canning.

Looking forward to your build.

Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

Saltfix
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Re: stringer rules...how many and where???

Post by Saltfix »

how do I post pics? I cant seem to find a button that will let me post from my computer..

OneWayTraffic
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Re: stringer rules...how many and where???

Post by OneWayTraffic »

Just underneath your post window should be an attachments tab. I find that the easiest way myself. Some use a 3rd party service and post links.

Most glass trailer boats will have two stringers each side of the keel on the bottom. If the keel has a decent deadrise angle of about 10 degrees or more then that would be a stiffener as well, as would the turn of the chine to the hull sides. Then the attachment of the sole to the sides stiffens that assuming that it’s glassed in. Important that the stringers are well bedded everywhere and securely tabbed in. By ‘chines’ I assume you mean sprayrails on the bottom. These also stiffen the hull.

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Re: stringer rules...how many and where???

Post by TomW1 »

Jeff, could you help him on posting pictures, I cannot seem to find the instructions tonight. Tom
Restored Mirror Dinghy, Bought OD18 built by CL, Westlawn School of Yacht Design courses. LT US Navy 1970-1978

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Re: stringer rules...how many and where???

Post by Reid »

Posting pictures works best when your pictures are downloaded on your computer.
Once you have the dialog box open (big white window you type in) follow these steps:
1) Click on the attachments tab below
pics 1.PNG
2) Click "Add Files"
pics 2.PNG
3) Select the picture(s) you want to upload and "open" those files
pics 3.PNG
4) One at a time, put your cursor where you want the picture to appear in the dialog box and click "Place Inline". You will then see a line of code where the picture will eventually show up.
pics 4.PNG
pics 5.PNG
5) Once you have done this for all of your photos, click the "Preview" button below and scroll up to see your post. Once you are satisfied click "Submit"

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Attachments
pics 2.PNG
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Saltfix
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Re: stringer rules...how many and where???

Post by Saltfix »

is it a good idea to use a router to round the edges on the bottom of stringers to eliminate sharp edges before you bond them with the epoxy putty?

OneWayTraffic
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Re: stringer rules...how many and where???

Post by OneWayTraffic »

I wouldn't say that it's needed. Most important is to have an even bond everywhere with no areas of high pressure. Some use popsicle sticks or little pieces of foam to keep the stringer slightly off the hull while the putty sets up. The stick can be removed later, no big deal if a little piece gets stuck under.

Edit: You could use a single pass with a grinder or sander to slightly round just the corner that makes more contact with the hull if you like (side further from the keel.) Might save a little bit of putty by allowing you to have the stringer sitting a bit lower. Don't see that it's really important.

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