Help with stringers!!

[drewmitch44]

Man im having a hard time with these things!!! I dont have the old ones to use as template and i used string to go from side to side and measured from the string down to the middle of the cavity. I took the measurements and i put it on the wood and it did not work right!!! I still had the bow and stern touching and the middle of the boat with a foot of space between the hull and the bottom of the stringer. I used string going from side to side every 10 inches and i thought i measured right but i guess not!!! Im having such a hard time! Can anyone help me out? Im going to lowes now to get some aplience boxes i guess so i can do it with cardboard. But man im having such a hard time with this!!!!! I spent 6 hours putting those strings up and it did not work! I cant believe it. And i wasted a good piece of wood too and all the time to prep it just so see that it was WAY off!!! help me out here guys! Thanks!

 

[erikgreen]

Re: Help with stringers!!

Post some pics or a diagram of what you did.

Oops can probably help, he's scratchbuilt stringers recently. Have you read his hull extension thread?

Erik

 

[Smokin'Mo]

Re: Help with stringers!!

You should be running the string lines longitudinally along the top edges of where the old ones were. If you can determine where the old stringers attached to the transom, you can run string line from those points to the front of the boat keeping the string flush to the underside of the floor (or where the floor would be). When you get to the bow section, make sure the floor cut-out has an original bit remaining for you to attach your string lines to. It should be fairly evident where the old stringers ran along the hull, so use this as a guide when running your string lines. Once you have 2 string lines stretched for each stringer the process of measuring comes begins. Mark each string line in 6" increments starting from the transom. When you get the the other end you're done. You can start measuring the distance from the string lines to the hull at each 6" increment. I found the best way to achieve any accuracy was to use a level with a measurement scale on it which ensured vertical level when measuring down from string line to hull (this is lots of work but worth it). When all measurements have been recorded you can now transfer them onto cardboard for test fitting. After all of that you can finally transfer onto your laminated ply (or whatever you use) pieces and shape the stringers to the traced lines. The shaping process is lots of work as well but again, when you secure those stringers to the hull, there should be no errant protrusions in your stringers causing hard spots. When bedded to the hull with either PL or Peanut butter, the gap thickness between stringer and hull should be pretty uniform.

 

[mspring]

Re: Help with stringers!!

The carboard idea is where I am at this point. Lumber is exspensive so I am not cutting plywood without a template.

Remember the only place your stringers have to be perfect is at the top where the deck will rest on top of them. As far as the bottoms of the stringers you know you dont want the wood touching the hull. So they dont have to be perfectly fitted there in fact 1/4 to 1/2 of an inch is desirable in order to give the hull the room to flex that it needs.

You have your string lines, cut them close enough on the bottoms then shim them up until the top is level with strings, then fill the gap at the bottom with the PL caulk that tashasdaddy uses. Then go down the bead of caulk with a spoon to round it off. It will hold the stringers in place, hide the gap, and the rounded bead will make it easier to glass in with no air bubbles.

 

[drewmitch44]

Re: Help with stringers!!

I have done stringers a couple of times before with the PL Poly construction adhesave. I dont usually use a spoon but a blank CD-r to shape the PL to the contour that i want and then run another small bead down the center to help it a little. But my problem this time is i have no stringers to use as a template. I put my strings up from port to starb. and not bow to stern. So you are saying my strings should go from bow to stern? If thats the case how do i account for the sag in the middle? Just about any string, nylon, or just about anything i can think of will sag in the center! I cant think cause of all the numbers in my head! I took the measurements off the way that i did it (side to side) and i applied it to a piece of 1X12X12' lumber and when i put in the boat it did not make any sence! There was a huge gap in the center of the hull where the ends touched at the bow and stern then there was like a 6" gap in the center between the hull and the stringer. Man im dumb and i cant figure it all out. I can see where the edges of the deck is supposed to be all around the hull. Also i can see where the stringers are supposed to sit on the hull from bow to stern. Help me out here!

 

[oops!]

Re: Help with stringers!!

hey andy....

the post and scribe method in the hull ext thread is very simple...

if you need more explanation you have my phone number.

another way, is a to make a cardboard template......


also remember......the stringer does not touch the hull....so it does not have to be perfect......rough will do.....

you just bed it any how..... right...

some times we over think this stuff so much.......

the early boat builders were not rocket scientests, and did not walk around in lab coats with micrometers........

they guessed at half the stuff !......kinda like....gee... it looks like we need wood there....so they put wood there......

forget the side to side string line....youll kill your self with the math......

just get the general shape of the hull as close as you can.....once they are bedded and in....you can cut to desired deck height.

cheers
oops!

 

[drewmitch44]

Re: Help with stringers!!

yea but im having problems with getting the contour of the hull! Thats ****ty. I have done 5 other stringer jobs and i had the old stringers as a template. The previous owner of this thing has some 2X6's in there with shims in the places where the stringers did not touch the hull. And they only had 2 stringers running the legnth of the hull. Thats it. No others! There is supposed to be 4 running the legnth. And the bow part is raised and im not raising it on this rebuild but eather way i got no templates. I cant believe that i ran this boat that way for a whole summer. The hull is about 1/2 inches thick of just glass. I cant believe how thick the hull is! Im still trying to put the stringers how they were. Where the bow hook goes through the hull the glass is 3/4" thick of origional fiberglass. I cant believe that! I did stringers on a couple of Gayliners and the glass is thin as all get out. This sea ray is no joke as far as the hull that is why i decided that it is going to be my boat! Like i said i have done this a couple times before but not from scratch. Thanks oops!

 

[drewmitch44]

Re: Help with stringers!!

I cut that board with a jig saw and it was soooooooo wrong. I wanted to put a bullet in my head. Now i got some applience cardboard from lowes to make cardboard templates out of. THen i dont have to waste any more wood. Thanks!!!! I need help!

 

[Coors]

Re: Help with stringers!!

Cardboard is cheap.
Did you see the thread we had going, about how to get it close, then use a spacer and pencil, to exactly trace the hull to the pattern?
get a block of whatever, with pencil on top, then run it along the hull contours, transferring it to the pattern.
Cut the pattern, put it in the hull, then use a string on top, to find how much to add to the height all the way across it.

 

[redfury]

Re: Help with stringers!!

You can always run strings from the front to back and side to side to support the string if you want to take measurements. If you wanted to get technical, you can always mark the string in 6 inch increments along the length of the boat and measure the heights that way, but you'll want to use a plumb bob to make sure you are measuring exactly below that line, and make sure the hull is level.

I'm going to be doing the same thing once I get ready to do stringers as the originals didn't just "come out". They came out alright, about 6 inches at a time, so I'm in the same predicament. The only thing I've got going for me is that the fiberglass tabbing is still there....I should take some measurements before I get to cutting them out....

 

[oops!]

Re: Help with stringers!!

Cardboard is cheap.
Did you see the thread we had going, about how to get it close, then use a spacer and pencil, to exactly trace the hull to the pattern?
get a block of whatever, with pencil on top, then run it along the hull contours, transferring it to the pattern.
Cut the pattern, put it in the hull, then use a string on top, to find how much to add to the height all the way across it.

imho....this is one of the easyest ways to do it andy..........


hey guys ....did you read this?

http://forums.iboats.com/showthread.php?t=249010

read eriks responce ...#9.....i choked on my burger it was so funny