extremely odd stringer system... what to do? Help please

metalmanbc2000

Seaman Apprentice
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Jul 13, 2009
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I started to gut my floor today and found that I have fiberglass stringers. before i started to tackle this job i looked around on the website at floor repair and couldn't find anything like this. the stringers are completly cracked and rotten and have zero strength left in them. I was wondering if anyone has encountered this before and what the best plan would be.
 

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tallcanadian

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Re: rotten, cracked fiberglass stringers... what to do

Re: rotten, cracked fiberglass stringers... what to do

They are strange looking things. Are they solid fiberglass or is there wood in there as well? Looks like you may have to grind them even at the floor and rebuild new ones with wood then glass them in.
 

metalmanbc2000

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Re: rotten, cracked fiberglass stringers... what to do

Re: rotten, cracked fiberglass stringers... what to do

The are hollow fiberglass. Nothing really to them. i was thinking the best route was to maybe take them completly out like you said and reglass them but i don't want to comprimise my hull by removing them. then i thought that i would run wood strigers either side of the existing glass ones then reglass the whole thing.
 

boatflipper

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Re: rotten, cracked fiberglass stringers... what to do

Re: rotten, cracked fiberglass stringers... what to do

Looks like a couple of 2x6's should have been layed down flat on top of each other and glassed in! Any ideas what you are going to put in them? Wood or pourable compound like sea-cast would work good.
 

metalmanbc2000

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Re: extremely odd stringer system... what to do? Help please

I decided to cut out the old inneffective and poorly designed fiberglass stringers and start on a traditional wood one today. got the rest of the floor out and test fitted the first two stringers. everything seems to be going ok.
 

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micks110

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Re: extremely odd stringer system... what to do? Help please

I think you made the right choice to remove and start over. Make sure you coat the wood stringers with poly first to seal them before you put them in and glass them just for piece of mind.
 

reelfishin

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Re: extremely odd stringer system... what to do? Help please

What brand boat are you working on?

I've run across a few odd types of stringers or supports over the years, the strangest was cardboard covered in fiberglass. I've also seen a few done with balsa wood with a glass covering. The wood or paper rots away and they appear to be hollow.
In the early days of fiberglass there were many different companies experimenting with various ideas, some good, some not so good.

I would guess that when they built your hull the goal was to save weight and they formed those stringers around something that has either rotted away or they were formed over a mold and set in afterward.
 

metalmanbc2000

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Re: extremely odd stringer system... what to do? Help please

the top portion of the stringers had a half inch plywood in them but the supporting uprights had nothing it seems to me like whoever built this stringer system was thinking about weight and definetly not longevity. everything was cracked and degrated. a thin fiberglass can obviously not withstand a beating over the years. i did a lot of research looking for a stringer system that was close to mine with no luck. so i figured that i would gut it and put something traditional in. it seems to be working so far i have the boat gutted and the stringers in and everthing seems fine. thanks for all the advice guy's i appreciate it alot. My boat is a k&c thermoglass. it was a company based out of richmond B.C. that went out of buisness. i love the look of the boat and am happy that i am restoring it and it will last another 20 years
 

tallcanadian

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Re: extremely odd stringer system... what to do? Help please

Do you have any pics of the boat itself? Would love to see it.
 

jspano

Senior Chief Petty Officer
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Oct 30, 2009
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790
Re: extremely odd stringer system... what to do? Help please

you should try to insert your photos in the post, more people will look at them and you might get more input... just my opinion

boat20005.jpg
[/IMG]
 

mikastorm

Petty Officer 2nd Class
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Aug 16, 2009
Messages
164
Re: extremely odd stringer system... what to do? Help please

Cut your stringers out and get some ruff cut oak. Very reasonable.
Sheet over with your resin . You are back in business.
Lumber mills will set you up for your thickness. Ask for old timber to use.
My stringers on my 14 ft. Larson where gone and this is what I did.
That boat was so stong you could have doubled the hp rating.
 

chuck in WA

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Aug 3, 2004
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Re: extremely odd stringer system... what to do? Help please

Is there something "wrong" with the current stringers? I'm far from an expert in this area, but IMO if the stringers really were designed and built hollow, then one would think that the engineer took strength into account. As a previous poster stated, if the fiberglass was laid up over a cardboard tube or some other such expendable product, the strength comes from the fiberglass "I-beam" itself, not from what the fiberglass is constructed around. Unless the fiberglass is damaged/delaminated/etc, I wouldn't be quick to tear it out. Maybe contact the manufactuerer and ask about the original design?

Of course, if the stringers are also the engine mount, then you may have a case to replace....
 

metalmanbc2000

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Re: extremely odd stringer system... what to do? Help please

the stringers were completly messed up. They were formed around some half inch plywood that was completly rotted out. They were cracked and falling apart so i removed them. there was no way to keep them in there that i could tell and i honestly think it was a **** poor design to start with. i have the new wood stringers cut and ready for a coat of resin. I'm thinking about putting some pour foam in the voids between the new stringers. there was no foam in the boat originally, i was wondering if that was a good idea or will it change what the boat does in the water.
 

tallcanadian

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Re: extremely odd stringer system... what to do? Help please

If you want foam use it. It will give more strength to hull and the deck. I think the route your going is fine. For sure your stringers will be stronger and coated in fiberglass they should last longer than what is in there now.
 

F14CRAZY

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Re: extremely odd stringer system... what to do? Help please

I'm with chuck. If there's truly nothing in there then it must have been engineered that way.

With wood-core stringers, I mean I'm not a marine engineer but it seems that the wood is mostly just there to lay up the fiberglass "beam"
 
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