Closed cell foam for stringer core?

exp2000

Petty Officer 2nd Class
Joined
Dec 10, 2009
Messages
148
I am thinking of following:

1. Cutting the tops of the stringer
2. Taking all the wood out, leaving glass in tact
3. Filling voids with a closed cell foam
4. Adding an 1'' thick wood at the top of the stringer so that floor can be screwed
4. Glass over the everything with epoxy so it would stick to previous poly glass

Does this sound like a good idea or is it stupid?
 

Bondo

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Apr 17, 2002
Messages
70,464
Re: Closed cell foam for stringer core?

Does this sound like a good idea or is it stupid?

Ayuh,... I guess it'll depend on whether it's an 8' Dingy, or an 80' Cruiser...
 

exp2000

Petty Officer 2nd Class
Joined
Dec 10, 2009
Messages
148
Re: Closed cell foam for stringer core?

Oh, it is 16 foot BL.
 

Bob_VT

Moderator & Unofficial iBoats Historian
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May 19, 2001
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26,019
Re: Closed cell foam for stringer core?

bad idea........

You need the strength of the stringers. Regardless of the density of the foam it will not be strong enough.
 

Spinnaker

Petty Officer 1st Class
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Jul 5, 2009
Messages
210
Re: Closed cell foam for stringer core?

As long as you use core-cell foam. You can use core-cell in place of wood anywhere. Even better results if vacuum bagging. It is way much lighter and the strength is incredible. Pricey though. You would not have to glass wood into the top as core-cell will take screws. In fact, you don't need screws. Just weigh the floor down and use structural putty to adhere the floor to the stringers. With the floor glassed around the outside it's not coming up again.
I wouldn't leave the glass shell after removing the old wood from your stringers. You are just trying to save time and effort. You'll end up with air pockets unless you use a lot of structural putty and clamping, even then you're adding a lot of weight. It's just not the proper way of going about it to cut corners.
 

exp2000

Petty Officer 2nd Class
Joined
Dec 10, 2009
Messages
148
Re: Closed cell foam for stringer core?

Do I have to grind and remove all poly from the whole hull or can I just grind it like 6 inches on both sides of the stringer?
 
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