# Layup schedule for Honeycomb board decks



## loud_by_design (Mar 21, 2013)

Hey everyone, I am about to embark on the rebuild of an old johnsen skiff and plan to use honeycomb board in the link below for the core material of the decks. for now I am trying to figure out if id be better off using 1/2" or 3/4" for the decks and bulkheads. Id like to keep bracing in the form of bulkheads to a minimum to optimize space and planned on using 3/4" because of this but wonder if 1/2" would be enough. Also ive seen some people claim that a single layer of 1708 on each side is enough while other keep stacking the glass on. I was thinking a layer of 1708 on each side and then one or two layers of 6oz woven top and bottom as well as another layer of 6oz on top if need be. The areas I will be rebuilding will be the front and rear casting deck and obviously will need to support a person as well as a yeti that I use for a casting platform. thanks in advance.


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## DuckNut (Apr 3, 2009)

Can't say if 1708 will be enough because you don't tell us how far the span will be.

Also no link found for the board.

Honeycomb is great for flat horizontal surfaces but it is not designed for a vertical carrying a load.

If you buy honeycomb, buy the one with glass preattached


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## loud_by_design (Mar 21, 2013)

The largest span on the front deck will probably be 24" by 50". I have a bunch of scrap 1x1 mahogany pieces from another project and was wondering if I could use those as a support frame underneath the deck and glass them in but I'm not sure if it would work plus they're pretty heavy.
Here's a link to the board http://www.fiberlay.com/prod-core-materials.php?subclass=406025-4066150&startrow=0


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## riptide (Dec 31, 2009)

I like two layer top and bottom and any support on the under side will pay off in the stiffness of the deck.
In the awkward places I like to tear some fiberglas mat to help it lay flat or bending around hard corners


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## riptide (Dec 31, 2009)

oh and use the 3/4


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## CurtisWright (May 9, 2012)

I used 1/2 core on mine with a 1 1/2 oz Matt and 24oz biaxial on each side and they are plenty strong. 60" span from gunnel to gunnel


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## yobata (Jul 14, 2015)

Are you using poly resin instead of epoxy? Just an FYI, Jacques at boat builder central made a pretty good point once: even though poly is cheaper you end up using much more of it because of the need for mat in between layers of biax, and in the end spend about the same but end up with a heavier product compared to epoxy. If you are trying to save weight by using composite cores, why not also use epoxy and then just 17oz biax (or even 12oz) without the need for the 8oz mat in the underside of it which soaks up much more resin... 1708 is 17oz biax with an 8oz mat (required for poly preparations whereas epoxy does not need a layer of mat in between).... This is my understanding of layup schedules based on a thorough conversation with him...


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## loud_by_design (Mar 21, 2013)

For now I planned on using poly since it is $80 per 5 gallons instead of $70 per gallon for epoxy. The main reason I was going for honeycomb instead of wood was to avoid any potential rot issues in the future. Also I found a place to get the orca honeycomb for less than a sheet of 1/2 marine ply so that doesn't hurt either. If possible saving weight on this skiff would be great but its not the main goal of this build.


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## Mercuryproteam (Aug 20, 2015)

loud_by_design said:


> For now I planned on using poly since it is $80 per 5 gallons instead of $70 per gallon for epoxy. The main reason I was going for honeycomb instead of wood was to avoid any potential rot issues in the future. Also I found a place to get the orca honeycomb for less than a sheet of 1/2 marine ply so that doesn't hurt either. If possible saving weight on this skiff would be great but its not the main goal of this build.



Where did you find the orca honeycomb cheap. Getting ready to re do a skiff as well.


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## loud_by_design (Mar 21, 2013)

fiberglass services but I believe I get a better price because I have a business account open already with them. if you own a business it may be worth it to open an account with them.


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## DuckNut (Apr 3, 2009)

mattyireland said:


> I though would tag on here as I have a similar query. Putting a front casting deck in my project boat and I want the area underneath as open as possible.
> 
> The casting deck will be 1150mm (46") from front to back, and the widest point at the rear of the deck is 1500mm (60"). Obviously, this will need some support underneath but I want it as open as possible. I was thinking Layup on the deck will be two layers of 16oz biaxial on each side of 1/2" nidacore. Want some advice on how much support under the deck would be required or whether I should increase the layup on the nida?
> 
> I was thinking of doing a couple of 3 nidacore "beams" across the width of the boat but only say 3 inch wide rather than all the way to the floor like a bulkhead. Thoughts?


Matty...you should delete your post and start a new thread as you are hijacking this dudes thread.


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