Time to dive back in - transom and deck replacement

bakerjw

Petty Officer 1st Class
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Apr 3, 2013
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292
Close to 11 years ago, I did a down to the hull rebuild on my 1850 Stratos CC.
I love the boat! Been offshore a handful of times out of Sneads Ferry N.C. I have learned what wave conditions I can handle in her and it is glorious! 4' to 5' is possible but leaves no margin for error. Those days, we go fish inside of the inlet.

In a past post, I found where I had water had gotten in to the transom. And then a soft spot developed on the rear deck near an access hole that had not been properly sealed. It is what it is. I know what to do.

Scott answered my question on composites

Fixing the soft floor will be tough without pulling the cap as it is strongly secured to the entire deck which is secured to the sides so I'm going to replace the entire deck.

When I originally did the rebuild, I was not in the same financial position that I am now. Going with lighter materials is a key focus now.
 
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bakerjw

Petty Officer 1st Class
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Apr 3, 2013
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The deck.
For the deck, I am planning on using 5/8" Nida Core laminated between layers of 1708 Biax with an added layer on top to get close to the 3/4" of the original decking. The stringer and bulkheads are close enough together where there will be sufficient rigidty.

I am also removing the livewell as we never use it. That simplifies the underdeck plumbing tremendously. Bilge pumps and washdown are all that is left. The area that spans the center where the livewell is currently at will be reinforced with additional strips.
 

bakerjw

Petty Officer 1st Class
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Apr 3, 2013
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292
The transom.
This is where decisions will need to be made.
Let me be clear because someone will say it. I am NOT using wood again. Ever. The Stratos 1850 CCs have always sat low in the back. When I went from an older 150 OB to the 175, it got even worse.

A color code.
  • Brown is the hull and deck. Approximately 1/4" fiberglass
  • Red is an epoxy mix with cabosil and cut glass.
  • Blue is whatever material that I end up using
  • Green is 1708. The transom will be tabbed to the bottom and sides of the hull as well at the stringers.
  • Purple is a crush preventer of epoxy, cabosil and cut glass for the outboard mount.
  • Black is where the hole will be drilled for the outboard.
1 layer of 1.5" Coosa Bluewater 20 - Preferred option.
1764941844306.png

2 layers of .75" Coosa Bluewater 20
1764942148061.png

And an outside of the box option.
2 3/4" Nida Core panels. It offers very lightweight structural support but has less crush resistance. Using crush zones like the purple are necessary. This can save some weight and will likely work well but there will be additional work involved. It was just an analysis.
1764942247619.png
 

eggs712

Petty Officer 1st Class
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May 8, 2012
Messages
361
I would look up the technical data sheets for the honeycomb panels versus other materials. Honeycomb panels tend to be good in compression, but poor in other specs. It may still work, but could require other alterations to achieve the same strength as original.
 

bakerjw

Petty Officer 1st Class
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Apr 3, 2013
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292
If I had a boat with easier access to the transom, I'd probably try it as an experiment.
I'm likely going with dual layers of bluewater 20 laid in place with 1708 biax.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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both coosa and nida are core materials. they are there to add spacing between layers of fiberglass. they add an ever-so-slighly advantage over foam

they are not structural like wood is

they require fiberlass laminated to them to make a composite sandwich.

make sure your laminate schedule is correct for the loads applied
 
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