Bow reinforcement

[wpstarling]

I ended up keeping my cv16 and I want to reinforce the bow so if I walk on it, it won't crack. I've been trying to brainstorm the best ways and I tried searching but didn't see anything. Any ideas or posts I'm missing?

Thanks,
Bill

[carlsoncvx18]

Take out the foam and put a core under the bow.

[wpstarling]

By core do you just mean a thin sheet of plywood? Or do I need stringers or something?

[carlsoncvx18]

There are sheets of end grain balsa ,  they are put down with resin then fiber glassed.   There are probably other products you can use.  A lot of boats use this on the bottom of there hulls to strengthen them up.  The core material can be found at Express composite.

[wpstarling]

There are sheets of end grain balsa ,  they are put down with resin then fiber glassed.   There are probably other products you can use.  A lot of boats use this on the bottom of there hulls to strengthen them up.  The core material can be found at Express composite.

Just looked that up and I can see how it would work.  I have some sheets of foam core and okoume marine plywood but I don't know if they'd bend enough.  Any ideas or recommendations on how to do this since I'll be working upside down?  How do you keep pressure on the wood/foam while the resin dries?

[Hyperacme]

Not sure what a late model CV16 without the bow fuel tank looks like .. But ..

Below is a 1974 thru 1976 CV16 and CV16SS.
You could remove the foam blocks if your has them and tab in wood cross braces, like wood brace behind dash.
Then tab / link to braces from floor to deck.

Take some pictures of your deck bottom please ..
Also wondering why you want to walk on your deck ?

Picture #1 is bottom of my deck, wood board is where the two braces attach to deck.
You can see wood brace behind dash. Maybe run one or two across bottom of your deck.
Picture #2  #3  &  #4 are braces from floor to deck.
Last three pictures are a 1974 CV16SS with console.

[wpstarling]

The bottom of my deck looks like picture 1.  My tank is in the bow as well but i have it sitting lower than what it's your pictures.  I was thinking of doing cross bracing but it seems like it would be hard to get each piece to curve with the deck but maybe you guys have suggestions. 

I don't necessarily WANT to walk on it but I want it to be able to handle it.  Most of the places I put in don't have a dock (or if they do they much higher than the water so it's useless to use to get into boat so I end up either climbing over the back or the bow depending on if there's room to turn boat around.  When I climb over the deck i try to stay near the side and it cracks a lot sounding like it's going to break and I'd like to make it stronger.  I know it's adding weight to the front of the boat but I'm not looking to make a 300lb person stand on it, just a 150lb one for a bit

[Plugcheck]

The good news is you're not planning to put a bass fishing seat and trolling motor on the deck!   I needed up the deck on my intimidator, but did so while it was upside down.   Is it possible to add some verticals between the floor/top?    The front tank structure supports the bow top on the Timi.   

[Hyperacme]

CV16 open bow ...           

[wpstarling]

Yea, definitely don't want to do the open bow 

I'll get some pictures.  I did some vertical bracing but it was rushed because I had to move and it was half done when I found out we had a few weeks to find a place and move so it's not very good.  I am thinking of just cutting out old foam, putting a layer of foam/plywood against it and then adding a few vertical support pieces on it.  Just want to do it right this time since I have a few months to do it and I have most materials, just need a little epoxy.

[thedeuceman]

Both Shawn and I are redoing CV16V8's. the layup on the bow is really thin, and the foam logs do flex and make noise (our GT150 did as well).
I also go over the bow a lot.
we are both removing foam logs and replacing with core material.
Shawn has his split, I believe he is using end grain balsa (same as he did on his CV23) i think all ya have to do with that is wet out CSM and lay the balsa on, then more CSM on top of the balsa.
the balsa is in small squares with a scrim attached so it will easily contour to the shape of the bow.
On the one I am doing (not splitting the hull) I will use 3/4" plasti core and will set it by screwing fixture boards together through the plasti core and the bow.
I will be redoing the gel/flake so the holes will be easily fixed.
We will be adding supports as well, the location will be determined by the final location of the fuel tank.

[wpstarling]

Yea I already painted it so can't screw threw it but I think I can do something similar, just have to see how I can 'glue' the bow and the foam/wood together while upside down since gravity is against me.  I will tackle the first task of removing the foam blocks after Christmas.

[Hyperacme]

The foam was for floatation .. but shouldn't it act like a "core" and just need support from bottom to floor ?
Just thinking out loud .. 

[wpstarling]

The foam was for floatation .. but shouldn't it act like a "core" and just need support from bottom to floor ?
Just thinking out loud ..

It can but it is a bit 'squishy' so it isn't as solid as reinforcing it i think.  I filled the floor with foam when I re-did it so I don't think removing it will be an issue.  I'm thinking once I remove it I can better gauge how to reinforce it.  Since it's contoured I'm thinking of using the foam I have since it bends easier and I can epoxy it to the underside of the bow and then just put in a few vertical reinforcements and voila.  At least that's how it is in my head, i'm sure execution will be different 

[Hyperacme]

"  At least that's how it is in my head, i'm sure execution will be different  "

Ain't that the truth !   

[carlsoncvx18]

Have not done it but maybe a person could use a vacuum bag process to bond it to the bow.

[fireman24mn]

If you are not gong to split the hull you will more than likely have to vacuum bag the areas to get everything to bond.

[wpstarling]

Alright, i flipped the boat.  It's now upside down (in one piece mind you).  I also removed the original foam flotation and grinded it as flat as I possibly can, which honestly isn't THAT flat.  I want to now take the foam core I have and epoxy it to the under side of the bow.  Basically I'm thinking to cut the foam to the shape I want, put down some thickened epoxy on the bow, put the foam core on it with some weights to make the core 'bend' to the contour of the bow and then once it's dried I will put some fiberglass over that to reinforce it. 

Questions are:
1) When I put down epoxy on the bow do I also need to put some on the foam core?  That way both surfaces have epoxy or is that overkill?
2) Since the bow area that I removed the flotation foam from isn't 100% flat do I need to use extra epoxy or just concentrate on the 'high' areas where the foam will contact the bow?

If the above is confusing let me know and I'll try to snap a picture of what I mean.

Thanks,
Bill

[Plugcheck]

You will want enough epoxy to fill in the gaps between the core and the original surface.   Any gaps would become a weak spot, possibly flex, and crack the finish.    I would recommend going over the original surface with a sander to knock down imperfections and provide a better bite for the epoxy.  Putting epoxy on both sides would insure enough to fill the gaps, I'd recommend at least one helper to set the core in place.   Good luck, and we love pictures!

[Hyperacme]

Could you use some that is " Micro scored" to conform to curves of deck ?

https://www.expresscomposites.com/products/core-materials