Carbon to reinforce Deck

[RELENTLESS 1]

We are experiencing deck flex around the forward bow hatches on our friends Outremer 4X which then leaks washing boat or when we get green water (very rare) over the deck. It is not a 'critical' area and clearly the factory in going light on this racing version built this 'good enough'. However when you stand on it you can flex it a cm or so which means the hatch leaks.

My thought is to buy some Carbon Fiber 90" angle pieces and then either epoxy or use some 5200 underneath the deck at the back and front of the hatch in an attempt to brace the deck against flexing and keep the hatches from leaking.

Any thoughts? It's not cheap but I can buy 90" lengths of 1.5" x 1.5" for $180. I wish I were the craftsman type that could make my own - but the few attempts at hull nick repair on my J80 have convinced me that is not in my gene pool!
Thanks

[jimbunyard]

Looked at a sails video, have no experience with the 4X. By 'forward hatches' do you mean the farthest forward sail locker hatches?

If so, and the deck is not cored, then adding a layer of carbon underneath will have little effect. Most likely the only way to add stiffness will be to add 1/2 coring underneath, and then laminate your carbon fiber over that, which will add significant stiffness.

Won't be the easiest job in that confined space, but it is doable.

[Chotu]

I’m thinking this will have a good effect.

You are talking about carbon “angle iron “ premade at a pultrusion shop?

Those will definitely stiffen it up when added below deck.

[jimbunyard]

Oops, misread, angle 'iron' strategically placed will work, as long as they stay attached.

For uniform stiffness over the whole area, coring, if not already present, is the way to go.

[Chotu]

Originally Posted by RELENTLESS 1

We are experiencing deck flex around the forward bow hatches on our friends Outremer 4X which then leaks washing boat or when we get green water (very rare) over the deck. It is not a 'critical' area and clearly the factory in going light on this racing version built this 'good enough'. However when you stand on it you can flex it a cm or so which means the hatch leaks.

My thought is to buy some Carbon Fiber 90" angle pieces and then either epoxy or use some 5200 underneath the deck at the back and front of the hatch in an attempt to brace the deck against flexing and keep the hatches from leaking.

Any thoughts? It's not cheap but I can buy 90" lengths of 1.5" x 1.5" for $180. I wish I were the craftsman type that could make my own - but the few attempts at hull nick repair on my J80 have convinced me that is not in my gene pool!
Thanks

Add on: what’s your source for these? I have a huge order of them I’m working on myself and all the pultrusion shops are really slow responding.

[RELENTLESS 1]

Thanks for the quick reply all - I thought that would work and wanted some input just in case I wasn't see it right.

What would you suggest to fasten it - I am leaning towards 5200 as that would be a fair amount of epox, or should I find some epoxy resin to use?

[Chotu]

Originally Posted by RELENTLESS 1

Thanks for the quick reply all - I thought that would work and wanted some input just in case I wasn't see it right.

What would you suggest to fasten it - I am leaning towards 5200 as that would be a fair amount of epox, or should I find some epoxy resin to use?

I’ll tell you if you tell me where to get these pultrusions.

I’d use epoxy for the “set it and forget it” peace of mind. It also takes 5200 forever to cure. It’ll be done that day with epoxy.

[jimbunyard]

Epoxy plus thickener, probably fumed silica would be best, but milled fibers or even glass bubbles would work. Don't forget to roughen the joining surfaces with 80 grit or so before gluing and dewaxing/degreasing before that...

[Bill Seal]

If you just glue it to the overhead, you'll end up with all the structural integrity of Polina Star III. Think of how deck beams are supported, or window and door headers in buildings.

[NevilleCat]

Jeez, I'm glad it wasn't me paying $xM for that boat. Inconceivable for the sake of a few bucks worth of core stiffening!

[ggray]

Pictures of the area you want to reinforce would help, but I would think you could get a superior job by using cloth, be it 'glass, CF, or Kevlar, and epoxy resin. Possibly core material as mentioned
Gluing structural members with---even epoxy rather than 4200--- seems crude for any decent boat.

[RELENTLESS 1]

Chotu,

I just started searching - and in no worry - this was easy to find but havent checked availability:
https://dragonplate.com/carbon-fiber-angle
https://www.rockwestcomposites.com/s...n-fiber-angles

As for the full header and king stud - a bit of overkill but I think a support glassed in at the ends make sense.

I will roughen it up for sure - and the silica I haven't heard of but will do my research.

As for $xM - it is a calculation - the joke (sic) concerning weight on our boats is: you have to cut your toothbrush in half to board.

[jimbunyard]

Cabosil = fumed colloidal silica. Cheaper by not paying for the brand name.

[Chotu]

Originally Posted by RELENTLESS 1

Chotu,

I just started searching - and in no worry - this was easy to find but havent checked availability:
https://dragonplate.com/carbon-fiber-angle
https://www.rockwestcomposites.com/s...n-fiber-angles

As for the full header and king stud - a bit of overkill but I think a support glassed in at the ends make sense.

I will roughen it up for sure - and the silica I haven't heard of but will do my research.

As for $xM - it is a calculation - the joke (sic) concerning weight on our boats is: you have to cut your toothbrush in half to board.

Ah... I know these places. Thanks for confirming.

You’re on the right track with the epoxy thickened with silica. You just mix it into your epoxy and make it “not drippy” so you can put the epoxy on like spreading mayonnaise or some thin peanut butter.

I’ll add also to some posters that he’s not doing any vital structural work here. He’s stiffening up part of the deck near a hatch to prevent flexing. He doesn’t want to do an upside down, messy, awful laminating job in a new boat. He wants to simply bond a structural beam on to make it so it doesn’t flex when he’s walking on it. No need to engineer it like it’s a structural repair. Hell, he could cut a couple 2x4s the right length and tap vertically them into place to solve the problem. Ha ha. It’s just not that critical.

Relentless: is there a camber to the deck? There usually is. If there is a curve like that, you’ll need to account for it by putting something between the absolute straight carbon “angle iron” and the curved deck shape.

[Benz]

Originally Posted by RELENTLESS 1

Chotu,

I just started searching - and in no worry - this was easy to find but havent checked availability:
https://dragonplate.com/carbon-fiber-angle
https://www.rockwestcomposites.com/s...n-fiber-angles

As for the full header and king stud - a bit of overkill but I think a support glassed in at the ends make sense.

I will roughen it up for sure - and the silica I haven't heard of but will do my research.

As for $xM - it is a calculation - the joke (sic) concerning weight on our boats is: you have to cut your toothbrush in half to board.

Forget silica: look into buying tubes of Pro-set. It's a pre-thickened epoxy paste in tubes with self-mixing nozzles. Using it will give you a stronger and more consistent product without the bother of mixing silica. I've built racing boats that had ring frames (essentially hollow bulkheads meant only for reinforcing) that were attached to the hull by nothing but Pro set. Ditto an entire keel grid. It's worth the price.