'Bouncy' Cockpit Floor

[Nickelrw87]

Hi everyone!

I noticed that my cockpit floor is 'bouncy'. There seems to be some give when stepping onto it. That is the only soft spot i can personally feel. The attached picture isnt mine, but just to show where im talking about (as if the cockpit floor description doesnt explain it well haha). If i look under the cockpit floor, when im in the cabin, i can see a VERY VERY thin peice of plywood, but it sure as hell doesnt look like it would hold any sort of weight.

Boat is a 1974 Catalina 27. What can i do to fix that? I was seeing the 'drill and fill' but i am not sure if that would apply to this issue.

[JPA Cate]

There's probably a Catalina 27 owners forum somewhere; suggest you look there.

However, you can stiffen plywood like that by epoxying athwartships 1" x 1" strips underneath it. Maybe three of them, equally spaced, would do it. On the underside.

Ann

PS. If you ask Uncivilized, he will tell you the engineer's way.

[UNCIVILIZED]

Quite a lot of cockpit sole are simply made of (relatively thin) solid fiberglass, & thus are pretty flexible (bouncy). And if the plywood on the cockpit's underside wasn't glassed over significantly, then it won't serve to form a stiff, cored structure such as you have in your decks.

You could:
- Add a thicker piece of ply, & count on it's stiffness to stiffen the cockpit floor.
- Add a core to the cockpit's underside, & add a significant fiberglass skin over it in order to make the cockpit sole into a stiff, cored laminate.
- Add stiffeners, or "ring frames", much as Ann suggested.
Ring frames typically being 3-6" widths of core material bonded to the skin of the structure in question. And they're then heavily glassed over. Thus forming low profile cored composite "frames", AKA "ring frames". Which they're used on all manner of higher end composite boats to save weight vs. standard frames. And to maximize space inside of the boat, without frames intruding into her interior.
- Then, of course, you could add some metal frame work

There's info on these topics on the www.WESTsystem.com site, in the User Guides, & the excellent book The Geugeon Brothers, On Boat Construction. As well, no doubt, as some videos online. Many of them findable via any large composites retailer or producer. https://www.systemthree.com/pages/literature , or www.ItchingForFun.com for example. And www.CompositesWorld.com is an excellent info source, plus there's www.CompositesOne.com or www.Gurit.com
And all of the above are gratis!

[Suijin]

I think you need to determine whether it's "performing as intended" or there is some structural degradation that needs to be addressed. A few pictures of the boat could certainly help.

If it's cored and rotted, which would not be unusual in a '74 boat, then you need to fix it to prevent further deterioration and damage. "Drill and fill" will probably not cut it, but again impossible to say without more information. If it's working as intended but you just don't like how bouncy it is, Anne's idea for reinforcement sounds like a great approach.

[Nickelrw87]

Thank you everyone for the advice. I think my next plan of action is just to see if its "working as intended" such as Suijin has said and then work back from whatever is found.