Reparing soft deck

[Rickysa]

I have to do this to same repair to the same boat:

https://youtu.be/6HR37V0Q7BA?list=PL0p_ ... XYo269sYG0

Is this the best way to do it? Seems fine, (tho' he does state he learned it all off youtube), but I was curious as to the use of 3/4 ply vs something else?? I'll be applying the same/some method to the '31 once I start.

[Ironworker]

I would absolutely use 3/4" coosa bw26 for your floor repair. You'll on have to do it once. It is also lighter.

[Ironworker]

I watched the video. I would do it a little differently with hopefully a lot less work.
I would cut out the rotted material from the bottom much as on the video being careful not to damage the top side of the deck. I would clean the best I could with denatured alcohol.

Instead of poly resin, I would use epoxy. I'd make a putty and spread with a trowel on the underside of the deck. In the video he used a layer of glass. You could add a layer of glass but I'd probably do that to the coosa before I mated it to the underside of the top deck surface, but use 1708. Wet the coosa side towards the top deck and weight it down as in the video and putty in the voids. Let it set up over night. BTW, this needs to be done on a level surface.

Grind off the rough spots on the putty, wet down the coosa and apply two layers of 1708. Grind off the rough stuff. Here is the word of caution. Try not to get resin runnoff between the topside of the floor and the surface you're working on. If you can do that you won't have to resurface the topside which is a lot of work.

BTW, I also have a Grady White CC that I need to replace the floor in. There is a lot of rotted wood in boat and I haven't started the project.

[Rickysa]

Thanks Rick,

I thought coosa would be the way to go, but I've only ever done fg/wood in the past. It'll be good to get some experience with it before I jump into the Bertram deck support rebuild.

[Ironworker]

drill some random holes in the coosa board to allow the resin below to be forced up through the coosa. That will help drippage on the finished surface.

Regarding you floor supports. I laminated 3 or 4 layers of 3/4" coosa with 1708 between. You can build your supports direct into the beam then shape them later for final fit. Vertically coosa does not hold screws well however, I came across a product that you can apply on top of the coosa beam. Once if fills with resin and hardens it will hold a screw better than pretty much anything. Apparently sail boaters are using it.

Unfortunately, I cannot remember the project name. Its a blue felt like product which is about 4" wide and comes in 50' roll or so. It was about $40. I am going to add some to my boat when I pull the floors next. I have the name in my records at but it will be a couple of weeks before I get my hands on it.

[Rickysa]

I think I saved a thread (I think it was yours (?) ) where one of our members posted a bunch of pics of their cockpit rebuild, as well as, explained the materials used (coosa/fg sandwich). I'm just not sure what computer it's on. I'll be starting next month.

[Ironworker]

I think I saved a thread (I think it was yours (?) ) where one of our members posted a bunch of pics of their cockpit rebuild, as well as, explained the materials used (coosa/fg sandwich). I'm just not sure what computer it's on. I'll be starting next month.

I have a bunch of photos that I can send you if you need some. Some stuff I would do a little differently these days. Coosa is a pretty strong product especially with some glass on both sides. I overbuilt my components.

[Carl]

I did several hatches and a section of my new to me deck similar to videos, has to be 15 years ago and they have held up great. If I was to do over again today I might go coosa so no worries if water got in through hatch pulls screws or…. Doing large sections lighter would be nice too.

What I learned the hard way is avoid heavy pours and to clamp or weigh down panels as when glass cures it can shrink a bit pulling and twisting panels.

[Yannis]

How about simplifying the whole project as follows:

Use the ply or coosa of your choice (Id use ply, bc coosa is unknown as a material here).

Clean the deck underside as shown in the video with the scraper and pass the alcohol for a full clean.

Apply sicaflex on the ply, around the edges and in a random pattern on the surface and stick it on the deck underside.

Paint a layer or two of polyester resin, no glassing, for eternal durability.

Much simpler and durable as hell, in fact one will have a hard time to separate the deck from the ply in 30 years to renew again…

[Carl]

Yannis, Coosa is high density polyurethane foam with fiberglass stands running through it. That makes is light, strong and won't rot or hold water making it great for structure and coring. Down side it not cheap and tools...they need to be sharp and of better quality to stay sharp opposed to working in wood. I think Duflex makes similar material on your side of the world.

Whatever the case plywood was the go to, sealed marine grade is a step up if you don't want to seal regular ply.

Now as far as adhering with sikaflex...I'd question its use. That said if you have stood on it, I am probably wrong. A big part of bedding ply or anything in resin is not to allow water in as the full surface gets sealed.A random squirt across leaves open space for water to penetrate. Ok, a layer or two of resin is fine to seal...but resin by itself lacks. My understanding, we have fiberglass boats not resin boats as the resin is the binder and the fiberglass is the structure. I guess same reason if you want to go up a notch to carbon fiber...its that base material that gives the properties looked for...light, strong, durable.

The reason for adding a backing layer aside from sealing is to add a tension layer to counter the top compression layer. My understanding is that having the compression layer and tension layer separated gives the panel, hatch, deck rigidity...more so then a solid panel that would flex in unison. Adhering ply to the top all that stress is right at the joint.

Hey Yannis...in the end I guess you went that way and it works. So as they say, more then one way to skin a cat. I'm not particularly fond of cats, but that's another story.

[Ironworker]

BTW, The product that I was talking about that holds screws is Trevira. This is a company that sells a lot of stuff but the product is a blue felt like product in a roll about 4" wide. You can use this product anywhere in a laminate or coring that needs to hold screws. Once the resin drys its hard as heck and you may need to drill a small pilot hole for a soft stainless screw.

I've been using this product for about a month now and really impressed with the product. You can use it with epoxy or poly resins. My fiberglass shop (Fiberglass Florida) has the product and does mail order. It's relatively inexpensive at about $40 a roll.

[franzmerenda]

...I think Duflex makes similar material on your side of the world.
/quote]

Carl,
Hopefully Coosa has an official Distributor based in Wesel - Germany and they are kind, responsive and affordable (accordingly to Coosa price lists).
Now that are several months that we're dealing with such a kind of material, I guess the downside is that Employees who are not familiar with cutting panels in a tailor manner make a lot of scraps and this means money wasting. Once you learn cutting panels into some puzzle shape, problem is solved

[franzmerenda]

... I think Duflex makes similar material on your side of the world.

Carl,
Hopefully Coosa has an official Distributor based in Wesel - Germany and they are kind, responsive and affordable (accordingly to Coosa price lists).
Now that are several months that we're dealing with such a kind of material, I guess the downside is that Employees who are not familiar with cutting panels in a tailor manner make a lot of scraps and this means money wasting. Once you learn cutting panels into some puzzle shape, problem is solved

[Yannis]

Francesco,

With all your dogs, it’s understandable you don't like cats LOL!! They probably don't like them either!

As for coosa, I have nothing against it as neither me nor anybody who I know has ever heard of this name.
Perhaps it sells under a different brand name but irrespective of all this, plain marine ply bonded with sicaflex and covered with a couple of layers of resin is there to stay forever.
If there is a gap between the new sole sandwich (deck/sikafex/ply or coosa or whatever/resin layers) then you measure and cut and bond underneath the appropriate number of slats that will hamper any walk-on vertical slack.
If you make sure that sikaflex is bonding all edges correctly and the resin gets well impregnated on the ply sides, then it will be generations before you need to do any additional mending, something like the pyramids of some sort.