Crownline 250CR cockpit floor repair

Joined
Jan 8, 2013
Messages
29
I'm looking for some insight as to the most effective way to repair the cockpit floor. It is soft and springy over the left half where the walkway is and I surmise that the core is wet. It seems that the most likely point of water entry was the bolts which secure the captain's seat. This is the floor which separates the cockpit from the mid cabin and so is accessible form both top and bottom.

Pictures for reference are in cockpitFloor - a set on Flickr

I did some disassembly of the headliner to survey how it is constructed. The rear few inches is solid glass and then the core is laminated in. The front appears to lap over a bulkhead and is then tabbed to it on either side of the entrance to the cabin. The sides are glasssed over into the cockpit tub wall. You can see from the video where the port side is soft (i easily push it with my foot) and the starboard side is still solid. However the whole under the seat area isn't good so probably 80% needs to be redone.

Looking at all this, my plan of attack is to attempt to repair from below, since it will not be visible. I would cut away the bottom skin, remove any bad core and replace it and then re-skin and tab with glass/epoxy.

Several questions:

1. Should I try to remove the entire bottom skin and redo it or only the bad portions and then have a lap joint where I join the new to the old skin?

2. What tools will help me to best remove the skin and core materials, keeping in mind that i'll be upside down.

3. If I remove the whole way to the forward bulkhead, there's nothing to tab to over the entry door. Maybe I can tab it up around the front similar to how the sides are done in this area?

4. I'll use 1708 biax for the tabs, but if I have to skin a large area of the bottom would woven roving be better? This is what it looks like the original material is. How many layers will I need to make a strong repair?

5. If I do end up cutting the majority of the core out, would it make sense to take it all out and replace it with solid fiberglass sheet for a core instead of wood?

6. Does this plan make sense or would attempting the repair from the topside be better?

Thanks for the help - this will be my first major glass repair but I do have a couple of books on it and feel like I can handle it with some help from the board.
 
Joined
Jan 8, 2013
Messages
29
Re: Crownline 250CR cockpit floor repair

Alright well getting ready to get this done and need to order some material.

The unsupported overhead area is 66" x 45".

I'm going to cut off the whole skin, then replace any/all plywood that is bad and re-skin. Then I'll tab it all around into the original structure.

I would like to use a minimum of 1 layer each of 1708 and 1808 biax for the main lamination. Is 2 layers enough strength/stiffness or should I use 3 or 4? I'm also open to the 1700 (no mat layer). The original material appears to be a single layer of 24oz roving. I want this to be rock-like in solidity but there's no sense wasting money and time.

I'll likely do the tabbing with 2 layers of 1700 unless someone has a compelling reason to include mat in the tabbing.

Looking at US composites 3:1 epoxy. Anyone who's worked with this: is it going to be slow enough in 80+degrees or should i go with the 2:1?

Any help is appreciated. Will post pics once demo begins.
 

mcmarcia

Seaman Apprentice
Joined
Oct 24, 2011
Messages
39
Re: Crownline 250CR cockpit floor repair

I am also wondering about the 3:1 or th the 2:1 epoxy for above 80 degree temps. How is this coming along? Which epoxy did you go with and how much working time for the mix?
 
Joined
Jan 8, 2013
Messages
29
Re: Crownline 250CR cockpit floor repair

Sorry been a whirlwind season and I didn't get back around to posting.

I used the 3:1. It worked well even in some hot weather. You couldn't waste any time mixing in your fillers but I was able to mix batches of about half a solo cup at a time. Once it was spread it was fine to work with. I also found that if you rolled out some epoxy overhead and let it set up for about 10min that the biax cloth would stick nicely to it. Then I would just keep using a paint roller and work more epoxy into it until it was wet out, and use the metal roller to work it.
 
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