Soft Area on Deck

[denpooch]

Hey Folks,
I require your help and advise with a project.
As I am now using the boat I have found a soft area on the centerline engine room hatch. This was not evident in the fall. The soft area runs from the engine room lock to the about halfway to stern door.
My first thought was de-lamination. I was thinking that over the freeze and thaw of winter the core detached from the glass.
When I took a good look at the underside I noticed that the lock was rusty. Now I am thinking water intrusion.
Does anyone know of a fix that I can do myself instead of getting a glass guy ($!) for the job.
Since I have access to the underside, I can make holes, etc., without affecting the cosmetics topside.
I remember seeing a product on a TV show which after drilling a couple of holes, was 'pumped' in on one side and
came out of the side. It cures hard.
Does anyone have thoughts, experience or recommendations to help me out?
Thanks

[km1125]

If it was me, I'd wait till fall and make it a winter project.

If it can't wait, I'd make a plywood replacement (probably just a couple 3/4" or 1/2" pieces glued together), paint it white and put it in place of the existing hatch so you can continue to use the boat. Then I'd take the hatch home, use a heat gun on the insulation and remove it carefully from the underside. Then I'd tap all over on top and bottom to isolate the bad section. Then cut out the underside of the hatch where the bad section is, and keep expanding that hole until I got to solid core material. Dry it out real good and replace the solid core, then fiberglass over it. Clean up the edges, repaint (or gelcoat over) and re-apply the insulation using some good 3M adhesive. Then make sure that latch is sealed properly when remounted. Then put it back on the boat.

I wouldn't use the Git-rot or equivalent. You need to dry out the core and all it will do is make the core hard but not re-laminate it to the top of underside for full strength.

[bud37]

I agree, really quite easy fix like KM said just cut the bottom open and peel surface off, recore then glass the piece you peeled off back on.....all from the backside.....see if you can borrow a moisture meter, that will map it out pretty good......do it all in the garage at home.

[tomschauer]

The only thing I would add to the above is if it feels very spongy and flexible underfoot, replacing just the wet and or rotten part of the plywood wont resolve the flex as the plywood has lost its structural integrity. You can still execute the repair from the rear as mentioned above, you just need to cut and replace the entire piece of plywood, adhere it to the top side and reglass the bottom side.

[Viper]

I agree with all the above. You could simply use it as it this year providing you determine what's going on. If you say it's just a delamination and the core is still somewhat structurally sound, then use it for the season. Looks like the core is wet but a sounding on the underside will tell you how punky it is and whether it's safe to use until winter. If it's punky, you'll know it, it'll be spongy and really dull sounding when you hit it with a mallet. A sounding on the top of a delaminated piece will sound sharp if the core is still okay but you can tell that there is a gap between the surface and core.

When you cut into it, start at the sections that have hardware fastened to it; hinges, lock, carpet domes, etc. as those are the likely sources of water intrusion. Personally I would open up the entire piece. Chances are they used balsa core to keep the weight down.

[denpooch]

Thanks to all. I appreciate your insights and will keep you posted on progress.
I am thinking that if its gonna be a fall project my thought is to place a piece of 1/2" plywood (glue some felt on bottom so I don't scratch the gel coat) and cut the wood to cover the soft part of the hatch with an extra inch over hanging either side of the hatch door. Perhaps stepping on the 1/2" will eliminate pressure on the spongy deck. I would then cover the plywood with indoor/outdoor carpet for aesthetics.. Although KM's idea with replacing the entire hatch with a plywood door until it is fixed is better; cosmetically speaking the admiral would have me 'walk the plank'!
Do you folks think that idea can work to get me through the season? All alternate ideas to get me through the season are enthusiastically welcomed!
I don't feel comfortable walking on it in the current condition. I don't want to wind up with stress cracks on the surface.