Sticky Deck Question

Neicy · #1 (**permalink**) 10-11-2007

I have discovered that an area of deck to the right of my front hatch on the starboard side moves slightly when stepped on. When pushed down you can hear the sticky sound. The area is about a ft square.
In checking this out I have found a similar area inside the cabin. This area is the main cabin, just aft of the wall that separates the head from the salon. This also is on the starboard side. The headliner is fiberglassed.
This area has a larger void area but also is very tacky when pushed up against the core. My question is can this just turn loose over time or do I have a wet core problem. Sounding with a hammer it does not sound wet but I am not that knowledgable in this area. What would be the repair method if this needs correcting. The boat is a 77 Dufour 31.

NOLAsailing · #2 (**permalink**) 10-11-2007

It is possible that the outer skin delaminated and the core is still intact, but that is unlikely. The easiest way of checking the core is to drill a test hole. You can go from the top or bottom, but only go through one of the skins into the core. If it is wet, you'll know. Good core is bright and dry.

There have been a number of recent threads on core repair, I suggest searching for those and, if you still have questions, updating this thread.

Neicy · #3 (**permalink**) 10-11-2007

How large of a hole should I drill to be able to see the core? From the inside this would be the V berth but it is not tacky from the inside in this area, but I supposse if it is wet you would know from either side. I also thought about removing the front hatch to see if anything is visible from there.

camaraderie · #4 (**permalink**) 10-11-2007

Neicy...I would go in from the top side with a 1/4" drill bit...the drill bit will pull our core material as you drill. Dry=good...wet and rotted =bad.
I would start my first hole on the "uphill" part of the area in question. If you find rot...you can work your way downhill with additional holes to see how extensive the area is. If it is only a few inches...you can try injecting epoxy with a syringe. If it is more expansive...it will be more expensive.

Freesail99 · #5 (**permalink**) 10-11-2007

If you drill the 1/4 hole you can use a Alan key ( spelling ? ) in a drill on a very slow speed to widen up the inside of the hole without making the 1/4 hole any larger. The short end of the Alan key would be going into the hole. By doing this, you increase the volume of the inside of the hole, allowing more epoxy to be added to the hole and increasing it's strength.

Neicy · #6 (**permalink**) 10-11-2007

I am assuming by the answers that I should only concern myself with the sticky area on top deck and not worry with the other area that is in the cabin. The interior area has a much longer push before the sticky, and it also is in a totally different area of the boat.
I also want to make sure it is better to puncture the exterior instead of the interior at the V berth. It seems this is what you are suggesting. I do hate to go drilling holes in the deck but if that is the best way to proceed I will give it a try. I did contact West Systems about the epoxy and the guy on the phone suggested removing the hatch and taking a look from there. However removing a hatch is no small feat its self. Thanks for the suggestions to deal with this matter.

camaraderie · #7 (**permalink**) 10-11-2007

Actually..a leaky hatch may be at the root of any delamination/core rot...so if you find rot in your first test hole near the hatch...you should probably remove and rebed the hatch or the problem will return. It also may be easier to dig the rot out from the hatch side.

You should not be concerned about interior fiberglass unless the exterior in the same place is soft as well. Best approach is from the outside in your case I think.

sailingdog · #8 (**permalink**) 10-11-2007

I don't recommend this technique for anything larger than about a square foot in size. The epoxy is heavier and doesn't add as much strength as properly rebuilding the laminate by re-coring it would. IMHO, if the core is rotted to any degree, you're much better off re-coring the deck in that area—rather than doing a bubble-gum and baling wire repair.

Quote:

Originally Posted by Freesail99

If you drill the 1/4 hole you can use a Alan key ( spelling ? ) in a drill on a very slow speed to widen up the inside of the hole without making the 1/4 hole any larger. The short end of the Alan key would be going into the hole. By doing this, you increase the volume of the inside of the hole, allowing more epoxy to be added to the hole and increasing it's strength.

Freesail99 · #9 (**permalink**) 10-11-2007

Quote:

Originally Posted by sailingdog

I don't recommend this technique for anything larger than about a square foot in size. The epoxy is heavier and doesn't add as much strength as properly rebuilding the laminate by re-coring it would. IMHO, if the core is rotted to any degree, you're much better off re-coring the deck in that area—rather than doing a bubble-gum and baling wire repair.

If you re-read his post, the area is 1 foot sq.

sailingdog · #10 (**permalink**) 10-11-2007

FS-

He's actually talkng about two different areas. One area is estimated to be about a square foot in size, but he hasn't drilled into the laminate to figure out its exact size yet.

The second area is larger than the first, and therefore is larger than a square foot and will probably be better treated differently.

Quote:

Originally Posted by Freesail99

If you re-read his post, the area is 1 foot sq.