Deck Delamination / Core Problems

[Bill]

Good Old Boat has placed the Sandifer delamination repair artical on its Web site at read it online at:
http://www.boatus.com/goodoldboat/delalimation.htm

[Robin]

Bill,
thanks for posting that Good Old Boat article, I'm in the process of thinking out how to tackle my decks on the side of the cabin. I tried the method where you drill holes, but it looks like I didn't quite get all of it as I'm getting spongy areas again. So I'm considering cutting out a whole panel. What I'm concerned about is running into areas of rotten core alternating with good, still laminated core. Which makes it impossible to get a panel of fiberglass off cleanly. Any suggestions?
Robin

[Bill]

Sorry, but I have no idea. Two suggestions, however. First, ask a professional. Most yard people are very helpful. Second, wait and maybe someone will reply to your post.

[Dave]

Robin,
I have repaired soggy core on my Ariel, including removing six feet of the outer skin on the port side deck, replacing the core, and and reattaching the skin. Of course, it requires cosmetic glass work and repainting the whole deck including determining how you will restore the non-skid (I used glass beads).
I'm happy to tell you how I did it, and have a few pictures, if you're interested.
--Dave Gillespie

[Brent]

Dave,

Please--tell us about how you repaired the core on your Ariel and post the pictures. I'll be tackling this job in the Spring and could use the info.

Thanks in advance,

[tcoolidge]

Hi
I had to redo my port deck along the cabin too- leaks from the stanchion base and from the jib block tracl pretty much turned to core to mush. I cut away the delaminated deck and cleaned out the debris until I got to sound wood that was still adhered to the glass, then dried it out as best I could (not an easy undertaking in Seattle in winter) then cut endgrain fir blocks to fill the core, embedded them in epoxy and glassed over it all again then painted it.Turned out surprisingly well, considering. I also glassed in a much more substantial backing plate for the stanchion base so the load is much better supported. There are any number of sources for info on how to fiberglass and it's really pretty easy. It also has the benefit of being easily removed with just some grinding if you don't like the result and want to try again. It's been three years since I did mine and I haven't had any problems- no leaks, no flex, no cracks so I'm pretty happy.
Tom

[Theis]

I do have an idea for you that worked well for me

I had one deck area alongside the starboard windows that was a total disaster. The area was the width of the deck and about a foot to 18" long (although for this procedure the size shouldn't make much difference).

I used a Dremel tool with a small router type bit (1/8"as I recall). Marking with a pencil the path for the cutout, I cut out the section of the deck fiberglass over and beyond the area known to have the rotten balsa. I wanted to preserve that deck piece because it has the tread and it would be used again. The cut was at an angle to the extent possible so that the deck piece, when replaced, would not fall through the hole, i.e. cut so that the perimeter of the deck cutout with the tread pattern was larger than the underside.

Then, using varioius chisels and stuff, I cleaned out all the rotten balsa (I think). When the wood started coming out dry and relatively light colored, I assumed that was enough.

Then I filled in the void, but not quite to the deck underside level, with glass mat and resin which in addition to being a filler for the void, also sealed the remaining balsa at the edges. When that had cured, I placed the deck piece cut out over the hole. In places where the cured glass was above the bottom of the deck level, it had to be ground or sanded down with the Dremel tool grinder or 80 grit sandpaper so that the deck piece would fit level with the deck.

I then covered the deck area around the hole with stuff you can get from West that keeps glass from sticking, and did the same with the tread side deck cutout piece. The hole was then filled with resin and a layer of glass and the deck piece cutout placed over the cutout. Wax paper was then put over the entire repair area, which was then covered by a board with heavy weights to force the deckpiece cutout to be flush with the remainder of the deck (The wax paper prevented the board and the weights from sticking to the deck piece cutout and the deck).

When done and cured, the deck and the cutout were level, the deck non-skid pattern was undisturbed except for the 1/8" bead around the cutout. When repainted, the cutout does not even show. You really have to look very close to realize that there was extensive work done on the deck.

On another section (under the mast) I had tried drilling holes and inserting Git Rot. That had turned into a total, time consuming disaster. I think I did fill the void, but the deck and deck pattern were so botched up, that it is easy to tell that they are different

[Bob G]

I need to repair some rotten core on the foredeck portside (about 2.5 ft by on 1 foot) and side deck on the starboard side (almost the same size). Also some slight delamination on the starboard side deck. If I remove some skin, where does one get the balsa or is there better wood to use? Does it come in various thicknesses? Can you just use some type of epoxy filler. I have read the previous ideas and it helps. Thanks in advance. Bob

[ebb]

Baltec from www.defender.com
800/628-8225

[Janice Collins]

Why would anyone want to replace that balsa core that turns to
mush with more of the same????. Masochists at heart??? I need to do something to a spongy area on the foredeck too, in fact all Ariel owners seem to have to do the same,

What was the advantage if any, to the balsa core ? I see it as a big PIA!!!

[Dave]

I'm in the process of rebeding all the deck hardware on Brigid: drilling oversize holes, cutting out core material from the sides of the holes with a sharpened allen wrench on the drill, and refilling the holes and undercuts with thickened epoxy. When I redrill for the hardware, it will be through epoxy and any leaks shouldn't reach the core.
I'm going to all this trouble because I've removed too much balsa mush from several small and large deck and cabin top repairs. Previous owners just didn't maintain the hardware fittings.
I can understand balsa's appeal to the builders: cheap, light, oddly strong, and when grain is placed vertically, relatively resistant to water penetration. But over time, any delamination in the presence of leaks, and the stuff completely fails.
My larger repairs have been with marine plywood presealed with epoxy, the smaller repairs have been with thickened resin.
I'll avoid balsa altogether.
--Dave

[Bob G]

Was the space(thickness) of the deck filled with the balsa core fairly uniform, or did it require various thicknesses of whatever wood filler was used. I haven't skinned her yet, and am trying to do a liitle planning ahead. I agree, I am tending to steer away from balsa, and am looking at other wood and/or just glassing it or filling with some epoxy filler. Anybody see any problems with either method?

[Theis]

I would suggest using glass and resin after you have cut out as much of the bad stuff as you can reach through the deck cut. The glass resin penetrates and seals the core where you could not reach. With a resin paste, you may not get this sealing action and in fact may leave hollows. When I did mine, I used fiberglass mat, not the wovoen glass cloth, just to bulk up the gap (alongside the starboard aft window). Then I covered it with the piece I had cut out of the deck and leveled it so that, when cured, the deck would again appear intact. I am assuming that the resin will not run straight through into the cabin, in which case you need tape and a piece of plastic to block the leak.

[Dave]

Bob,
The balsa core is a consistent thickness throughout -- except at the edges, i.e. near the caprail. I agree with the use of unthickened epoxy as the first step; it tends to run into the spaces where the deck may have delaminated (delam can exist even if the core is dry -- these are production boats).
Epoxy thickened with filler is great for sealing off the repair and when smeared into an undercut in the seam you've cut, strengthens the joint. Coring material (marine plywood, airex, balsa) weighs less, is less expensive, and is easier to install than a glass mat build up in my strictly amateur opinion.
--Dave

[Mike Goodwin]

Here is what I did with #45 last year;

the core was completely gone from the cockpit forward on the starboard side and the entire foredeck , the balsa was like tuna in the can .
the foam is called wescore , it is a foam filled honey comb .
After putting new core in , the old deck skin went back on then a layer on fresh glass over the whole repair.