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post #22 of Old 03-23-2009 Thread Starter
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Delamination repair

So after discussion with many smart people, we're leaning on biting the bullet and starting on the major project - repairing the foredeck delamination - now instead of waiting until the fall as was the original plan. We figure this project may take about a month and a half from the first cut to the last coat of paint, so I would rather lose that cruising time now, rather than in August and September. Also, it leaves a bit more room for the unexpected time-sucking troubles that will surely arise. Plus some of the smaller projects are either moot once this is done, or can't even be started until we've completed this.

We've discovered that there's water leaking into the v-berth from the pulpit attachment points, which is where we figure all of the deck delamination issues originate from as well. My guess is that this has been happening for many, many years. At some point, somebody has tried to seal the pulpit with sikaflex or something similar to no avail. Water has seeped into the core almost to where the cabin top starts, about 5 ft. back from the bow. There's about 10 sq.ft. which will need to be removed. We've been told that considering the size of the damaged area, and how little structural stability remains, the core is probably rotten, not just wet. Simply drilling holes will not dry it out, so we'll be cutting out the inner layer of fibreglass, grinding out the wet core, relaying a new core, and re-glassing the whole thing. *sigh* All from the inside (for a plethora of reasons). Yes, we are insane.

It shouldn't be too terrible of a project... apart from that pesky bow locker, which is partially isolated from the v-berth by a bulkhead with a large access hole. The leaking water is running through this locker and under the v-berth to the bilge. (you can see where it runs out in the photo). Inside this locker is a bulkhead (I'm not sure what one would call this - bulkhead doesn't seem right) parallel to the boat's lines, to which the forestay is chainplated.

We don't know if the moisture has infiltrated into the bulkhead or into that chainplate mount. We hope that neither of them will have to be repaired, though we have accepted that they may be. Either way, the deck coring in these very small areas will need to be removed as well. Any tips or suggestions on how to deal with this area? Any special techniques on removing the core where the power tools likely won't reach? What are the chances that where the forestay attaches is wet? (obviously a tough question without being able to see her!)

(And as a very special favour, does anyone have a moisture meter we could borrow to use for this project? )

So here's the plan:
- Dettach the forestay. We'll be rigging an alternative system with the halyard and some sort of bridle system running under the bow and held in place by a line around the aft of the keel.
- Remove the pulpit, running lights, forward cleat, chocks, the water deck fill cap, and *sigh* the forestay chainplate.
- Drill through the inner fibreglass layer and cut it away. We'll probably start at the forward end of the v-berth, working aft until we reach dry wood, and then deal with cutting out in the bow locker.
- Grind out all the wet wood and clean with acetone
- Fit cardboard to the cabintop to determine dimensions for new balsa core.
- Buy 1"-square end-grain balsa matting, and cut to match the cardboard.
- Leave small electric heater and fan running for a week or two waiting for the outer layer to dry. (Will this be enough time, also assuming that we've laid a tarp over the foredeck to keep rain out, but allowing for substantial airflow?)
- Wait for a weather window of two or three days of dry weather.
- Coat inside of outer layer with polyester resin (only small areas at a time) wet balsa core with resin, and stick to the roof. We're estimating that once all of the prep work as been done, this should only take a day with the two of us doing this. Is this reasonable? And of course, we'll have good ventilation, and safety gear so as to not asphyxiate ourselves
- Coat the underside of the core with resin, and resin-in the fibreglass matting. (Another day alloted for this) Smooth out the bubbles, and wait for it to cure.
- Fair(?), sand and paint
- Remount all deck hardware

Please forgive my ignorance on this topic. I've worked with new fibreglass projects before, but with a foam core, and never on a re-coring project like this. I've found this link to a Triton recore but can't seem to find any on how to do this from the inside. Anyone have any links?

So here are my questions:
? Are we being impetuous and foolish to consider a substantial fibreglassing job in the wet Vancouver spring? If we have good heating and ventilation, will the high level of ambient air moisture be detrimental to the results, even if we are inside? Apart from the leaking pulpit, the boat is remarkably dry - there's no musty smell at all, no mold or general dampness.
? How many poor fishies are we going to kill as we weren't intending on hauling? We have a shop vac and we're hoping to set up plastic sheeting to keep any sanding residue from escaping the forward hatch or into the salon.
? Where can we find balsa end-grain matting in the Vancouver area?
? How big a section can we do at one time? With gravity working against us, I'm concerned that when we're reattaching the core that the balsa will sag a bit, resulting in poor bonding to the outer layer of fibreglass, and again with the inner layer to the core.
? What on earth do I do about the forestay chainplate? Can it stay in? Can we simply cut closely around it, remove all core, and fill the edges with epoxy, and then glass around it? Or as we're using a polyester resin (I think) will this have adverse repurcussions attaching to the polyester resin, or in future repair work? This is on the assumption (possibly wrong) that its mount is dry. Ack!
? What weight of glass will we need? How many layers will need to be applied? How many layers can do be done at once without heat buildup becoming an issue?
? This is probably a ridiculous question, but should we avoid walking on the foredeck completely without the core and inner layer?

Advice appreciated for this nervous newbie!

1974 24' Swiftsure
"I have always known that at last I would take this road, but yesterday I did not know that it would be today." - Narihara
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