More Transom Cutting & Vacuum Bag Bow

I did some more grinding with the Fein tool. This is a slow process but it will be worth it in the end ( I keep telling myself). Note the discoloration of the gelcoat, fiberglass and rotten balsa around the exhaust. The core all along the seam between the transom and hull is rotten. I've also started to cut into the plywood by the chainplates. There is also glassed over plywood about 9 inches wide by the rudder mounts that runs from the keel to the deck.

The next picture shows the outside holes where the lower rudder mount was bolted to the transom. When the bolts were pulled about 2 cups of water came streaming out.

The swim ladder was removed. This was bedded pretty well with no water entry there. You'll see my first "oops" where I cut a little too deep with the Fein tool and went through the transom. I'll fix this from the inside and do a cosmetic gelcoat repair on the surface.

While I was working on grinding the transom, I decided to start the vacuum bagging the bow to remove moisture. I drill holes from inside into the core in a grid pattern where the core measured wet. The area sounds solid and doesn't smell like the core in the transom.

Below is the completed bag setup. Some terry cloth towels were laid over the holes and the plastic was duct taped to the hull. A slit was put in the bag and the vacuum pickup duct taped on. When the vacuum is running, you can really see how tight this setup is. Time will tell if this approach works without a heat source on the outside. If not, I'll use heat too.


Ok - Saturday afternoon and back from the boat. Progress on the grinding the old skin, core and plywood is much slower than I anticipated. First - I took off the engine intake strainer. I suspect that this hull valve is NOT isolated from the core and is a mjor leak source. Check out around the edge of it. No work will be done on this section until after the transom is complete. At least this is accessible from inside.



Below is a pretty good shot of the rear skin with the balsa scraped off and the engine exhaust pipe removed. Still more work to be dome on removing the inner skin and the plywood by the rudder and stbd chainplate. Note all the rotten core on the bottom of the picture. I already emptied two buckets with the stuff.


Here is a view of the transom stbd side chainplate structure partially removed. It appears that the balsa core was laid up on the outer skin, the inside surface was then glassed with what appears to be two layers of fiberglass mat, then an angled piece of 1/2" plywood was glassed in on the interior surface for structural strength. Note that the balsa in this area is completely shot. I can scrape the rotten balsa out with my finger it is so bad. The same construction is behind the rudder mounting hardware too. This is a real pain to get out because I'm hanging at weird angles reaching in the locker and have limited access to grind the plywood which is wet, but still strong.

Making the first cut

It's always hard to make the first cut, but I did it today. I decided to work inside rather than outside the transom knowing that it will be more difficult. I wanted to minimize any exterior finish work that needs to be done. Here is a picture of the first cut.














There was water coming out of the cut fiberglass as the blade moved through the core. I used a Fein Multimaster tool that I borrowed from a friend. This uses a serrated blade like a saw and the tool vibrates. It also has a chisel blade that can be used for getting out the old core.


I drilled some holes with a circle cutter to get core sample on the stbd side aft. It looks like some of the balsa core there is rotten and will need to be replaced. Other core holes have solid balsa, but it is wet. That's all the time I have this weekend, so to be continued later.

Map of Wet Areas with Moisture Meter

On 20 October I used a moisture meter to map the contour on where the wet areas are located. A stbd stanchion is shown with the moisture meter and the contour line with moisture at the 15% reading on the meter.









On the port side, the primary winch is the source of water infiltration.















There are a few stanchion bases that also are a source of moisture.






The area by the anchor locker hinges is wet along the with port and stbd chainplate areas.



The stbd cockpit has moisture below the stbd side where the foot rest is located.


The area forward bow pulpit mounts are a source of moisture.

The following are moisture maps for the bottom. The entire std side below the waterline is wet. The source of moisture is the transom - rudder mounts, exhaust and cockpit drains. The area surrounding the keel is wet on both sides.

Rhapsody Hauled 15 Oct 2008 - start of off-season work

Rhapsody was hauled at Borden Light Marina on 15 October for the season. Last spring a moisture meter was used to check the deck and hull. The news was not good. The entire stbd side below the waterline is wet. There are also some wet spots on the deck. The transom sounds hollow and is delaminated.

After hauling, the bottom was pressure washed and inspected. For the first time ever, blisters were showing on the stbd side on the bottom over about a 4 foot area. These were not there last spring, and must be forming from moisture inside the core since the entire bottom was redone with new barrier coat two years ago. On Friday 17 October, the blisters were lanced to drain. They were opened up with a sanding disk on an angle grinder, then the area around each blister faired with an orbital sander. In the sequence of photos, you can see the depth of the barrier coat (4 layers alternate white/grey). Plan is to recore the area behind the blisters from inside the boat. I'll be borrowing a moisture meter next week and will map the readings on the hull.