Sat 28 March - warm enough to core & glass

The area under the stbd settee had a spot that was very tough to chisel out. The outer skin ended up getting punctured. A plastic sheet was taped on the outside of the hull and then the area was faired from the inside using epoxy thickened with West Systems 410 fairing filler. This will be easier to sand when the work is done on the outside of the hull. Inside was then covered with neat epoxy and 2 layers of 17 oz biaxial cloth rolled in.














While the settee was curing, the stbd quarter berth was cored. Below shows the area by the hull valve. The area around the valve was filled with epoxy thickened with colloidal silica to isolate it from the balsa core, and provide structural integrity for bonding the fiberglass inner skin.















The same area looking aft shows the balsa jigsaw puzzle.















Once the stbd quarter berth was cored, the stbd setee cured enough to bond core. The view below shows the area with core bonded. The area will be trimmed and sanded prior to applying the inner skin.














Here is a view of the transom area with new the inner skin on both the transom and the stbd side. The holes for the backstay chainplate were drilled so I could trace a template for a doubling plate in the corner. Even though what is there now is much stronger than the original balsa core with a marine plywood doubler, I plan on bonding a pice of 1/4 inch fiberglass in the corner to serve as a doubler. I'll need to sand the glass threads to get a smooth surface for bonding the doubler.















The area below is a view looking in the stbd cockpit locker by the engine control. The new inner skin can be seen tabbed to the bulkhead that seperates the engine compartment.















I bought a new fiberglass exhaust tube but don't like the wall thickness. I plan on bonding a 1-3/4" tube inside the 2" tube to strengthen it similar to the original exhaust tube. Rain is predicted for Sunday, so that's all the work for this weekend.

Glassing in the Stern & Chipping Rotted Core Elsewhere

21/22 March turned out to be another ok weekend for fiberglass work with temps in the high 40 degree range. This is good since during the week it was in the 20s and 30s.

The transom area finally has the inner skin with two layers of 17 oz biaxial fiberglass cloth bonded to the new core. This is like working as a one armed paper hanger trying to keep the cloth flat on the vertical transom surface while hanging in through the cockpit lockers. The picture below shows the view looking at the intersection of the transom, deck and starboard side. The fiberglass lip at the seam will be sanded to take out the bumps prior to bonding the inner skin on the side.















The view below shows the transom in the area behind the lower rudder gudgeon. You can see the seam where the glass cloth was split in two pieces to make it manageable to hang. There is also a lip that overlaps the bottom to tie the transom to the main part of the hull.
















The starboard quarter berth show where 2 layers of 17 oz cloth are bonded to the outer skin. This will be ready for new core next weekend.














The same area with another view showing the engine intake valve. I decided to leave the valve in place since I would need to cut it to get it out. It's a good valve, so will be building up the area around it to isolate it from the balsa core, and tie it structurally to the surrounding fiberglass skin.















Here's more bad news. There is plenty of rotted balsa in the stbd settee just forward of the nav table. The area is the last that will be done this season, meaning that there is more work to do forward of this under the fuel tank and moving forward next year. I don't think the boat will fall apart if I leave those areas undone for another season.

Another "Warm" weekend to Bond Core

The second weekend in a row and March 14/15 provided some great 50 degree weather to work on the boat. I continued to cut the balsa pieces to match the contour of the transom. The photo below shows the final transom core pieces bonded with bracing material to hold it in place so the Core Bond could cure. Although hard to tell, the bracing board is approximately parallel with the horizontal bottom of the boat. This was completed on Saturday.















On Sunday morning I removed the bracing and sanded the areas where I dropped core bond in the section forward of the transom. This needed to be a smooth surface for bonding balsa core. The core bond sands pretty easily compared to using a filler of thickened West Systems. I used large sheets of paper to trace the cutout sections just forward of the transom on the stdb side. The paper tracing was then transferred to the balsa core and the pieces cut using a knife.
Below is a picture that shows fitting up the pieces. The edges were sanded/cut as needed. The gaps between pieces aren't real critical, as they would be filled with core bond. Note that the balsa pieces were fabricated as one large piece that I then cut into smaller sections no larger than 12 inches. This allows the pieces to conform to any irregularities and insures a good bond to the outer skin. The picture below is a view looking straight down in the stbd cockpit locker. The top of the picture forward and left side towards the keel.



















The view below shows the area in the cockpit locker bonded. Note the core bond between the core section joints. I left a tab of the old inner skin around the entire new core area so when the fiberglass is bonded, it will be bonded over the tab to provide structural support. This means that there are still some areas with wet core. I'll live with it, since I know the boat won't crack if there is hull slamming in rough seas!




















This is my chance to make sure the exhaust is never again the culprit contributing to wet core. The picture below shows where I created a dam at the bottom of the hole where the fiberglass exhaust tube will be bonded. I filled the area with thickened epoxy. The dam leaked so I have a little puddle forward of the hole. It's just a cosmetic problem, and nobody but me and the world reading this blog will ever know about it. The top of the picture is stbd and right side is looking aft. The white triangle is sunlight overexposing an area - hey I held the camera below in the locker, so this was a blind shot!




















Remember that the area on the stbd side by the transom and the backstay chain plate was like mush? The photo below shows the new and improved cored area. The section with the upper bonding tab I left on the stbd side was dug out, ground clean using a wire brush on a flexible shaft, then thoroughly dried with a heat gun (it was very wet). The void space was filled with core bond. That way if water was coming in by the seam, it will be stopped before reaching balsa. The core bond was also used as a layer to isolate the transom from the new core on the stbd side, again to prevent water migration if there ever was a problem in the future. The photo below is looking up at the intersection of the transom, stbd side and deck joint.
















The center area above the transom is shown. Note that there used to be a piece of plywood strengthening the area behind the rudder gudgeons. That's the gap that shows along the top seem. This won't be needed with the stronger fiberglass plate that is there now. Before bonding the inner skin, I'll use thickened epoxy to fill the area and provide a contoured surface. Plan is to bond the inner skin as a flat surface, then bond a fiberglass tape to connect the surface with the adjacent tabbing. It's just too hard to try and work all the complex angles with a big sheet of resin soaked 17 oz biaxial cloth.

Note to self - no backing plate on the stbd side padeye for the back stay (see just the nuts and washers in lower left portion of picture). Fix that!
















Starting the "easy" areas to core. This means working on your knees instead of hanging in a locker upside down. Warren was working on grinding out the inner skin from the stbd quarter berth while I was working on the transom. He needed a little calibration on how to use the Fein tool because he punched through the outer skin in a few places.... more exterior sanding, filling and fairing work to do. I continued this work on Sunday after the core bonding.
















Here's another potential water source. The engine intake hull valve does not appear to be isolated from the core. Plan is to dig out underneath leaving the valve in place, then build a dam using a 6" diameter plastic mixing bowl that has been cut off leaving about a 2 inch lip. The dam will be filled with thickened epoxy and provide an area where the fiberglass cloth can be bonded to for structural strength. I'd replace the vale, but it is in great shape, so no sense destroying it taking it out. It has been routinely lubricated, operates freely and shows no sign of corrosion.

Spring temperatures so Transom work starts again

I worked on Rhapsody today for the first time since the 1st week in December. The temperature hit 60 degrees so it was perfect weather to do some core bonding. However...it's supposed to snow tomorrow. I never took pictures of the fiberglass plates bonded to the transom, so started with that. The picture below shows the backstay chainplate backing and swim ladder backing bonded to the transom. I predrilled the holes and used throw away hardware to hold the sandwich compressed while the bonding material set. I used a two part vinyl ester resin called "Core Bond" for the bonding, except for the rudder mounts I used thickened epoxy. The problem is I now have the fasteners on the rudder mounts frozen in place and need to drill out the bolts. I was able to unscrew the fasteners where I used the Core Bond. The Core Bond is very easy to work with because it is already the consistency of peanut butter, and only requires the mixing with hardner.


Back in December I had bonded all the fiberglass plates and bonded balsa core between the fiberglass places used for the backing on the rudder gudgeons. The next two pictures show views of the center transom area where the bonding was done. I'll end up sanding, filling the bond voids at the joint seems and fair it before applying the inside fiberglass biaxial cloth.





























Today I spent making the jigsaw puzzle pieces so I could fit them together and continue the core bonding work. It was a little tedious because of hanging in the cockpit lockers to make paper templates, cut the balsa core pieces, and trim them to fit. I ended up completing about half the transom on Sunday afternoon. Hopefully the weather next weekend will support finishing the rest of the transom bonding. Below are pictures after the bonding work today.

Preparing New Fiberglass Backing Plates

The replacement backing plates will no longer be balsa and plywood. I purchased two 12" square 1/2" fiberglass sheets and cut them so they can be inserted as core replacement in the areas where the rudder gudgeons, chainplate and swim ladder are mounted. This serves to isolate the balsa from the bolt holes, provides additional strength, and prevents the bolts from compressing the balsa. The picture below shows the pre-staged pieces ready to be laminated. The buildup includes 3 layers of 17 oz biaxial fabric so the final thickness is the same as the core.


This photo shows the assemblies after the glass was laid up with resin and cured. The pieces were covered with plastic and a board with weights to obtain a reasonably flat surface.


The picture below shows the pieces after the resin cured. The edges will be trimmed, the pieces sanded for bonding, and the hole pattern drilled prior to bonding to the transom. The fasteners will be waxed to hold these pieces in place while the core-bond cures.

Start Transom Reglass, Cut open stbd aft

The prep work on the transom is finally complete. There was a mixture of resin and wet plywood at the base of the rudder mount that was a real pain to chip out. Once the grinding of old material was complete, the areas was sanded, vacuumed, and wiped down with acetone... all while hanging upside down through the cockpit lockers. The picture below shows the transom with two layers of 17oz biaxial fabric glassed in.

I'll be using a product called "core-bond" to attached the core to the fiberglass. I didn't have it this weekend so instead installing the new balsa, I started cutting into the stbd side to recore selected areas. Below is the area just forward of the transom. The was rotten for about 18 inches forward. The core in other places was solid but soaked. This was difficult to remove so I decided to cut around the solid areas and will open it up to dry it out.


The photo below shows the upper area of the stbd side all prepped and ready for glass. I left a small border between the transom and the edge so I have a structure to fill with thickened epoxy to isolate the transom from the rest of the boat.

Below show where I cut around solid core. You can also see light areas at the bottom. This is where I ground the blisters on the outside of the hull.

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.