Showing posts with label balsa core. Show all posts
Showing posts with label balsa core. Show all posts

Friday, December 18, 2015

Bad Boat Day

Some people have bad hair days.  When you are living on a boat you can have bad boat days (after all, we generally don't worry much about our hair).  Today was one of those days.  I guess I should have expected it having just had a nice positive with the move and partial installation of the hardtop...you know, yin and yang.

It all started when I got up this morning.  I usually make coffee before my wife gets up.  I grind some beans and put them in my AeroPress.  Then I proceeded to knock the AeroPress over, and the freshly ground coffee landed on the galley floor.  I'm a little grumpy before my first cup-o-joe, so this mess didn't help. I drag out the little shop vac and dispense with the coffee on the floor and grind some more. Fortunately there are no other mishaps, and I drink my coffee while checking the weather on the computer.

What?  Where did this 90% chance of rain in the morning come from?  Yesterday evening the forecast said nothing about rain.  I look out the window and sure enough, it's the one time the meteorologists got it right. Guess I won't be installing the window in the top today.  The forecast also showed that winds up to 15 mph were likely.  Now that the top is bolted on in the back, it probably won't just blow away; however, the front end is only resting on jack stands sitting in my cockpit.  After all the work we have put in on the thing, I figure the prudent thing to do would be to lash it down to the deck so it is held onto the stands just in case some stronger gusts make an appearance between now and when the front supports are complete.

I find some line and determine the D rings on the deck are a perfect place to tie it down as the line would be right across the front quarter of the top.  Then I remember that one of the D rings is a little loose.  Guess I had better fix that first. I wonder if I will need to make a backing plate for the D ring as I've found the backing plates on much of the hardware on this boat to be a little lacking. I open up the access panel to access the nuts on the back of the screws holding the D ring. Imagine my surprise when I find that not only was there no backing plate, there were no fender washers or nuts either. The screws were just dangling through the fiberglass like little sealant-coated metal stalactites. I look around and see no evidence of nuts or washers below them.  No metal, no rust, nothing. Apparently, the only thing holding this D ring in place was the failing sealant.  The only explanation I can come up with for the lack of retaining hardware is that I think the boat had been repaired in that area in the past.  I could see a worker going to install the D ring, getting the sealant down and then being distracted and forgetting to install the hardware.

Oh, and the sealant was failing.  Below the stalactites is a recess in the fiberglass.  This recess apparently has no where to drain and is full of water.  Hmm...wonder how long this has been leaking.  I go back up on deck and give the D ring a pull and out it pops with the bolts.  This is where I discover that the manufacturer didn't bother to seal the holes in the cored deck.  The result of this is that the balsa core (the deck is made of two layers of fiberglass with a core of end-grain balsa) is quite wet.  Actually, around the holes it passed wet a while ago and was more decaying now.

Cleaning up the D-ring mount.

I spend most of the rest of the day digging out wet and/or rotting balsa from three 10 mm holes using a bent piece of safety wire.  There is a trick for getting wet balsa core out of a hole where you can take an alan wrench or bent piece of safety wire, put it in a drill, and use that to dig out wet core from a hole.  But not in this case. The balsa core appears to be sealed into small-ish sections, with fiberglass dividing them and the D ring was mounted right over one of these dividers.  The wrench couldn't turn full circle without hitting the divider.  All I was left with was taking a bent piece of safety wire and tediously coaxing each little bit of balsa out of its hiding place. I did reach clean looking balsa about the time the sun was setting so now I need to let it air out and dry for a few days. Once dry, I'll do one last sweep to clean out any remaining loose bits and then fill the void with epoxy to make a permanent repair to the core and seal the core material so this won't happen again.

There was another little discovery while dealing with the D ring.  Remember that recess I mentioned that was holding water.  It sits at the top of the bulkhead that separates the hall and the shower.  While inspecting the bulkhead to make sure there weren't any other surprises, I found one.  The only saving grace is that it isn't too serious of a problem.  As I was "percussion testing" (a.k.a knocking on) the bulkhead wall in the shower, I hit one spot near the top and heard a slosh.  Not the click of solid fiberglass nor the dull thud of a delaminating fiberglass core, but the sound of water. The bulkhead wall appears to be fine, but water apparently made its way between the bulkhead wall and the plastic panel that lines the shower.  Looking across the surface of the panel, you could just barely see the slight bulge. Obviously the water needed to be let out.  The only solution I could think of, short of ripping down the whole panel, was to drill a small hole at the low spot of the bubble and let the water drain.

We have a fountain on our boat.

Not yet sure how to repair the panel or hole, but it does look like a nice place for a towel hook.

So, no work on the project at hand was done today.  Instead, it was spent preparing to repair other "discoveries".  Of course, I guess I can't complain too much.  If these problems weren't discovered, the issues might have become much worse, requiring much more extensive repairs. Such is life living on a boat.

Oh, and the welder I found did drop by to make a wood template for the supports so that was a tick in the positive column.  Guess I lied, a little work was done on the top after all.

Wednesday, July 15, 2015

It Worked.

You know, sometimes I even surprise myself.  This through hull replacement turned fix the cored hull seems to have turned out as good as I could have hoped.  In my last post I talked about how two through hulls were not put in properly on the boat and the negligence could have allowed water to soak into the core and cause delamination (a very serious structural problem on cored composite boats). As it turned out, there were actually three through-hulls that were apparently installed by the same people, but in one of the cases they got lucky and didn't drill through cored fiberglass.  The only evidence all three were done by the same folks were they were all related to the AC system (or generator to power them) and that they failed to remove the old bottom paint before installing any of the three the through hulls.  Ablative bottom paint isn't the best surface to try and create a seal against..since it ablates after all.

To fix the prior installation issues, I spent a lot of time with a small screwdriver, a Dremel tool, and even a hex wrench to remove any wet core material I found and create a void between the fiberglass skin layers. I could then fill the void with epoxy to seal the remaining core and create a better mounting surface for the through hull. Before adding the epoxy my wife and I, for good measure, packed the holes with silica gel (a desiccant) to pull out any possible residual moisture in the core.
We let that sit for a day or two as we worked on cleaning up the other through hull holes and located parts for another unexpected project.

Yesterday we continued work on these two through hull holes. We started by removing the tape and silica gel we had packed into the holes.  Did I mention that the location of these two through hulls is in one of the least accessible parts of the boat, directly underneath the stairs that lead from the salon to the starboard hull.  The only access is via a cabinet door under the desk and that door leads to a chase that runs aft under the stairs.  And these holes are located just about a full arms length from that cabinet door.  Add in the air conditioner lines, raw water pumps, and other hoses and wires that are run through this space, and working in it can be...well...a challenge.

View from the access location.
The short black posts are the wrapped PVC pipe
in the holes in the hull.

Using my Dremel tool, I drilled several holes through the inner skin of the hull and into the area where I had removed the balsa core material so I could inject epoxy into the voids.  I then took some plastic (trash bag actually) and wrapped two small pieces of PVC and inserted them into the the two holes.  These would create a mold for the hole I want to remain and allow me to inject epoxy into the voids without it all spilling through the holes and ending up on the ground.

I mixed up some West System G-flex thickened epoxy, placed it in a syringe, and began injecting the stuff into the holes.  I started at the bottom injection hole and would squirt epoxy in until I saw it come out the next two holes above it.  I then took some cellophane tape and covered over the lower hole and started injecting from the next holes up in order to try and prevent any air from being trapped inside the repair. Oh, and to see the holes, I needed to use an inspection mirror attached to a flexible shaft that I could wrap around whatever was convenient or have my wife hold and position to get a look at my work. It took about two full West System epoxy syringes worth of epoxy, and I have no idea how many colorful metaphors, to fill the area around each hole.

The holes sealed and ready for replacement through hulls.

The epoxy takes between 7 and 10 hours to cure, so I couldn't see the results of all the work until this morning.  When I got up this morning, I was a little concerned how easy it would be to remove the PVC "molds".  Luckily, they slid right out and exposed a very nice cylindrical hole lined with epoxy. The results look very nice and I'm sure this will keep the core sealed and provide a good structure for re-mounting the through hull. Hopefully we can get some of those re-installed tomorrow.