Episode IV: A New Core
November 2005 --
It's important to focus on how nice it will be when it's done.
I'm on another f__ing mission. Gee.
After this winter I'll trust this boat, except for the keel, as it'll be the only critical element that I haven't rebuilt.
So here it is, just before dropping the sandbags
onto that little section of balsa core.
Lots of epoxy gooshed up through the cracks overnight, and there's a layer of epoxy all over everything, with a very interesting "sandbag texture" from the plastic bags.
It really looks like hell.
Before you decide that I've lost my mind,
here's the rest of the plan:
I'm going to sand it smooth with 36 grit, and epoxy tape over the cracks. I'll epoxy Knytex tape down the center and down each little side arm, radiating from the pedestal and creating a slight dome shape. Then I'll epoxy 1/8" thick sheets of prefab fiberglass over the entire thing, right up to the edge of the existing non-skid, and put new non-skid on that.
The dome shape will encourage water to run off to the edges,
where a 1/8" deep channel of original gel coat (around the edges of the
will lead to the drains.
I've been standing in this spot
for over eight hours,
it's November, it's past midnight
and it is really cold.
Really Cold in California means
the 40-50F range.
I'd been using Fast hardener,
because it was too cold to use the Slow stuff,
and I was running low on hardener.
So at this point I called it a night.
While crawling back to look for epoxy drips under the sole, I found this. It's the rudder stop block, which blocks the stop peg on the steering radial wheel so the rudder doesn't turn too far.
It looks like someone let go of the wheel while in reverse, because it
takes one heck of a shock to do this. I had noticed a discoloration around
the block when looking through the bottom skin of the sole, so the glass
tabbing might be pulled away.
Great. I needed something else to fix.
Well, with the engine, fuel tank and steering out, this is the time to fix it.
I smeared grease all over the hose.
This was tricky, because it's really easy to make a big mess with grease, and I don't want grease to interfere with the epoxy between the sole glass and the FRP core, but I *do* want it to prevent the epoxy from gooshing down inside the boat, and I *do* want the hose to come off easily after the epoxy cures.
The blood is just for color.
I'd originally planned to protect the area with a bunch of masking tape, but during the prep part of the day realized that it just wasn't going to happen.
There wasn't enough room to manipulate the tape into place,
so this was the best idea I could come up with on the spot.
I was really careful to get the grease as thin as possible, while still filling the gaps in the hose texture. After carefully slipping it through the FRP core plate, I cleaned the FRP right up to the hose with acetone, and slid the assembly over the rudder stock.
As it turns out, it did the job.
This picture was taken the next day.
No epoxy gooshed down onto the backing plate for the bearing, or around the hose on this side. However, I forgot to look at the other side, and haven't tried to pull the hose out yet, so there's still a possibility that I did something dumb. If so, I'll just have to fix it.
That's the plan, anyway. I think it will
For now, though, a big front is moving through and it's going to rain most of the the week.
I sure am glad the core is done and sealed up.
There are other projects that need to get
done before the cockpit can be finished,
so I'm going to have to look at it like this for a while. The epoxy taping can wait for the right weather window.
As the lid pieces were set into place, they were covered them with trash compactor bags and sandbags.
I had prepared eight sandbags,
with a total weight of 210 pounds.
They're just sand from the hardware store, double bagged
trash compactor bags.
The idea is to push down for a long time, and let epoxy
slowly goosh up
through the cracks.
Here's a plug for REPLACETONE from Tap Plastics.
It really made this job better.
It's non-toxic and safe to use on your skin,
unlike Acetone or serious solvents.
I've become slightly sensitized to epoxy resin
and hardener, and when I get some on my skin I want it off fast.
Having this stuff around was really nice.
For structural elements,
I used 3/4" marine ply.
Maybe there's something better, but I'm not trying to redesign the boat.
If I seal it into the boat properly,
it'll outlive my heirs.
Of course, I don't have children,
but why split hairs.
I'm really pleased with this.
At the top is a plywood ring to surround a Beckson port, which will give me better access to the steering system for maintenance. The port won't be that big, as there'll be an inch of epoxy inside the ring, and the screws for the port will be embedded in epoxy. The port will be protected by the propane locker.
Both the pedestal and the rudder thrust bearing are cored with solid prefab FRP from McMaster-Carr. That should make the areas really strong, but more importantly it will never rot if I get a leak.
There's balsa at the very front and back.
I tried to make the plywood around the pedestal fit under
the edge of the old lid, and that took an entire day
of tweaking with a belt sander.
The piece in the back just sits in there, and I'll pack the edges with epoxy.
Note that the wood and FRP blocks are lightly scored to improve the physical bond.
I had to choose between vinylester resin
or epoxy. Given the large voids that need to be packed with putty, vinylester
made sense because it doesn't get hot when it kicks and it would be faster
to fill the gaps. However, I'm not expert at adjusting ratios to compensate
for time and temperature,
and didn't want to make this into an experiment. I also didn't want to deal with the fumes.
Epoxy forms better physical bonds with existing
materials, and I'm familiar with it.
However, it'll kick off hot if I'm not careful.
To prepare, I set up this little shop on the bench. The drop cloth is a heavy trash compactor bag.
I can't move my feet once I start making a mess this big. It would be horrible to walk across the deck to fetch something, and then discover that I had a glop of epoxy on my shoe.
So everything's here: Two gallons of epoxy, Fast and Slow hardener, two large canisters of colloidal silica, 200 disposable gloves, dixie cups and plastic buckets, 100 rags, large trash can, fifty mixing sticks, plastic paint trays to set goopy things on, acetone, Replacetone, screwdriver, hammer, utility knife, 20 syringes, 20 plastic putty knives, steel putty knife, a piece of hose, grease, eight large sandbags, cigarettes, lighter, ten bottles of water, camera.
I should have brought a small bottle of tequila
and a bucket of fried chicken. (grin)
I'm starting in the early evening and will work all night.
The temperature has been 65F during the day and will get down into the high
40's at night,
which will keep the epoxy from kicking off too fast and will give me time to work without panic.
I have a big halogen work light, and a 100W heat lamp pointed right where I'll be kneeling.
I started off by painting the edges with thin epoxy.
Back under the edge, there's still little bits of dried
out old core material, that needs to be
fully saturated with epoxy.
The core pieces are set in a thin putty of
epoxy and colloidal silica.
It needs to be thin enough to flow out of the way when necessary, but thick enough to fill gaps in the uneven surfaces and stick in place.
Note that I drilled holes
all along the old core edge.
The holes were filled with
a thin epoxy putty.
Again, the putty was thin enough to flow,
but thickened up as much as possible for strength.
I put a little bit in, then worked around the edges.
Then I'd lay another section of core, giving the edges time to start to kick, then come back
and shoot some more epoxy in.
Here's a picture of thin epoxy putty for the FRP block
under the pedestal.
As the core was laid into place, the putty flowed around and under all the pieces.
The cold temperature really helped, and gave me lots of working time.
The area around the rudder was a concern.
This job would be a lot easier with the rudder out of the
boat, but since the boat's in the water that's not an option.
I need the rudder in the boat
to reinstall and align
the thrust bearing.
For this section of FRP core, I made a
super thick putty, so that it wouldn't run down onto the rudder stock.
The hole for the bearing was cut at an angle, to match the rudder stock.
I used a four inch section of hose to protect the area. It fits over the bearing section of the rudder stock and almost touches the edges of the hole.
I really like this picture.
The weather has been clear and cold,
but we did have a winter front move through which dropped some rain.
The awning setup worked fine, and everything's dry.
Fortunately, I have many random hunks
of lumber in my garage. That's why I keep my truck outside. You need to keep big hunks of wood in the garage, because you never know when you're going to have to
jack up the cockpit sole.
It's really cold, so I'm only using
Fast hardener. After hours of injecting epoxy around the edges and into all the cracks, it's starting to thicken up without cooking. Hooray.
I used a slightly thicker putty to put the lid back on.
I screwed up during my prep, and forgot to drill lots of holes in the old lid pieces. Unbelievable, given the number of times I thought about it. I also left my notched plastic spreader at home.
The idea with the holes is to ensure that epoxy gooshes out all over the place, to verify total coverage. So instead I had to spread the putty very carefully, lay each piece down, pry it back up and verify that everything was wet, then set it back down and push really hard. It worked out.
I waited until morning to do that last section of balsa core, because I was worried about running out of hardener and there aren't any stores open at 1 a.m.
With balsa, I laid thin putty down, then mixed up some epoxy with no colloidal silica and let it run down into the cuts between the blocks, then pushed it into place.
After filling in the edges and putting thin putty on top,
I covered it with sandbags.
The balsa wanted to float up, and the sandbags were very important to press down hard and goosh the epoxy everywhere.