Travel 2020-2021
Water Tanks — Part III — The Wreckoning
We’ve learned a lot of lessons.
First, the 4″ segmented TiN coated blade for the Fein Multimaster is the secret to this job. See this from Multifit Blades. The technique of scribing the line carefully with the blade oscillating, followed by running the tool slowly back and forth works really well. A little pressure is enough to start cutting a a layer of metal. Eventually, you break through the metal and can follow the starting line, finishing the cut.
The tank’s walls seem to be 3mm thick, about 0.13″, which makes it 8 gauge aluminum. The blades say they’re good to 11 gauge, so, we’re pushing things here. I did finish cutting a pretty nice 21″×21″ opening. I’ve deburred the edge, so it’s not razor-sharp. I have good access to the interior of the tank.
As you can see...
There’s a bit of yoga involved, since it’s barely 27″ deep. But I can fold up pretty compactly.
I tried some “blind” cuts: sawing up under the edge of the tank where you can’t really see what you’re doing.
The blind cutting worked out well, but you have to have a good grip on the tool, and a lot of patience. It’s not a thing where you can reach a long way inside the tank and hack away hoping for the best. You need to be close and solidly braced.
Originally, I thought I might be able to design a set of rigid tanks that would fill the space. That idea now seems way too complex. The more time I spend, the more I realize how constrained the space is.
The current thought is two tiers of flexible bladders. A piece of plywood can divide the tank into upper and a lower berths. Bladders tend to be less than 10½″ tall when filled, dictating the height of the layers in here. The pointy bit at the bottom-most 3″ can be blocked by a triangular floor. This leaves 24″ to be split into upper and lower berths for tanks.
I think it could be as much as 56 gallons, if I can find the right bladders. And if my estimates are correct. Pragmatically, it looks like the Plastimo 16658 is 115 cm long and 105 cm wide; which is close to the top triangle: 42″ long and 40″ wide at the aft end. This is 30 or so gallons. Underneath it is room for at least a 10 gallon tank; possibly enough space for a Natua FT911121 which is 14 gallons.
Next steps? Measure and mark the location of the shelves to separate upper and lower. Get some plywood and epoxy paint and self-tapping screws and build the shelf. Then. Bladders. Then hoses and hose-clamps.
And once that’s done?
The port side of the saloon has to come apart. That’s going to be (I hope) easier to get the top of the old tank completely off. And (I hope) easier to order a set of 4 tanks, each 33″×17.5″×11″. Many lessons still to be learned.
Getting to Done
For me, my day job things are rarely “finished” and “done.”
There are a lot of folks who can go home knowing they filled all the orders, dropped of all the shipments, closed all the tickets, and got things completely done. All the way done — for the day. Tomorrow there will be more, but those things are for tomorrow.
As a writer and a software developer, I often struggle with the tradeoff of “Good Enough.”
Intellectual property — books and software — aren’t ever really “done." There’s always more to revise and expand. But. There’s a publication date and a marketing campaign. So. At some point, I have to stop fussing and call it done. Or “done for now.” Or “good enough.”
The grand list of boat jobs — as a whole — is never done. There’s a long list of things to do and it rarely shrinks.
But.
Each job on the list is finite.
The task may be very large — for example, rebuild the water tanks — but it’s still finite. There’s a definition of done. Once the tanks hold water and the berth is reset for guests, we’re done. Close the job. Move on to the next job.
The done part of this sailing life is highly satisfying.
A few months ago, CA decluttered the lazarette to remove old lines we weren’t using; lines filled with mildew. She also chucked out one of the two tiny danforth anchors for the dinghy.
(We have no idea why there were two. Any why Danforths? Mushrooms make more sense for an inflatable.)
And she got rid of the tiny fender we didn’t know what to do with.
Decluttered. Done. Everything else in the locker has a defined purpose on the boat. And we’d used it over the years, meaning it wasn’t some kind of “maybe we might need that” spare.
We have our checklists of jobs. The cold, snowy days of February are for planning the work, buying parts and tools, and dreaming of sailing.
Water Tanks, Part II
The reciprocating saw (known to us as “Maxx Damnage”) let me make four long cuts in the space of a few hours.
Sadly, once we’re past the easy part, the new cuts involve less accessible places. And a less destructive saw.
The DeWalt reciprocating saw is good, but still doesn’t have the tight clearance the Fein Multimaster FMM250Q does.
I’ve got one of the semi-circular blades and I’m learning how to cut along the line over and over again until the blade finally pokes through the metal. It’s important to let the saw do the work and not force it.
The tank seems like it’s 10-gauge aluminum. The ABYC standard is 0.090″ to 0.125″. I haven’t measured, because it doesn’t really matter.
What does matter is that is’s slow going.
Today I made two 21” cuts to clean up the opening.
The process is loud. I mean “hearing protection required” loud.
After all, the aluminum is a vast resonating surface, connected to the hull of the boat, which is an even more vast resonant structure.
I spent time laying down, reaching into the tank. I don’t think I can reach up under the top all the way to the front of the tank. The tool is heavy and it’s a long reach.
I’ve ordered some of the larger size (4″) semi-circular blades for the Fein tool. These are described as suitable for thicker, non-ferrous material. If they work, I’m going to use them to slice away as much of the lid as I can. Consistent with not dropping the saw. This means parts of the top may remain in place because they're nearly inaccessible.
I looked at using the reciprocating saw from underneath, but the blade would collide with the fiberglass structure above the tank and that would be very, very bad for saw control and blade life.
Two more cuts with the Fein tool and we can start looking at fitting cardboard mockups in there to see how much tankage we can assemble through the 21″×21″ hole.
Or.
If the new blades are dramatically better, I may try to remove more of the top of the tank.
Worst case is two plastic replacement tanks. One little pointy one forward and one big chonker that’s about the size of the hole, but slides aft a few inches, leaving a little gap right at the forward edge of the opening. The forward tank would be (almost) entirely hidden, but the aft tank would be visible and accessible.
The triangular space forward of the opening is awkward and small. I suspect it’s on the order of 6-8 gallons. From the leading edge of the opening after, there’s at least 50 gallons of space. But. Dropping tanks in to fill that space is a real puzzlement. I think I can fill it with some 3-D bits and pieces of tankage and plumbing. I’ll be drawing sketches while I wait for another weekend.
(If you check back to Water Tank Replacement, you’ll see a volume estimate based on partial measurements. My current predictions are still based on still-incomplete measurements. The plan evolves.)
