Thank you, David, for the info on baffle holes.  A couple of sources mentioned 1/4" ply, but I just happened to have a piece of 3/8 okoume that was exactly the right size given the I could cut the bottom corner off as you mentioned. 

Annie: Yeah, I dunno.  I think that I'm going to have to put the water weight as close to the keel as I can get it.  I'm chickening out.  No doubt I'll think of your advice every time I have to root around in the v-berth for food I could have stored under the settees.

David Tyler wrote:I echo what's already been said about the settees being the wrong place for water tanks - but hey, it's your boat and your decision.

Water is heavy stuff, and can develop a lot of momentum. Is 1/4" ply thick enough? Are you aware of the special resins intended for water tanks? Ordinary epoxy is not quite the thing, apparently, but I didn't suffer any ill effects, and there wasn't any tainting once the epoxy had cured.

Cut off the corners of the baffles. That's enough for the water and air to flow where they need to. Short copper pipes, wrapped in glass and resin, make good connections for hoses: take-off, filler and vent, at minimal cost.

With both David and Annie wrinkling their noses at water tanks under the settees, pehaps it's best to lay out the options.  I'm truly open to ideas. Here are the guidelines/goals that led me to the settee locations.

1) I have no desire to stow lots of bottles and jugs.  I admire those who go this route, and I appreciate how it protects larger water supply from contamination and keeps plumbing to a minimum.  But knowing my personality, I would hate it.

2) I do intend to install a watermaker. Perhaps folly, but along with the jug thing, it's a bullet I'm willing to bite in terms of complexity and energy use.  After several years' cruising, I may love or hate that decision.

3) Non-pressurized freshwater water to galley and head sink.  Foot pumps in each location.

5) My bilge is quite shallow. There's not a lot of water that could fit in there, plus the keel bolts are not something I wish to cover up with complications.

6) Weight distribution.  This is what led me to the settee location as opposed to others, and perhaps this is where I'm being either naive or unduly concerned.  There are other places for me to put these tanks.  There's plenty of room under the v-berth, and plenty of space just aft of the companionway bulkhead on either side of the engine room.  If I didn't go with the settee locations, it'd have to be in these places.  

But I've already moved the mast and it's weight forward, plus I'll have all that ground tackle in the forepeak.  I don't know what this boat is like in terms of sea kindliness - I've had only a short sail on her in Long Island Sound.  Perhaps my worry about weight in the boat ends is unwarranted?  

Which leads to another question: if I weren't storing water under the v-berth or just aft of the companionway bulkhead, then what would I be storing there? A spare anchor and rode?  That's heavy.  Canned goods? Those are heavy, too. Spare bags of marshmallows and extra pillows?  Not so heavy...

So if I don't want to carry spare jugs... does the v-berth/under-cockpit combination make more sense than under the settees?

I get a lot of my inspiration to keep going from reading Tim Lackey's boat restoration project logs over at Lackey Sailing.  His work is clean, his explanations clear, and his diligence impressive. Check out his complete restoration of Snow Lily. I did notice that his sanding takes a LOT less time than mine, and his surfaces look much better.  I reached out to him to ask about his equipment set.  He responded quickly and with great info.  His biggest recommendation was for a Porter Cable 7345 5" Right-Angle Random Orbital Sander.

Several things:

1. These are not to be confused with the palm-sized random orbital sanders.  This is a big tool - too large to get my hands fully around the motor housing.  It looks like an angle grinder on steroids.  I'm 5' 10", not REALLY out of shape, and have average man-sized hands. And using this thing overhead will certainly have me taking a break every five minutes.  Okay - every two minutes.
2. I thought I'd be smart and get the Porter Cable 97455 - the same thing as the 7345 but with dust collection. That means it has a shroud and the sanding pad is hook & loop with 5 holes in it instead of a no-holed pad that takes adhesive-backed discs. 
3. Mistake. I should have gotten the regular 7345 instead, like Tim said. The 97455 clearly was not designed with dust collection in mind, and the shroud completely blocks your view of what you're doing. It does collect the dust, but it's not worth the money or encumbrance. (Those little palm ROS are designed with dust collection in mind - there's no shroud, and the back of the sanding pad rides against a seal creating a great vacuum, with the 6 to 8 holes really pulling in the dust.  Again, the big right angle ROS is a different beast.)
4. Also, Tim was very clear that the tool really want cloth backed 5" 40-60 grit sanding disks.  You can't get those in the dust collection (hook and loop with 5 holes) type. You can at best get paper backed, 60 grit.  They don't last nearly as long.
5. While a Right Angle ROS does put out dust, it's nothing like what an angle grinder with a sanding disk or flap wheel does. It's much more polite to the surface.  It's slower, yes, but not slow like a palm-sized ROS.

 

With the starboard saloon area mostly sanded and ground free of all the old stuff, I'm able to begin installing the settee/watertank.  Since I am having trouble visualizing all the corners and bits, the order of operations here is a bit off.  

I'm putting the front (the inboard longitudinal portion) of the settee in first, since that's the only shape that I know for certain.  I'm leaving the forward bulkhead off for now so I can design my way ahead as I go.  Not ideal, but I lack experience with all the funky corners and floors and soles and angles up there. So for now I'll fill in the area under the settee/watertank with baffles and whatnot, and let my brain ruminate on the other edge.

I'm planning on three athwartship baffles for the watertank, out of 1/4" ply, generously glassed. You can see the layout lines in the images above. For those of you with experience: how many baffle holes and how big? Do I need any holes through the middle of the baffles, or will scalloping along the hull be enough?

Darren Bos wrote:

An alternative to the brass barrel pump Annie linked to might be a kayak bilge pump.  They're also barrel pumps, good at passing solids, and can be had for a fraction of the cost.  They seem durable enough as I've abused them in the bottom of kayaks and dinghies.

Thanks for that, Darren.  I'll look into those if a nice brass one doesn't turn up on Trade Me.

Scott Dufour wrote:The forward side of this locker will also serve as the aft side of one of the two integral water tanks under each settee.  The forward head bulkhead will do the same thing on the port side.  With these two bulkheads in place, I can start laying out those tanks and mocking up the whole saloon layout.

Scott, are you absolutely sure you want to put your water tanks under the settees?  This is probably some of the best and most accessible storage on the boat.  When I sailed Badger, we would carry a year's supply of food on board, most of which was under the settees in the saloon.  It was so easy to get at and with a decent 'ready use' arrangement in the galley, I never needed to go under the settee if we had guests or the off-watch berth was occupied.  And, of course, keeping to the KISS principle, plastic containers have so much going for them.  Large water tanks can potentially leak or get contaminated (from bad stuff brought from ashore) and are much more difficult to keep clean then smaller plastic containers.  And they need baffles, more plumbing, etc, etc.

I suspect that this is one of my more bizarre caprices - I'm sure you've thought it all through!