# What would be involved in making a wooden bath tub?



## datawog (Mar 6, 2012)

I've been looking for small tubs to fit into a tight space, and the Japanese ofuro soaker tubs caught my eye, mainly because of the depth. Who needs legroom as long as you can sit up to your neck in hot water?










But they carry quite the heavy pricetag, definitely more than I am willing/capable of spending ($6600 for the tub, $400 for the shipping crate, $1500 for shipping expenses, plus $250 for customs... that's most of my budget for my entire project), and they're not entirely ideal for what I need it for (ofuro tubs are traditionally made from hinoki wood, and left unfinished so it can release its natural oils into the water as you bathe. Any soap you use would soak into the wood and cause discoloration, since the tradition in Japan is to clean yourself outside the tub and use the tub for the sole purpose of soaking. I need this as an all-purpose tub).

Would I be able to make my own wooden tub? I was thinking something like a 36" cube, maybe even smaller. It would have to be varnished probably many, many times (I recall cocobolo over at Gulf Island Building saying that good quality boat hulls would get upwards of 20 coats, since I don't foresee it rubbing up against any docks maybe 10 or so would be good). Another thing with the unfinished ofuro tubs is that they have to be kept partially full of water to keep the moisture level constant so they don't dry out, crack, and warp. I'm assuming(/hoping?) that as long as I'm using properly seasoned wood, completely sealed off from moisture via varnish, I shouldn't have to deal with warping. Or at least not too much of it...

Then there's these rounded, vertical-plank tubs:










This style has a certain aesthetic to it that I find pleasing, and depending on how round I made it it would reduce the amount of water I'd need to fill it, not having corners and all.

Both of these styles pose their own problems when it comes to me figuring out how to put them together. For the round one, I'm guessing the wood planks would have some kind of tongue-and-groove attachment going on, glued together, then circled with the metal bands and cinched for strength and support. I'm not entirely certain how to do that. Plus, if I wanted it to have sloped sides (which, I kinda do, one thing I do not like about the ofuro) I'd have to work a taper into the planks, and haven't the foggiest idea how to calculate how much of one. For the ofuro tub, they do have a page where they show parts of the construction process (http://www.bartokdesign.com/japan/3hottub_manufacture/), but they're not all that clear to me. The tongue-and-groove joints at the corners I get, but each side of the tub is made out of 2 or 3 separate pieces of wood, attached to one another by wood pegs. Exceptionally long wood pegs, sure, but still... how do those keep the water from leaking out between them? Do they just pound it down real hard until it's practically molded to the lower piece? Would I be able to use a single piece of wood instead? What sort of wood, and what thickness, would be ideal?

I'm a pretty decent hand with tools, my dad's a carpenter and a woodwork teacher so I've picked up quite a bit from him over the years. And I'm certainly a measure-twice cut-once person, so if I can figure out how to do this I think I should be able to pull it off.


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## joecaption (Nov 30, 2011)

Call me cynical but for the life of me I can not come up with a single reason anyone would even want one never mind building one.
There's hundreds of other chioses for a tub that would be water tight and would work with standard plumbing.
Anything out of the ordinary is going to be expancive because they just do not make enough of them to make it cost effective.


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## tinner666 (Mar 14, 2005)

I would think 2"-2-1/2" T&G planks,. maybe cedar, using West System Epoxy. We've built some boats this way that have 20+ years under their belt.


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## cleveman (Dec 17, 2011)

Just get yourself some 8' 2x6's, douglas fir. Cut some in half.

Make a frame with dowels or pocket screws out of the 4' and 8' pieces. Stagger the joints. Explanation:

Put a 4' on the floor flat, and call this the end of your tub. Now lay an 8' at a right angle to the 4'. Call this your side. Now lay another end, then the other side. You will have a frame 4'-5 1/2" wide and 8' 5 1/2" long with staggered joints. Now join these together somehow.

Put down a good coating of glue on what is on the floor, and on your next panel. Set the two together, and screw them together. Stagger the joints.

Stack panels until you are about 2' up in the air, or about 16 courses. This will be 48 2x6's. This can't cost too much.

I need some help with the bottom of the tub. 

Build the whole thing on a slab?

Put a double or triple layer of plywood down as a bottom?

You could fancy this hillbilly tub up a bit by putting some decorative strapping around it.

Post a photo of yourself in there with a crimson union suit and smoking a cigar. If there is room, some busty babe might look good as well. Scratch that. Just post a photo of the busty babe smoking a fat cigar.


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## daveb1 (Jan 15, 2010)

Those wooden tubs do look nice, but I would be concerned with how to clean/sanitize a wooden tub.


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## BigJim (Sep 2, 2008)

Didn't they use the old wooden tubs in the olden times like the old west? I think it is doable and would look good, I would be concerned about the depth though, it might make it a little rough getting in and out if the sides are too deep. I think one made looking like a strip canoe would really be sharp. When you start your build take a bunch of pictures, we loooove pictures.


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## datawog (Mar 6, 2012)

Joe- my problem with the tubs that I've looked at for this space is they're extremely shallow- around 2" shallower than my current tub. Even in a full-sized tub, I hate the fact I can't slide underwater without sticking something else up in the air. Get my shoulders underwater, my knees are poking up. Straighten my legs, everything from the chest up is out. Since the intended space is so small, the commercially available tubs I've looked at that can fit the space aren't much more than half as long, which wouldn't even be so bad if it weren't for the lack of depth. If I were able to make my own tub, I could match it exactly to the dimensions of the space and have it be deep enough to get a nice soak out of it. And if I can't make the wooden tub idea work, I think I'd rather just put in a small shower stall. Having a bath tub you can't actually take a decent bath in just screams 'colossal waste of space' to me.

Tinner- thanks for that info on the epoxy. Probably a few coats of that inside and out should do the trick nicely.

Cleveman- thanks for those tips, it's really helping me visualize this coming together. I may actually be able to build this out of red cedar boards that were milled out of the big tree my Nana had taken down last year... I'll probably have to do a bit of bartering and canoodling, but I think it would be pretty sweet to bathe in the remains of a 100 year old tree felled from the property I was born on.

Dave- once it's got a few coats of epoxy + varnish, it'll be a breeze to wipe down. With the traditional style ofuro with no sealant I can see that being an issue, but with a 5mm coating overtop I'd imagine it would be like wiping down glass.

Jiju- Good point on height. Measured my leg, and I'd be able to step in/out of something up to 30" tall. Then sat down and measured from the seat to my shoulder... 25". Plenty of wiggle room there. Though looking at some of those ofuro tubs with the benches on the inside, that seems like it would be pretty nice... think I'll stick with my plans of 36" and also plan a little step-stool to help me get in and out. Though I'm thinking of decreasing the footprint down to 24"x36", or even 24"x30". I could probably even go down to 24"x24".... but I would still like to stretch my legs out just a _little_ bit, water consumption be damned.

Have no fear, when this goes underway there will be many pictures to be had. This is only one portion of a much larger project for which I am still in the theoretical planning/budgeting phase, trying to figure it all out... I'll hopefully be able to start work in the next 6 months. Until then I'll be poking around here, asking questions, sketching up plans, researching materials and techniques... all that good stuff. Make sure I am nice and prepared before I start swinging a hammer. But hopefully you'll see me pop up in Project Showcase before too long.



cleveman said:


> Post a photo of yourself in there with a crimson union suit and smoking a cigar. If there is room, some busty babe might look good as well. Scratch that. Just post a photo of the busty babe smoking a fat cigar.


For making me laugh, I promise that once it is completed I will do whatever I can to get a busty cigar-smoking woman into that tub for a photo op. :thumbsup:


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## horseonthefly (Mar 14, 2012)

On stitch and glue (plywood) and cedar strip kayaks they put a thin layer of fiberglass around the outside. Seems like you could use either technique to build your tub, just seal the inside instead of the outside. There's a ton of information available on the web about both methods.

Here's a video of them wetting down the fiberglass on one.

http://www.youtube.com/watch?v=SMSKuLCCNC0


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## Blondesense (Sep 23, 2008)

datawog said:


> Having a bath tub you can't actually take a decent bath in just screams 'colossal waste of space' to me.
> 
> Jiju- Good point on height. Measured my leg, and I'd be able to step in/out of something up to 30" tall. Then sat down and measured from the seat to my shoulder... 25". Plenty of wiggle room there. Though looking at some of those ofuro tubs with the benches on the inside, that seems like it would be pretty nice... think I'll stick with my plans of 36" and also plan a little step-stool to help me get in and out. Though I'm thinking of decreasing the footprint down to 24"x36", or even 24"x30". I could probably even go down to 24"x24".... but I would still like to stretch my legs out just a _little_ bit, water consumption be damned.


If your gonna go this small, I'd do a mock-up first and sit in it a while. See how comfortable it is. You may find you'll want to tweak the angles of the seat or back etc.


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## t_mott85 (Nov 23, 2010)

There's an episode of Dirty Jobs where mike goes to NYC to remove and install the large water tanks that are on all the tops of the buildings. Maybe you could pick up some ideas from this large scale construction technique.

I would also think for strength reasons perhaps stick with a simple perfect circular design. Once you figure out how many vertical pieces of wood you need and cut to length you would figure out the angle on each piece and would just make the same cut on all of the pieces. I would also think you would need some kind of banding around the outside to hold the structure intact. Of course iron or steel comes to mind but I wonder if you could use thin strips of wood that you could laminate and glue around the structure so that when it cures it's just all wood.


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## datawog (Mar 6, 2012)

That fiberglass cloth is pretty neat... was hesitant when I saw the big white sheet over the canoe, but then they add the epoxy and it completely disappeared! Wonderful, wouldn't want to lose any of the grain pattern. Does the fiberglass just add strength to the project, or is there more to it?

A mock-up probably would be a very good idea... just slap something together with plywood, hang out in there for an hour and see if I cramp up. Would be especially handy for figuring out how much of a slope to put in the back rest. Fortunately I'm a pretty teeny guy (5'3" and maybe 130lbs soaking wet) so a teeny tub would work just fine for me. Measuring myself seated from heel to back, I'm only 36" long, and that's with my knees completely straight which isn't all that comfortable. From sitting sideways in my current tub, I know I could fit in something as short as 24" without discomfort, but I'm aiming for an end result of 'surprisingly luxurious' over just plain 'well, it's not _bad_...'. So, I think 30" will be the minimum so I could actually stretch my legs a bit, rather than just sitting like I were in a chair. The inner seat would also have to be somehow removable... back to the water usage bit again :icon_rolleyes: but if I've got a seat raised 6" above the bottom of the tub, then I'm filling the tub an extra 6" to cover up to my shoulders. During times when I'm forced to watch my water use and not fill the tub anywhere near full, I'd like to be able to take the seat out so I can scrunch all the way to the bottom and make the most of what water I do have. I was thinking that paired strips of wood on either side would do well, just have a plank that I would slide in before filling, with the upper bracket having a downward lip to keep the seat from shooting out from under me and floating to the surface. Briefly considered an 'adjustable' seat that could be swapped between brackets at different heights, but since I want the bottom narrower than the top (again for water reasons) I'd have to have a separate seat for every level. I think I'll just figure out a height I like and stick with that.

I actually got the initial idea for a wooden tub off the Gulf Island thread, where cocobolo made that fancy-schmancy red cedar hot tub. So yes, certainly taking inspiration from larger projects. I'll try to watch that water tower episode, that is certainly building on a GRAND scale and if wood can be made to hold thousands of pounds of water without springing a leak, I think I can scale it down to work for what I'm going for. I'm not 100% sure on making it completely round, though that may be easier. I'd rather go oval, or even teardrop-shaped. Back to water consumption... I really don't need it to be as wide as it is long. My ass isn't *that* huge :wink:. All that extra space at the sides would pretty much be wasted water. Plus it would take up more room, which isn't exactly readily available.

Speaking of laminate.... The thought had crossed my mind before, of perhaps making the entire thing laminated? Use many, many, many thin pieces of wood and gradually build up the shape until the walls are 2"-3" thick. That way I'd be able to contour it to exactly the shape I want, and not have to worry about joins except where it connects to the bottom, though I would still have to taper each piece. If I could get 8' strips of wood, then the entire circumference of the tub would be a series of overlapping circles rather than short planks pieced together, which would add plenty of strength would it not? This also has the potential of looking looking really, really nice, either by playing with the contrast between light/dark woods or splurging on a really fancy veneer for the final layer.


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