Blog

How many gallons one of our tubs can hold?
We are trying to figure out how big of a water heater do we need.

in you case, 500liters (132 gallons) is the full volume of the tub.
You can subtract 15 gallons for the bather and another 15 if you do not want the water to overflow from top.

You can adjust the amount of water as you like.
Recently, in the land of “up to the shoulder soaking” is becoming popular the half-body bathing (keep the water up to the waist).
In this case you would be able to soak for longer periods and enjoy the minus ion atmosphere originated by the steam rising from the tub.

Hello,
I’ve been really interested in your wooden soaker tubs. I do
have questions about the tub that would help to re ensure the tub wont
leak. If all is answered, I would love to get one!!
1. what kind of joints are used for the wall panels and kind of glue. it
looks like there are many panels glued up to make the height of the walls..
2. what kind of joint is used to connect the floor with walls….
If you can anwser these question with any drawings would be great…

Thank you for your interest in our japanese soaking tubs.
Please find enclosed some pictures of our standard details. Click on the thumbnails for an enlarged view.

we laminate the wood using wood dowels and epoxy resin (+
curing agent). There are no metal parts.
Adjoining planks are cut together so the cutting angle matches perfectly.

the corner joint is realized with tongue and groove + epoxy resin.
long stainless screws are used to provide extra sturdiness.

Honestly, our tubs do not leak. If you use it regularly (everyday or every other day) your tub will work perfectly without any maintenance.
The only thing you should pay attention to is the fact that wood tubs are vulnerable to dryness. If you leave the tub unused for long periods it may crack. It is difficult to determine exactly at which point critical conditions are reached. It depends on air temperature/humidity, ventilation, heating equipment etc.
In any case, when you leave the tub unused for a week or more (let`s say 4 days or more as a doublesafe), leave 10cm of water inside and you won`t have any problem.
Do not hesitate to contact us for any question.

We do enjoy our hinoki tub, although we have had some minor cracking with some black growth on the outside of one of the corner joints. We’ve also found that hair and skin cells seem to stay floating on the surface even though we always shower before entering.

I am sorry you are having some problems with the tub.
About the dust staying afloat, I do not think it is a problem of the wooden tub, although chances are that when you drain the tub, small particles attach to the wood more easily than it would be in the case of an enamel or acrylic tub.

I think you can get rid of these light particles in 2 ways:
1) letting the tub overflow from the top
2) using a thin net to skim the surface of water

About the mold and cracks, please send some pictures, I`d be glad to advice.

I am enjoying my tub, which is installed on a deck outside my house. I was wondering if it is OK to put some sort of sealant on my tub, like the kind of sealant one would apply to teak wood, for example. Or, should I just leave it as-is and cover it up to make sure it doesn’t age too much because of the sun, etc.

I am glad you found a good solution for the tub.
If you apply a coat on the wood note the following:
– The tub will loose its natural “soft” touch
– The tub will loose its aroma and its skin-soothing properties
– You would have to seal it inside and outside (including bottomside) to prevent unbalanced behaviour
– Due to the oils contained in the wood, the coat may not stick uniformly and may detach. Consult also with the maker of the coating product.

Generally we recommend to use it untreated or apply a natural oil to hydratate the surface of the wood.

Additionally there are also some non chemical clear wood treatments which last one year and provide extra protection against mold.

Please let me know if you need some product.
If you have a specific problem, please send pictures of the tub and the installation conditions.

Thank you. If I do not treat it, will it deteriorate more quickly than if I treat it? I like the way it is but am worried about it deteriorating. I am having a cover made for it to keep it out of the weather. However, it got quit a bit of sun last year and cracked in some places. It does not leak, and the cracks are probably natural and not a problem. I like the way it looks now that it has aged for one year. I just wanted to make sure that I’m not supposed to be treating it with something. If there is a natural oil that I should apply, please let me know.

It is not necessary to treat the tub and usually japanese people do not apply anything.
In case you want to restore the original shine you can apply our hiba oil with a cloth, like you would do waxing a pair of leather shoes.

for purchase please refer to:
https://www.bartokdesign.com/2-products/wood_tub_cleanerconditioner.php
and for more specific information to:
https://www.bartokdesign.com/0-blog_news/new_product_hiba-oil.php

Please keep the tub protected from direct sunlight and if you cannot, leave the tub full of water to prevent dehydratation and cracks.

I am measuring the niche where I will be placing the hinoki tub. How precise should the dimensions be?

We build with a tolerance of +/-1mm, anyway be aware that wood is a natural material and tends to shrink and expand with the change of seasons.

If you place it against a wall, be sure to leave a 10mm clearance all around to ensure air circulation (see details page).

Hello Bartok Design,
I am a specialty contractor in Seattle Washington and a Japanese friend of mine who has a Hinoki Ofuro says that it leaks. I took a look at the tub and all the boards look in good condition, but my friend says that the water leaks between the boards at the seams.
Your website mentions in the question and answer section that cracks can be fixed, but it changes the asthetics of the tub.
Does the tub need to be taken apart and resealed or is there a way to stop seam leaks with some other product? Any information that you could give to help save this wonderful tub would be greatly appreciated.

Thanks you for your mail.
Hinoki tubs do not leak unless there is a crack in the wood.
Cracks are caused by dryness. They can be repaired with a sealant:
1) simply clear silicon: it allows movements of wood and it becomes invisible as the crack closes again after normal humidity level has been restored.

2) epoxy putty: it is water resistant and with color similar to wood. But as it is hard, wood balance becomes altered.

Another cause of leaks is poor joint construction. There is not much you can do about it apart for caulking all the inner corners (floor and walls.)Use mildew-proof clear silicon.

It is very difficult to disassemble the tub and most surely you will have to replace some parts. It might be worth the work if you create double tongue/groove rims at every joint but again, the main problem is whether it can be taken apart without damage or not.