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Kihada ichiban water repellent

Where can I get Kihada Ichiban?
You can purchase from us.
It comes in 3 sizes:
a) 7,000. JPY / 1kg + 4,500. JPY (Packaging + EMS) = 11,500 JPY
b) 26,000. JPY / 4kg + 9,100. JPY (Packaging + EMS) = 35,100 JPY
c) 97,000. JPY / 16kg + 27,000. JPY (Packaging + EMS)= 124,000 JPY
If you let me know your preference, I can send you a paypal payment request.
After sanding, apply in 2 coats before the first one is completely dry.

difference between shapes

Can you tell me the advantages and disadvantages of using an oval shape vs. a rectangle shape, in terms of comfort? And how many people could comfortably fit? Also wondering about the various heights of the different tub options you sent, If I used a seat, it doesn’t seem like the water would cover my body up to my neck. How does one do that?
Many questions I know! If I keep the water in the tub and just heat it up, how is that done? do you provide a water heater?
The weight when full of water…can you give me an approximate figure? Will my construction framer need to make the floor extra support to hold it?

I wish there was an ofuro I could try in my area! If you know of any public ones in the pacific northwestern area of USA, please let me know!

Japanese bathtubs originate from the technology of boat building. (which are actually build to keep the water outside and not inside!)
About the shape, the rectangular tubs evolved from the method of building boxes.
The round and ingot shape tubs from the manufacturing of buckets.
Therefore the shapes are different in their origin not only in the design but also in their functionality and purpose.
Ofuros have not been designed. They have been shaped by everyday use.
I think this is a splendid example of the expression “the form follows the function” expressed by the architectural modernist movement.

Said that, here I will mention some DEMERITS of the two shapes:
1) round, ingot shape: as the planks are orientated vertically and have their cross section (which is more porous) facing up: they are more prone in becoming stained on the section by black mold (but this is not always true out of the extra humid japan)

2) rectangular tubs: the corners unnecessarily hold some a larger amount of water..!
I am not sure I answered your question…

What is your budget? If you want to use it in 2 people you need at least 1500 of length.
But if you make it deeper and add internal seats… it becomes quite expensive.

Therefore I recommend to use it without seats – which enables to have a shallower tub and also use less water.

For the weight, consider that water weights 1000 Kg per cubic meter.
Therefore it depends on the sizes but a 1500x750xD600mm will hold 670 liters (670 Kg) when filled to the rim.
This translates in 120 p/sf so I think you would need some reinforcing if the bathroom is on the 2nd floor.

Sorry, we do not know of any public ofuro in the US (we supplied ofuros to Singapore and Hong Kong spas.)
For the question about re-heating the water, please check FAQ 71.

All the Best//


wood sealing

We recently installed a cedar Ofuro that was sealed on the outside only. Because it is on radiant heat it is beginning to check. Is there a sealer that you have or can recommend that would remedy the problem? Thank you.
Please note:
1) A wooden bathtub placed on a radiant floor will dehydrate and crack. No matter if the wood is coated or not.

2) Besides this, coating only one side only is never a good idea as the wood will be unbalanced and start to warp

3) In case of a japanese bathtub, we never coat it as it would lose its aroma. To make the maintenance easier we suggest to use a full penetration water repellent product (Kihada ichiban)

to solve the problem in your case I recommend:

A) to sand the outside of the tub to remove the coating completely

B) To keep the tub always full to the rim while the radiant floor is on. Even when you are not taking a bath

C) If you want, we can sell the water repellent. It prevents stains and the formation of mold.

Please let me know if you have additional questions.

about reheating of the water

Our client was mentioning wanting the ability to fill his tub in the evening and soak, and then be able to use the same warm water in the morning. Is there a system that re-heats the water or maintains a higher temperature?
In Japan most of the hot water heaters are equipped with a re-circulation circuit and have a small pump built into the system.
But of course we cannot export a HW heater with the tub (you would not be able to do maintenance or find spare parts) so the only way is to build a system ad hoc.
This can be easily achieved by putting together some machines used for spas such as a pump, cartridge filter and post-heater (gas, electric or heat pump).
US is the land of private pools and spas so you have the best selection of equipment with makers such as certkin, jandy, pentair, waterways etc. If you prefer a low tech approach, you could cover the tub to avoid heat loss due to evaporation and in the morning you can add 10 liters of very hot water (60deg. centigrade) to raise the temperature.
Please let me know if I answered your question.

day-bed completed!

Here is the leather mattress and cushion completed. As you can see two full cow hides have been used for the left/right side without joints.
The frame is also complete and the graphic keyaki wood grain is providing the perfect accent for a very simple and classic design.

click below to see the other 6 photos with details of the frame and mat.
Check also the crowdfunding campaign page:


finishing the daybed frame

Here are the photos of the finishing phases of the “Michael” day bed manufacture

The legs pegs are positioned to take advantage of the thickest section of the frame


click below to see the other 13 photos of the manufacture!

Alternatively, check the crowdfunding campaign page for more details and to purchase keyaki daybed:


update about the daybed!

The manufacture of the keyaki daybed is proceeding smoothly. Here are the pictures of the progress with comments.

1) hinoki slats, 15mm thick, cut to size
click below to see the other 9 steps

new year card 2018!


like a walk with your best friend,
like the smile of a child,
like a japanese ofuro,

may the New Year be “round” and “square” for you
and … filled with aromatic hot water!

All the Best//
Bartok design Japan Co.

the first sunrise of 2018!

As from Japan we are the first ones to enter in the new year, I am pleased to send you the sunrise of 2018!

I saw it from Ino-yama, one of the 7 “small fuji” mountains of japan, located in Marugame city – Shikoku island.
The sun rose at 7:16 between the mountains and a low tiara of clouds. For this reason, the sunrise was particularly beautiful.

Happy New Year!!
May the 2018 bring you health, happiness, prosperity and serenity!


japanese day-bed crowdfunding campaign


Alas I was able to share with you and the world our new project: building a day bed using japanese wood and traditional woodworking techniques.

You can find more details and even purchase discounted daybeds here:

here below is the main inspiration source:

I have a business card holder made of wood. 100% wood. The button to open it, the spring, the hinge are all made with wood essences which are most suitable for the function. Not a single part of metal. not a nail, not a screw. I have been using it daily for 18 years and all the joints are tight and the movements effortless like day 1. The new daybed will be manufactured with the same concept: no metal parts at all.

And here I am with Kitajima-san, the passionate furniture maker who will produce the daybeds.
The daybed will have the same size of a kyoma tatami mat (1910x855mm) and will be topped with a full grain leather mattress.

The sale price (after 2018/3/1) will be 6,000 USD + shipping fees, while the crowdfunding price is 4,500 USD + shipping fees (maximum 10 units). Therefore if you are interested, contact me for any additional information and hurry up to secure yours!

here is the keyaki lumber that will be used to build the frame.
As is explained in the indiegogo page, the daybed originates from the design process and mail conversation with a Bartok design client, Michael. It is thanks to him if this daybed will have a stylish and sharp design, without compromising with the seating an sleeping comfort.
Thank you again Michael!

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