Read directions from the Tatara Website in Japan:

Here is another document with details on coverage and drying time according to wood density:

Watch this cute video of Hassui Ceramic application. It’s in Japanese, but a video is worth a thousand words!

Can Woodspirit Handcraft ship Hassui outside of the United States?

No. We do not ship internationally due to flammability, cost, and shipping rules. In Europe there are two sellers Felix Bouchet in France and Yoav Kafets in the UK.

When will you get the next shipment?

February 2024 we received a new shipment. Join the Hassui Ceramic newsletter to get future updates via email (see below).

Where do you ship Hassui Ceramic?

Due to the flammability of the product, we only ship within the US. UPS Ground for 48 states. For Alaska and Hawaii, we ship USPS Parcel Select Ground.

What is Hassui Ceramic made of?

Hassui Ceramic is a silicon based polymer. The finish is made up of molecular silicon suspended in isoparaffinic hydrocarbon and isopropyl alcohol. As the alcohol evaporates, an inert glass-like coating is left behind.

What is Hassui Ceramic good for?

Hassui Ceramic Wood Finish is excellent as a non-toxic, tasteless, non-yellowing finish for wood. It keeps the natural look of the wood while protecting the wood from dirt, food oils, and environmental degradation.

What ISN’T Hassui Ceramic good for?

Hassui Ceramic is not a thick, filling, or encasing finish. It is not like epoxy or sap or oil. It is thin like rubbing alcohol. It penetrates the wood, so it feels like a slightly slippery wood rather than a plastic coating. So don’t expect it to fill up holes, cracks, or porous wood. It builds very thin layers with each coat. In terms of staining or coloration, if you are using dark wood or are very particular—do a sample first to see if Hassui is right for your application. Hassui is not bullet proof. Try urushi lacquer if you want a natural waterproof sealant.

What brush do you recommend?

A chip brush works nicely, nothing too fancy as it will wear out over time.

What do I clean it up with?

Rubbing alcohol and a paper towel cleans up your brush pretty well.

How do I open my container?

Use a box cutter knife to very carefully pry the inner seal out of the spout. Be sure to replace lids tightly, as the product will evaporate easily if left unsealed.

What is the shelf life of Hassui Ceramic?

If the container is left unopened it will keep indefinitely. Once the container is opened the finish will stay uncured as long as it is kept from humidity and air. Make sure your container is well sealed.

What can I use Hassui on?

We have used this finish on wooden spoons, potato mashers, cups, bowls, canisters, tool handles, & countertops. Others have used it on tables, chairs, stools, puppets, ukuleles, boats, walls, etc. It is appropriate for hot and cold liquids, alcohol, and food contact.

Are there volatiles in this product?

Yes. Make sure there is ventilation when applying the product and use gloves in case of drips. Read all safety instructions included before beginning application. Safety Data Sheet.

Can I use Hassui on Cedar/Birch/Maple butcher block countertop/exotic wood/etc?

We always recommend buying a sample to do a test before applying Hassui to your piece. Application rates vary according to the wood species as well as the look of the finish and how many coats you choose to apply. We used Hassui Ceramic on a Birch countertop from Home Depot. We applied 3 coats and used a little less than 1 fluid ounce per square foot for all the coats combined.

How many coats should I apply?

This depends on the look you want and the wood you are coating. We apply 3 coats to our Maple wood tea canisters. The third coat leaves a slightly glassy finish. For frequently washed items like cups and bowls we use at least 5 coats, making sure the first few coats heavily saturate the wood and fully curing before use. After a few years your piece can be renewed by reapplying a coat or two.

What is the coverage per square foot?

The porousness of your wood will affect the coverage—the more holes/pores in the wood, the more finish is needed. The first coat uses the most, with subsequent coats using quite a bit less. We recommend doing a sample to test coverage on your piece. The label lists approximately .5-1oz per square foot.

There are glossy spots where the wood grain is more dense—what do I do?

To avoid glassy spots, gently wipe the finish with a clean cloth where the finish looks glossy before it dries.

Can I apply Hassui Ceramic to veneer wood or will it dissolve the glue?

Hassui Ceramic can be applied to unfinished veneer and it will not dissolve the glue.

I’ve watched demonstration videos and it appears that the application is quite easy:  a decent natural brush (chip brush even) and a couple of thin coats…looks almost like applying a wash. Any tips on getting a smooth finish?

I think the main thing for a smooth finish is a well prepared surface ie sanded and dust free or knife finished and a clean brush. The density of the wood plays a major role as well. After using Hassui, clean the brush with rubbing alcohol and wipe dry. Some tiny silicon particles might remain on the hairs, but if you can wait long enough for the particles to dry/cure (5 days?) they come off the hairs easily by washing the brush with soap and water. Or you just deal with the tiny particles by sanding between coats with 600-1500 grit, when the piece is dry/not sticky to the touch. That is what I usually do. The dried/cured Hassui has an interesting slippery feel. As you use it you will get used to its properties. The first coats absorb like a wash, but then the layers start to build and drying time gets longer. I do at least 3 coats, more often 5, and even more for cups. You can feel when the piece is “done”. The shine will lessen through use. And you can always add more coats in the future.

Can I apply Hassui over another finish? I'm in the process of making hardwood tabletops and desktops. Do you think Hassui might work on top of a hard wax oil or even a traditional oil such as boiled linseed oil or Danish oil?

I have personally put Hassui over old plates, bowls, and cups that were finished with linseed oil as well as ones finished with what we used to use—Treatex which is very like Osmo. It worked just fine—didn’t seem to affect or dissolve the undercoat—however these items were fully cured before applying Hassui. The Hassui laid on top and created a gloss right away. I think the only concern would be the bond of Hassui on the surface of the previous finish. Hassui is designed to penetrate the wood and bond there, so there could be an issue with the Hassui not being as durable when applied on top—meaning sensitive to abrasion and needing recoating more often than if it was allowed to soak in to the unfinished wood. Just make sure to let it cure to full hard before use.