Jatoba for a desktop?

[scott vroom]

I'm building office furniture for a home office and am considering jatoba for the 2 desktops (30" x 5' and 30" by 8.5'). My only experience with jatoba is a small sample board I bought a few years ago which I planed and finished with Arm-R-Seal. It was beautiful, and definately suitable from a hardness standpoint for a desktop. 4/4 rough is $6.53 in my area, not much more that the QSWO that I typically use for desktops. Has anyone used this species for a desktop, any how did it turn out? At 2820 Janka it's more than twice the hardness of white oak and I imaginc hard on the tools, but it's a small project so not concerned...I've got spiral cutters on the planer and jointer. Any pitfalls I should be aware of?

[pat warner]

Has a tendency to change shape.
And with enormous force. So it can change the shape
of the frame or frame & panel structure it's screwed too.
So acclimate, select well, maybe T&G, and flatten before the install.
Do a crummy glueup with bad sticks: Expect adversity.

[Jamie Buxton]

A few years ago I did a complete kitchen in jatoba and cherry. All the doors and drawer fronts were frame-and-panel. The panels were solid cherry, and the frames were jatoba. The project came out beautiful, if I do say so myself. The doors stayed flat, unlike Pat's experience. One thing which surprised me is how much jatoba darkens with time -- even more than cherry.

[dan sherman]

I haven't done a desk with it, but I have done end-tables. The key to working with Jatoba in my opinion, is letting the wood acclimatize to the shop, as well as letting it rest between millings.

[Peter Quinn]

Its heavy, its hard...its hard. I've found some boards don't want to be tamed, others behave much more nicely, a desk top should be fine as you aren't generally significantly changing the size/shape of the original boards. Take a wide jatoba board and start ripping it into small parts like rails and stiles, can be challenging. One issue I've had is checking. I made a bench seat for a mud room in a clients home, made the bench first, worked out the mud room over a few months, went back to size the bench, had sealed the ends with shellac, wrapped in shrink wrap to keep it more stable, the ends had checked significantly. I had extra room on the length, had cut out all checks pre assembly, but if you are used to working with white oak I'm sure you are familiar with end checks. The acclimation is good advice....assuming you have a few years on this project, because wood that hard doesn't acclimate that quickly IME. It gives up moisture or takes it slowly. You can acclimate walnut or ash in a few weeks, jatoba not so much, so you get what you get IMO. If you have quarter sawn material available it seems to behave generally better than plain sawn, the stuff with real visible interlocked grain can thwart all efforts at flattening. And it gets about 10 shades darker, like a heavy vandyke red working toward tobacco brown over time, which I happen to like.

[Peter Quinn]

I haven't done a desk with it, but I have done end-tables. The key to working with Jatoba in my opinion, is letting the wood acclimatize to the shop, as well as letting it rest between millings.

Those pice look just post finishing, no? Any pics today for reference to show how dark it gets?

[scott vroom]

The acclimation is good advice....assuming you have a few years on this project, because wood that hard doesn't acclimate that quickly IME. It gives up moisture or takes it slowly.

I've got 4 weeks to complete the project and haven't purchased the wood. I'll check the MC at the hardwood supplier, in your opinion what's a desirable maximum MC? 7-8%? I can't screw this up, maybe I'll use QSWO on this job and stock up on some jatoba and let it sit in the shop for a year for use on a future project.

[J.R. Rutter]

It is also difficult to measure MC, at least with an pinless meter, due to the high mineral content. If you can pick boards yourself, try to get the lighter (weight) ones. Try to do minimal flattening - start with flat stock. I have two jatoba topped coffee tables that I made and they have done well over time.

[dan sherman]

Those pice look just post finishing, no? Any pics today for reference to show how dark it gets?

Yep, they are post finishing photos. I don't have any newer ones, as they are only 8 months old and don't get much direct light in my family room. They are darker than they look though, as the photos are washed out.

[pat warner]

As dark as it appears. (http://patwarner.com/images/jtable.jpg) Only on close inspection can you recognize Jatoba.

[Mike Cutler]

Scott

Yes it can be used as a desktop.

In the linked post I have three large projects, for me at least, made of Jatoba.
http://www.sawmillcreek.org/showthread.php?23141-Arts-amp-Crafts-Style-Door/page2
The first is our library door. This is 6/4 Jatoba and is as straight and true today as the day I built it. We heat our house with wood, so this door has definitely seen wide variations in humidity levels.
On the second page of the thread I show two library shelves. The bigger one is a full wall unit (10'x7'). The bottom shelves are 10' long, and at the max radius of their curve it is 27". The smaller unit has 6' long shelves that are about 14" deep.
The next project I made from Jatoba is a large blanket chest featured in a book.
http://www.sawmillcreek.org/showthread.php?46908-Blanket-Chest-Tack-Trunk&highlight=
This is a very big, read heavy chest.

If I had any advice it would be to pick your boards carefully. Look for as close to Q-sawn, or Rift sawn as you can find. Select boards that require a minimal amount of mating because my experience has been that these boards release a lot of energy when ripped. Select your stock well.
Don't be against using hidden metal fasteners if necessary. This wood is strong and if it decides to shift, it's going to shift. A glue joint alone may not suffice.
If you do use metal fasteners, you will need to pre-drill the holes. This stuff is almost as good as aluminum at having a screw hole tapped in. Use a drill bit just a couple sizes smaller than the requisite size for a tapped hole in metal and you'll be good.If you need to use threadserts, you'll need to have a couple sacrificial ones to use as "taps", and you will definitely the correct tool to put them in.

It's a hard wood to work with, but it finished superbly for a weekend warrior type like me. General Finishes Arm-R-Seal was all I needed.

[Joe Calhoon]

We just built a door unit from Jatoba at the clients request. My first experience with the material. The project turned out great but it has a few things that are different than any other material we have worked. It is very heavy and hard. I would say this is the heaviest door in this size we have ever built. Next time I will consider a pine core. It moves a little but seemed to settle down after everything was assembled. We had good stock. Out of 350 feet I would say only 5% was twisted. Our slot and tenon corners were too tight to assemble. We had to file all the joints to get them to fit. When we build from white oak the joints get a little tighter but nothing like this. The glass beads had to be predrilled and hand nailed. gunned nails would just bounce off the material. It machines nicely and almost has a burnished look after shaping. It will wreck high speed steel planer knives.

I would like to make some furniture from it.


Joe
290866

[scott vroom]

I've read enough here and on other sites to realize jatoba is not a good choice for this particular job. I'm now looking at sapele for the desktops. It's got potential movement and interlocking grain issues, but nowhere as severe as jatoba. Overall should be a safer bet for a job that I cannot affort to mess up. Opinions welcomed.

Dan and Pat, really nice work on your jatoba projects!