Still waiting on confirmation of a few final details before I can truly embark on fabricating the set of Modular Tansu that I introduced a couple weeks back. It’s been a slow process going back and forth discussing various details about the cabinet, so slow that I’m wondering if it’s really going to happen. Nevertheless I’ve been moving forward working out some more joinery and construction details which I thought I’d share.
First thing, the doors. Last time I mentioned the wood movement challenges of making a very wide door for the long cabinet, and shared that I’ve been pondering both a solid wood + joinery approach to making the door as well as veneered option. Thanks to all the folks who commented, it was interesting to get some suggestions that I hadn’t thought of before in regards to veneering, such as using hide glue and hammer veneering the panel. Other suggestions were to glue up the panel using epoxy and use a simple shop built setup for clamping/pressing the veneer.
I’m definitely partial to the solid wood route but for such a wide panel (nearly 1200mm or 47 1/4″) I’m leaning towards a veneered panel for the long cabinet. That said, I think I’ll go with the solid wood panel and batten approach for the two smaller upper cabinets. For the veneered panel I’m thinking I’ll use an mdf core and my own shop sawn veneer so that I can keep the wood grain consistent by taking it from the same batch of material as the rest of the cabinet. I’m also leaning towards epoxy for the glue-up for the sake of minimizing any wood movement that might come from using water based glues. Also here in Japan I haven’t been able to find a supplier of quality hide glue yet, which sort of takes that option out of the picture. Lastly, as a few commenters recommended last time, I can pretty simply setup a clamping/pressing system using some sheets of mdf and wood clamping cauls in lieu of buying a vacuum bag setup. I’ve done a few veneer glue-ups in the past using that approach but those were fairly small panels. For something considerably larger like this door panel, I think a vacuum bag setup would be nice, but the reality is I’m unlikely to do a ton of veneering in the future, so I’ve decided to stick with a shop built clamping setup, and just take my time to arrange a solid set of plattens and clamping cauls to ensure a good result.
Here’s a look at the inside of doors and some of their construction details:
The veneered door won’t get any supporting battens, just the two upper doors which will be solid wood.
On previous cabinet projects my go to approach for dealing with the cabinet back has been to use either tongue and groove boards or ship lap boards vertically lined up.
I really like the look of that style of back but it doesn’t offer much strength in terms of racking resistance, which for this current project is pretty crucial. So this time I’d like to go with a solid wood and batten approach. The battens (like those on the inside of the upper cabinet doors) would be joined to the panels with sliding dovetails, and mortised into the surrounding frame. This style of construction is incredibly strong and offers a ton of racking resistance. Especially for the lower long cabinet, I want to make use of this construction method to add as much strength to the cabinet as possible since it will be supporting the weight of the upper cabinets and all their contents. In otherwords I’m hoping this construction will offer a fair bit of resistance against the lower cabinet sagging under the weight of the other cabinets.
Here’s a rendering of how the backs may end up looking:
I could go with veneered panels for the cabinet backs, which would also offer a ton of strength against racking/sagging, but what’s the fun in that? Besides I think the sliding dovetail battens and solid wood panels will offer a ton of strength as is, and will ultimately be more visually interesting and much more unique than plywood back panels.
The other joinery for the cabinets themselves is pretty straightforward. The case joinery for lower cabinet will get hidden mitered dovetails just like the original that I built a couple years ago, and the upper cabinets will get pinned box joints in the same style as the old tansu cabinets that they are based on.
Here’s a shot of one of my antique cabinets with pinned box joints:
And here is a rendering of the box joints on the forthcoming upper cabinets:
For things like the shelves and inner compartment partitions I’ve also been considering joinery options. The shelves may or may not be made adjustable, but any vertical partitions will need to be fixed in place and for those I’m thinking wedged through tenons would be the best way to go:
I’m also thinking wedged through tenons would be a nice option for fixing the drawer dividers on the lower cabinet as well:
(There would also be wedged through tenons popping out of the right side panel as well.)
If it’s decided that the shelves should be fixed then I also modeled and rendered one side of the lower cabinet showing wedged through tenons for those areas as well:
It’s probably overkill to join each shelf with these joints, but I modelled in that way just to see how things would look. It looks a bit too busy to my eye, especially since the shelves are only 3″ apart. So, if the shelves are fixed I think I’d probably only do wedged through tenons on the very bottom shelf, while the upper shelves could simply be dadoed into the side panel and vertical partitions.
There are still a few more areas to deal with in regards to the joinery, but I’ll save that for next time. Really digging into the joinery and construction details for this project has been an interesting excercise. Like anything you design and build from scratch there are a ton of possibilities. The hard part is distilling the options down based on what is best for the project at hand. For the most part I think I’m closing in on the final design details for these cabinets… but I’ve also started exploring a whole other approach to building these cabinets by switching from a slab/casework construction method to all frame and panel. I’ll share more on that next time as well.
Thanks for visiting.
My two cents/ 3 JPY is that the through tenons on the sides do look too busy. And although they would be strong, the extra strength they give over blind tenons is overkill given how many there are.
On mdf vs solid wood for panels, I wondered for a bit whether panels of mdf would provide enough stiffness to resist sagging on that lower cabinet. I was thinking, for example, that I probably wouldn’t cantilever an mdf shelf very far. I looked around a little for technical specs and as a rule of thumb it seems that MDF is about 1/4 as stiff as white pine. Which might be a worry, but I’m thinking your panels would be so tall that either in use would be way overkill.
Don’t take my short investigation as gospel. But you might want to make estimates of how much weight those cabinets would reasonably carry and go from there.
I’m not planning on using mdf anywhere except for the core of the laminated door, which won’t be carrying any load of any kind. In that case all the mdf needs to do is provide a really stable substrate for the surface veneer. The rest of the cabinet, including the back panels, will all be solid hardwood of some kind, so load bearing will all fall on the stiffness of the wood along with the joinery/construction method. I agree though that MDF is a pretty poor material for anything needing to carry weight, especially when laid flat and used as a shelf.
The base of the cabinet is also going to get some reinforcement of some kind which I discussed in the first post on this project. Right now I’m thinking of reinforcing the long members of the base with brass bar stock, but I have yet to finalize the exact details. Overall though yes I’m putting a lot of thought into the weight that is going to be carried by all the cabinets as a whole, and the best way forward to support everything.
Ah, I see. I think that is a good strategy.
I’ve never tried to glue brass to wood and don’t know what adhesives might be best for that. Maybe a urethane glue?
Yeah I had thought either a urethane glue or epoxy. I used urethane to glue some aluminum channel to reinforce some hinoki slats for a ceiling a while back and it worked great. On a test piece I couldn’t get even a sliver of wood to break loose from the aluminum, so I imagine it should work pretty well with brass too.
Hey Jon!
I totally forgot to reply to the comment on the previous post. Veneering works with any glue that has sufficient open time, so something like Cascamite\Weldwood\Unibond also works, they should be sold in Japan. These glues are way stronger than PVA (used in marine applications for instance), so it might replace epoxy too. To prevent glues from seeping through there’s a thing called “sizing”: basically a coat of a very diluted glue is applied over a surface and let dry, and then veneers glued as usual. This works best with glues that bond to itself, so for PVA you might need to wait until it’s just tacky. It seems like you’ve settled with actual veneering process, but just in case check out the hot clothing iron method. It’s usually used with PVA, you just iron the veneer and it binds immediately, so a press isn’t required. It works because there’s enough heat to evaporate water instantly, but still below PVA temp limits. I used it on smaller patches of veneers that are tricky to press, and it works great once you dial appropriate temp on an iron.
Also, I have a question: how many fingers are usually used on bodies? I’m going through pictures of some dansus online and it seems like the number is usually odd. Is it random or there are some suggestions on sizing the fingers, like we have for dovetails?