Joining an irregular, detachable modesty panel together and to an irregular shaped desk

Question

I've built an irregularly-shaped desk with irregular, five-sided cabinets. It now needs a modesty panel, but because of the unique angles and circumstances, I'm stumped as to how to attach such a panel within the design requirements.

The challenges:

1. Because this is fine furniture, there can't be any visible fasteners on the outside of the desk. Fasteners on the inside must be concealed and tasteful. The final piece will be stained, not painted, any patching and filling will show.

2. Due to the size of the finished desk, it needs to be able to be disassembled into smaller pieces for moving if necessary. That means that the two cabinets, the top surface and the modesty panel must be able to separate and re-attach in a non-destructive way. (ie. no glue or screws where the wood will wear out and not hold after repeated screwing and unscrewing.)

3. The modesty panel needs enough structural integrity to not fall apart when it is separate from the desk.

4. There should be some way to attach cables to the modesty panel, like a cable tray.

5. The modesty panel has three panels, each joined at very slight (5-11 degree) angles.

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Here's a top view with the desk top removed:

The three panels of the modesty panel as well as the cabinets are built with 3/4" birch plywood. The two inner joints can be attached permanently, but the ends that attach to the cabinets have to be detachable.

Questions:

1. What type of fastener would be best to join the panels to each other where a permanent connection is needed, keeping in mind that it 3/4 plywood joined end to end, the angles are slight, and no fasteners can be visible?

2. What type of fastener would be best to join the panels to the cabinets where a removable connection is needed, keeping in mind that it is 3/4 plywood joined end to face at a slight angle?

My though is that a cable management tray of some kind might be the solution to add more structural integrity and create more surface area, but I'm still not sure how it would all attach together. Hopefully someone has some clever fastener or joining trick that might work here.

Answer 1

What type of fastener would be best to join the panels to each other where a permanent connection is needed, keeping in mind that it 3/4 plywood joined end to end, the angles are slight, and no fasteners can be visible?

For this, I would consider a splined joint. The image below shows two boards that are coplanar, which is pretty easy to set up and execute. However, I'm assuming that if you can build a five-sided desk, you can jig this joint up with your 5-11 degree angle with little issue.

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What type of fastener would be best to join the panels to the cabinets where a removable connection is needed, keeping in mind that it is 3/4 plywood joined end to face at a slight angle?

Your afterthought here actually gave me an idea.

My though is that a cable management tray of some kind might be the solution to add more structural integrity and create more surface area, but I'm still not sure how it would all attach together.

I think adding something like a cleat to the inside of the modesty panel would be a good option. I imagine the inside of the modesty panel has a cleat glued to it with a matching cable tray piece that locks into place when it's assembled. Then you can attach the cable tray piece to the rest of the desk however you see fit. I would probably use pocket screws, but you have a better idea of your level of "fine-ness" required than I do. Maybe threaded inserts and bolts?

Note that this will require a bent or segmented cable tray piece to match the facets of the modesty panel. The image below shows a cut-through view of the modesty panel and the cleat.

Answer 2

What type of fastener would be best to join the panels to each other where a permanent connection is needed, keeping in mind that it 3/4 plywood joined end to end, the angles are slight, and no fasteners can be visible?

I Googled "blind hinges" and found some nice examples fromTectus and from ibmhCorp which could work nicely for the middle joints.

I am not suggesting either one, you can do a more thorough search to find what will work for you (skills and budget). The first above is quite pricey and the lower is inexpensive and looks to be kid stuff to install.

What type of fastener would be best to join the panels to the cabinets where a removable connection is needed, keeping in mind that it is 3/4 plywood joined end to face at a slight angle?

I then Googled "bed hardware" and found what could work nicely for the end connections from Woodcraft. Again, you can search for what will fulfill your exact needs, but this is a strong sturdy solution.

Normally, I would discourage anyone from making attachments with screws into the edge of plywood, but in both types of fastener, the major loading is not being carried by the screws, but by the flanges that are fit into the wood.

Answer 3

Rather than using a single thickness of 3/4" plywood for the skirt, I would suggest using two layers of plywood (they can be thinner if you like) with an internal wood frame not unlike a wood stud wall in a house. The overall thickness might be several inches thick. The top and bottom plates could be made from plywood shaped to the profile with internal 'studs' to support and mount the outer profile. If you use 1/4" plywood for the exterior panels you could also create a curved profile. for the skirt. Since the skirt now has some thickness you can secure the skirt to the pedestals using cleats and screws from inside the pedestal so that all connections are concealed. If you hold the top of the inside panel of the skirt below the height of the outside panel, you will have a simple cable tray.

Answer 4

Lamello has some interesting biscuits that may be of use as well, for example, their "Simplex" biscuits provide detachable edge joins (cutaway view):

There is also the "Clamex" series from their "P System" (although you do need their tools):

And their "Fast" biscuits (or just regular ones) plus glued edges provide permanent connections:

If you cut your edges to the appropriate 5/11/etc. degree angle you should have no problem cutting a biscuit slot (just make sure to not cut through the face depending on the thickness of your panels).