Help with first project - mid-century style wall shelving with baltic birch plywood

[Ken Cobbing]

Hi all,

I'm new to woodworking / cabinet building and have an idea I wanted to run past the old pros here. I'd appreciate critical feedback to identify any flaws with my idea.

I just hung up a wall full of Knape & Vogt (AKA John Sterling) "fast mount" wall shelving: 6' tall by 8' wide and 24" deep. These are great heavy-duty wall standards and brackets that hold a LOT of weight, don't break the bank, and made in USA.

After getting started on this minor "rough" project, I had the idea to make the shelves look like a finished piece of mid-century furniture by enclosing the shelves with sliding doors. The end goal is to make it look like a set of built-in floating shelves. For a rough idea, picture a wall of stacked cabinets like this (without legs of course):

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Or the sliding cabinets on the Eames storage units:

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Here is what the unfinished project looks like right now:

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My idea is to enclose the shelves with sliding doors by attaching a vertical piece to each side of the shelves to create a box. Then, cut a pair of grooves about 1/2" apart near the edge on each piece (top/bottom/sides) and insert 2 or more thin pieces of plywood to create sliding doors for each row of shelving. The structural integrity is provided by the wall standards and brackets. To keep the project as simple and inexpensive as possible, no additional hardware will be used for the sliding doors, but I have thought about adding UHMW tape to the door tracks to make the slide smoother.

Here is a photo of what the sliding doors would look like:

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So far I've only attached the wall standards and rough-cut the shelves to the correct depth (as shown above).

I have a few questions:

1) What thickness of Baltic birch panels should I use for the sliding doors? I suppose a minimum thickness is required to prevent bowing of the plywood doors. They will each be approximately 18" tall. I was thinking 1/4" (6mm) thick.

2) What width should I cut the grooves? For example, 6mm Baltic birch = 0.236". Should I make the groove fairly tight, like 0.25", or should I allow for some play to accommodate changes in thickness due to changes in humidity / temperature?

3) What method should I use to cut the grooves? I do not have a table saw. I have a track saw, Bosch palm router (Colt) and want to buy a plunge router (Bosch 1617EVSPK). If I use a router with a straight bit, will I have a problem with heat/burning when cutting a nearly 8' groove at a time?

4) I'm planning on attaching the sides with pocket screws. Any problems with that?

5) What should I use to finish the wood? I'm using 3/4" baltic birch. I'd like to keep as close as possible to the original light/white color and a very flat/matte finish. I'd also like the 13-ply eges to "pop" if possible. I was thinking of using Varathane "soft touch" matte polyurethane.

6) Related to the above question: do I have to finish the wood at all? These shelves will be used for long-term storage in the utility room and things should not move in/out too much, so wear on the shelves is not too much of a concern. The attached utility room is not conditioned and does get a bit hot / humid sometimes (occasionally a max of 85F / 60% for short periods of time), but never freezing (Florida).

Any help is appreciated. Thanks for reading!

[John Lankers]

Interesting project and lots of questions :-)
If that is a breaker panel behind your shelf it has to be accessible at all times and can not be covered.
If you're planning to purchase a plunge router you could easily cute the grooves with a 1/4" straight bit and edge guide, make the 1st pass shallow, no more than a 1/16" to prevent tearout. If the grooves are to tight repeat the cut once or twice without changing the settings on the router. I think 1/4" BB ply should work for the doors but 3/4" shelves without reinforcement might sag over time when the weight is to much - it's your call. I would definitely apply a Poly or Laquer. Nothing wrong with pocket screws for the sides but I would also add glue to the butt joints.

[Frederick Skelly]

Hi Ken, welcome to the Creek! Here are my thoughts. Understand that my answers reflect how I'd do it at my place and with my equipment - your mileage may vary......

1. I think 1/4" should be fine. I have a set that are 1/2", but you should be able to make it work with 1/4"

2. I'd make the grooves at least 5/16" wide. You won't get much seasonal change in the plywood. But you'll still want a bit of wiggle room.

3. Router with a straight bit and a fence/guide should work fine. Since you're new to using a router, don't try to cut the groove in one single deep pass. I'm concerned that, even with a fence on the router, you'll have trouble keeping the router in a straight line if you make a deep cut. Then your project will look crappy and the doors will bind. Instead, take multiple (shallow) passes getting a little deeper each time.

You might run a strip of blue painters tape down the line of the cut before the first pass - it can sometimes help reduce splintering. BE SURE TO PRACTICE MAKING THESE GROOVES ON SCRAP to get the hang of it before doing it on your project. Practice the full, eight foot cut and do both the top and bottom of the shelf to be sure you have the depth right. (Long story, below.)

Make the groove on top deep enough that you can lift the door high enough that it clears (comes out of) the bottom groove. At the same time, remember that you've got to leave room on the other side of the shelf to cut a groove for the next door. (Looking at most shelves on end, you will have 4 grooves along the same edge of the board - 2 on top and 2 on the bottom, directly above/below each other. Don't cut your grooves too deep or the shelf will break off at these grooves.)

Another idea is to stagger the door grooves. Make the top set of doors ride in grooves that are 1/2" from the edge. Make the one below it ride 1" from the end. Then alternate between 1/2" and 1" all the way down.

4. Pocket screws should work fine. Again, I suggest you practice making one or two of these joints on scrap before doing it on your project. I find that screws in plywood have to be done carefully or you can get a joint that's weaker than I'd like.

As John said, I'd also put glue on the joint before screwing it together. I've found that plywood butt joints that are glued and screwed hold together fine.

5. Varathane will work fine.

6. I'd put on at least one coat. I do it even with shop furniture and fixtures. It just keeps the dirt and fingerprints off of them.

Edit: Well, I just realized I've written you a reply that's even longer than your list of questions. Please forgive my long windedness. It just looked like you could use some help, especially with regards to cutting the grooves.

Good luck!
Fred

[Robert Engel]

Hi all,
1) What thickness of Baltic birch panels should I use for the sliding doors? I suppose a minimum thickness is required to prevent bowing of the plywood doors. They will each be approximately 18" tall. I was thinking 1/4" (6mm) thick.1/4" is fine. Cut the grooves about 1/16"wider. You won't get any appreciable changes with plywood to worry about.


3) What method should I use to cut the grooves? I do not have a table saw. I have a track saw, Bosch palm router (Colt) and want to buy a plunge router (Bosch 1617EVSPK). If I use a router with a straight bit, will I have a problem with heat/burning when cutting a nearly 8' groove at a time?I prefer spiral downcut bits for rabbetting. Passes 1/4" deep maximum, especially with hardwood. Make the top groove deeper to be able to lift the doors in.


4) I'm planning on attaching the sides with pocket screws. Any problems with that?In your application, I would use dados and screws with plugs. The sides will not be that noticeable. I am not a fan of pocket screws in plywood, but many use them successfully.


5) What should I use to finish the wood? I'm using 3/4" baltic birch. I'd like to keep as close as possible to the original light/white color and a very flat/matte finish. I'd also like the 13-ply eges to "pop" if possible. I was thinking of using Varathane "soft touch" matte polyurethane.Play around with a couple stains or stain/poly combos. IME BB does not stain well but does fairly well with shellac. I good choice for you would be polyacrylic. It is water based, and very forgiving in application.


6) Related to the above question: do I have to finish the wood at all? These shelves will be used for long-term storage in the utility room and things should not move in/out too much, so wear on the shelves is not too much of a concern. The attached utility room is not conditioned and does get a bit hot / humid sometimes (occasionally a max of 85F / 60% for short periods of time), but never freezing (Florida). No you don't.

[Brian Tymchak]

Hi Ken, Welcome to the Creek!

Interesting idea. A concern I have is when the shelves get a load on them, will the sliding doors bind due to shelf sag. Maybe you can run some tests to get comfortable what the shelves will do when loaded.

BTW, you do need to clear the electrical panel somehow.

[Ken Cobbing]

Thanks so much for all the thoughtful replies to my numerous questions!

@ Fred:

- Re: cutting the grooves: I have a track saw with a router attachment and could use that instead of an edge guide. I think that will be more foolproof for a beginner like me? I've also thought about making ~3 passes using the track saw to make the grooves. This would definitely be less exact, but would prevent any problems with overheating/burning/breaking the bit, and chipout. Is this a dumb idea?

- Good point on making sure that the top/bottom grooves don't get too close. I guess I wouldn't have thought about this until I was actually doing the cutting. Slightly staggering the top and bottom cuts' distance from the end is a great idea, and may actually enhance the mid-century look I'm going for.

@everyone:

- I should have mentioned this in my original post that the shelves have not been reduced from their 8' length yet, and the electrical panel will NOT be covered when this is finished. There will be a full 30" horizontal access as per code.

- Re: sagging: These shelves will mostly be used for lighter loads, but I would like them to be built more ruggedly than necessary. I used the "sagulator" which suggested that I should not have a problem with sagging using the 3/4" baltic birch plywood, but I'd love real-world feedback on this issue. The shelves are supported at 16" in the center and 32" at each end as shown in the photo. The supports themselves are rated at 300 lbs each, and I used rated GRK screws into studs.

- Re: vertical end piece attachments: I think the 2 vertical pieces on the end are mostly there for looks, with the additional advantage of keeping items from falling off the edges. Since these pieces are not structural (loads are borne by the wall brackets), I was thinking that a quick and simple pocket screw attachment would be good enough for the sides. An additional advantage to this method would be easy disassembly if necessary. However, John, Fred, and Robert all suggest stronger joinery (glue and/or dados). I must be missing something. Can anyone explain to me why something more complicated/stronger than pocket screws is preferable?

Thanks again for all the help. I'm trying to keep my questions to a minimum, but I'm starting from scratch and have a lot to learn!

[Frederick Skelly]

Ken,
Here's my thoughts on your questions. Again, your mileage may vary....

Cutting grooves with a track saw. I've never used a track saw, but the guys here speak highly of them. I'd try to cut practice grooves with the track saw using a piece of your 8' material. Cut all 4 grooves in the practice board and see if the operation feels safe and if it is working well. Problem is, you might have to run the router in the grooves to clean them up and flatten them. Otherwise, the doors may jam on the uneven bottom. If you find that happening on your practice part, I suggest you forego the track saw and just use the router plus your track saw track, in small passes as I described earlier.

Aside: Do not feel bad or foolish making practice runs. Many of us practice a new-to-us technique before actually using it on a project. I have built more than one complicated portion of a cabinet or other project to make darn sure I had the hang of it first. It let's you work out the kinks. You won't regret doing so.

Gluing the ends. Glue plus screws will just make it stronger. I'd do it just because it's easy to do, requires no more tools and it makes the joint better. You don't have to. But why wouldn't you, for the cost of a bottle of glue?

Keep us posted,
Fred