Woodworking Project: Bent Bookcases (Part 1)

A friend of ours did us a solid, and looked after our idiot cat while we were lying on a beach in Maui back in February, so as a small part of saying thanks, I offered to build her a bookcase for her living room and she eagerly (a little TOO eagerly) accepted and agreed to pay the material costs.

The only real guidelines I had were what the overall dimensions needed to be - she wanted a bookcase that would fit behind her couch, so 3 feet high and six feet long - and she would prefer, if at all possible, that the final design include some kind of curve.

Really, up until the curve part, this was sounding super easy, right?

I did what I usually do in these situations and turned to the Internet for inspiration. I found a few videos where people had successfully created curves in plywood (and other materials) using a technique called 'kerf cutting'. It's pretty simple, really: you just make a series of parallel cuts not quite all the way through the wood, and then you gently make it round. I ran a few tests and sure enough, it works just like you'd think:

The neatest part of this was figuring out that you can adjust the radius of the corner by increasing or decreasing the space between the cuts. (Turns out there's a calculator online that you can use to work it out, but it was way, way, WAY too mathy for me - I just made a bunch of test cuts. Okay, a LOT of test cuts.)

After playing around with a few ideas, I came up with a design consisting of two separate units, each more or less square, that could be placed next to each other, and with a curved top on the outside end of each one.

I know that sounds weird, so here's what they were supposed to look like when I was done:

Of course, the other advantage to this design would be if she decided to move them somewhere else, she could put the curved corners together instead of the squared ones, or separate them by a couple of feet and stick a plant in between, or even just have matching bookcases on the opposite sides of a room (or doorway, which I think would be seriously cool).

The design called for pretty standard construction - plywood carcasses, hardwood edge banding, dadoes for the bottom shelf, and adjustable middle shelves. The real challenge here was going to be that curve, and how to conceal the plywood edge on the other top corner joint. Usually, you'd be able to add a little extra edge banding here and there to cover it up (like the other bookcases I made way back when), but because I wanted to keep the edges clean and a uniform thickness, I wouldn't have that luxury. I eventually decided on a miter joint which, even though isn't the strongest in the world, would allow me to use splines, which are my favorite things.

Then it was off to Windsor Plywood to pick up materials, and where I made the first (and most costly) of several mistakes in this project. They had some beautiful sapele on sale, which was perfect for the edge banding, and some really cheap "Baltic birch" plywood  - only $40 for a 4x8 sheet! I bought what I thought I would need and brought it all home to start roughing out the cases.

Oh, but first, I made a jig! (I got to make SO MANY jigs for this project. It was awesome.) Possibly the largest jig I've ever made, and it worked (eventually) like a hot damn. Of course, moving it around the garage every day for six months sucked, but hey.

I cut all the plywood down to rough size for the various shelves and whatnot, and grabbed an offcut to test the saw set up before making the kerf cuts for the bent corners. Which is when the truth of that old adage was brought home in all its truthiness: you get what you pay for. That plywood was absolute garbage. Just trash. It didn't bend so much as just explode in my hands.

On closer inspection, yeah, I probably should have known. Look how thin that top layer of veneer is, compared to decent (actual) Baltic birch:

Needless to say, it was back up to Windsor plywood for a couple new 4x8 sheets of proper birch and a little more sapele as I'd underestimated the requirements just a little (as usual). Suffice to say that the new stuff was a bit (3 times) more expensive, but so, so, so much better quality.

After cutting down all of the new plywood into appropriate finished sizes, I began conducting some glue tests. The good news was that the actual Baltic birch worked like a dream, and I was able to refine my cuts and create the first real mockup:

The bad news was that the glue I was planning on using was not so good. See, I was going to use Gorilla glue which, being a polyurethane glue, expands much like insulating foam to fill any gaps in your joints. The problem is that once expanded, Gorilla glue has absolutely no holding power at all. The expansion really only works to fill minor flaws - not when trying to fill in a gap of a good 1/8th of an inch. The even worse news was that while Titebond III, my old standby, was certainly better, it wasn't a whole lot better.

I started to get a little bit worried about my design at this point, to be honest. I knew that, sooner or later, at some point someone was going to try and shift one of the bookcases slightly or try to move it outright and it was probably going to be full of books at the time. With a miter joint at one end and a curve that relied on removing a whole lot of material at the other, if that someone happened to pick it up by the top, the entire thing was likely to tear apart. If I was going to have any structural stability in the tops of these things at all, I was going to have to revise my design.

So I came up with a two-fold solution: first, I was going to glue in the top shelf using dado joints, just like the bottom shelf, leaving only the middle shelf adjustable. This would provide some rigidity and stability right near the top, where it was most important. Second, I would have to come up with some type of spline arrangement within the bent corner as well. I wasn't entirely sure how that was going to work, obviously:

But I felt pretty confident I could figure something out. In the meantime, it was on to the dado-ing!

I spent WAY too much time faffing about with a couple different designs of router-based dado jigs before throwing them all in the trash and going back to old reliable: chucking the dado stack in the table saw.

And even though the length of the boards was a little tricky, it worked!

Then I got to use one of my fiddliest jigs, the shelf pin drilling template:

After that, I couldn't really put it off any longer. It was time to stop making test cuts, and just bend the damn wood already:

Much to my delight and amazement, the jig worked perfectly. The bend happened in exactly the right spot, the kerfs closed tight without splintering, and the pieces even came out square. I managed to sort of impress myself, actually.

After they dried up, it was a relatively simple matter to (carefully!) cut them to length and miter the end at the same time. Considering how many things had to go exactly right for them to line up this way, I was absolutely ecstatic at how they turned out. They were virtually identical:

I did put in some biscuits in the miter joint for added strength, and cut a couple of really interesting gouges in my work top at the same time, just as an extra reminder of why I need to not get cocky.

Spoiler alert: this was not the last time I got this reminder during this project. But this blog post is getting too long already and starting to bog down the editor with all the pictures.

But fear not - Part 2 is right here.

Adventures in wood bending

My original title for this post was "How NOT to build a steam box". Still not sure I went with the right one, but whevs, as the kids are saying. (I think it needs more ... spelling. Like, maybe "whyevfs". Or maybe less? "wfs"? Meh.)

Anyway, I'm currently working on some bookcases for a friend, and like EVERY project, I just had to go and make them complicated. The "client" needed a bookcase to go behind her couch, and really wanted a curve involved somehow. And, long story short, I needed to come up with a way to bend the edge banding to go on the faces (and backs) of the case.

I'll have a post about the project as a whole when I'm done, but wanted to vent (ha! Vent! Get it? Oh, no, wait. I should have saved that pun for the end. Sorry.) about this particular part. Mostly because I've been posting pictures to Facebook and there are a LOT of very confused people out there.

So the concept of bending wood is pretty straightforward: put the wood you want to bend in some kind of container, fill the container with nice hot steam, and wait for a couple hours or so. Then you take the wood out, clamp it in the shape you want it to stay and let it dry. Presto bendo!

I watched a couple of YouTube videos and took note of the ones that seemed to work, and then set out to bend some wood.

My first challenge was to come up with some kind of heat source. Fortunately, our barbecue has a side burner (which we've used exactly twice). If I could set up a steam box in the back yard, I could boil a big ass pot of water on the barbecue and wouldn't have to worry about running out fuel, thanks to the natural gas line.

The next part was to come up with a steam box. I saw quite a few people build theirs out of plywood, but I watched one enterprising fellow build his out of a length of heavy plastic pipe. I figured that was faster and slightly cheaper than the plywood option, and hied off to the plumbing supply store. I got a 10' length of heavy-duty PVC drainage pipe (I cut a couple feet off just to make it slightly less unwieldy) and a couple of end caps to help seal the steam inside. I drilled pairs of holes every eight inches or so, just slightly below center, and ran dowels through to give me something to rest the wood on. I even grabbed a cheap temperature gauge and attached it near the venting end of the pipe so I could have an idea of the temperature inside the pipe without having to open the cap all the time. (And I remembered to drill some drain holes at the low points to make sure the condensation build-up had a way to get out, and that the pipe wouldn't get too pressurized. Yes, I was that deluded - pressure! Ha!)

With that taken care of, I needed to find a vessel in which to boil the water for to be making with the steam hot. Finding a steel bucket proved to be a lot harder than I thought it would be, but my Crazy Neighbour came through as he usually does, and found a metal bucket that wasn't rusted too badly. I fashioned a top for the bucket out of a piece of plywood and some little c-clamps, and figured that would hold well enough for a proof of concept.

It's worth pointing out that I was still labouring under the impression that all of this was going to work on the first try. Faithful readers, you already know I was wrong.

So I had a heat source, a vessel, and a steam chamber. The next problem was getting the steam from the bucket into the pipe. After casting around a bit and checking out the usual suspects, I found a deal on a replacement shop vac hose. I figured it was probably a little bit long, but my main YouTube inspiration (he of the plastic pipe steam chamber) had a great jeezly long feed pipe and his set-up seemed to work out just fine.

I attached one end of the shop vac hose to the plywood bucket lid, ran the other end in through the end cap of the PVC pipe, and threw together a couple of quick stand-offs to support the pipe on the sawhorses beside the barbecue. And I had myself a steam box!

It took a little while, but the water in the bucket eventually started boiling, and steam began making its way into the shop vac hose which, catastrophically weakened by the boiling hot vapour inside, promptly collapsed upon itself and started to melt.

Back to the drawing board!

(The good news is that the shop vac hose is the same size as the one on our shop vac and, after a minimum of careful trimming, we now have a back up hose should ours ever get run over by the car. Again. But that's another story.)

For take two, I abandoned the frailty of the plastic shop vac hose and went to something that was a little more purpose-built for moving hot air: dryer vent!

A quick re-jiggering of the bucket lid and a little hollowing out of the end cap, and Take Two was up and running later that day.

Man, that dryer vent got hot! Whew!

Unfortunately, the inside of the PVC pipe did not. Time to reconsider.

I did a little more research and thinking, and came to the conclusion that the steam just wasn't getting into the pipe fast enough. The dryer vent was so big, and so poorly insulated, that the steam was cooling off about halfway through, and nothing of any significant temperature was reaching the chamber.

I decided I needed two things: a narrower gauge transfer pipe between the bucket and the steam chamber, and a way to get the steam into the transfer pipe faster. It took some online shopping and perseverance (and mutilation of the most beautiful gas can I'd ever seen), but I managed to accomplish both.

The gas can works better because the steam has nowhere to go except through the narrow opening. With a vigorous enough boil, the steam is forced into the transfer pipe (a piece of flexible exhaust pipe for a motorcycle) quite quickly. I also moved the entry point for the steam into the middle of the steam chamber so that both ends would heat evenly, and the heat would be concentrated in the center of the wood, which is where I needed it to bend.

Yep, all in all, a much better set up than my first two attempts. In the end, it wasn't any more successful, though. The side burner on the barbecue just wasn't powerful enough to get the water really boiling. It only reached a gentle simmer, not the high rolling boil that I needed. No boil, no steam:

I was pretty much at the end of my rope at this point, and ready to just cut the bends out of a plank on the bandsaw, but I was convinced to give it one more go. Mostly because we're going to have to do some wood bending if we're going to restore our canoe, but partly because I wasn't going down without a fight on this one.

So I ordered a turkey fryer propane burner and reassembled the entire monstrosity in the front driveway.

(The neighbours were.... well, "intrigued" might be under-selling it. Let's go with "concerned".)

But damn me! It worked! We got steam!

The set up required some further tinkering, of course. After about 45 minutes or so, the transfer pipe started making a weird kind of chuffing noise. I poked around a bit, and figured out that the lower bend was full of condensate. I drilled a small hole right at the low point and once it finished draining, the noise stopped and full steam resumed.

Oh, hey! I bet you didn't know that PVC pipe will start to lose structural integrity right about 250 degrees F!

Yeah, I was getting some serious droopage. I hauled out a few extra sawhorses and roller stands to shore it up as best I could, but I was starting to think that I wasn't going to get a second shot at it out of this particular rig.

But I had a pipe full of steam, the wood was getting nice and toasty and I was going to give it a serious go. I set up my bending jig in the workshop and made sure I had a clear path between it and the steam chamber.

After almost two hours, I decided I'd see if the wood was at least close to bending. It was not.

I probably could have left it in longer, but really, I wasn't getting that curve out of it without the wood being 90% moisture, and I was worried I was going to run out of propane as it was. I had probably also failed to plan for how much the wood was going to twist as I was bending it. I would have had to have kept it in the jig for hours and I only had one jig - and four pieces that needed bending.

So, yeah. After all that, I had nothing to show for it except a badly misshapen length of PVC pipe and some slightly damp pieces of sapele.

The next time, I'm just making the box out of plywood, damn it.

A total frame job

Anybody says anything about how long it's been since I posted here, and I'll shut it down for good.

So, I might have mentioned this before, but my old man's a hell of a photographer. (Check it out: http://photographybywm.com/index.html No, seriously, check it out. I'll wait.) The last time I went up to visit, he was putting on a bit of a show to celebrate the release of a calendar he produced that focuses on the inimitable women in his little town. I helped him out with a couple of minor things, and in return, he gave me a photograph. An amazing one.

Well, I couldn't just tack it up on the wall, and I was in need of a little shop time after spending way too much time at my desk, so I took a day off and hied myself out to the garage one fine spring Friday.

It went something like this...

First, get big stick:

(In this case, the stick was western red cedar - a little piece left over from making the closet doors for my neighbours.)

Next, make stick flat:

Realize how long it's been since you did any basic saw maintenance and spend a gloriously happy 30 minutes making everything clean and shiny and not squeaky:

 

Turn stick into smaller sticks:

 Choices, choices:

When it doubt, go BIG:

I swear I JUST cleaned that:

That's a good start to a profile:

Profile's done, gotta cut the rabbet:

Sandy Sanding McSanderson

Gotta build at least one jig:

Splines! (And four coats or so of finish.)

Hopefully a frame worthy of the picture it was made to hold (and hanging in the front hall):

 Thanks Dad! We love it!

Woodworking project: CD cabinet ... drawer ... rack ... thing

This thing.... this thing was one of those projects, if you know what I mean.

And if you don't, well, I'll try to explain. (I make no apologies for the length of this post. Get comfy.)

This started, as most things do, with a complaint from the War Department. (This is patently false, by the way. None of this is her fault at all. Except the part where she encouraged and suppported me.  But it makes a better narrative in my head if I can blame it all on her, so let's just go with that.) She has a really good Bose stereo that sits on the counter in the kitchen, and we use it all the time - especially when we're cooking or entertaining, and even if we're just hanging out in the family room. It's got amazing sound and a nice little remote (and it hardly ever skips at all now that we got the moths cleaned out of it), but it only takes one CD at a time.

We also have a perfectly cromulent CD rack that I "inherited" a long time ago from a friend who was moving and didn't need it anymore. It's a free-standing floor unit with enough room for pretty much every CD we own, but there's nowhere near enough space for it anywhere near the kitchen, so it hangs out at the far end of the room - exactly as far from the stereo as it can get. This meant, of course, that there was always a big stack or three of loose CDs teetering precariously on the edge of the counter or on top of the "junk drawers". It was really starting to get on our nerves, and it was hard to find a particular CD. (We really did need a better solution, but it's still Amy's fault for pointing it out first.)

After a lot of thought and futzing about (months, actually), I drew up a model of what I had in mind in SketchUp, and even built a full-scale mock-up of the drawer "mechanism". There were a couple of minor details that I didn't have worked out entirely yet, but I figured I had enough of a plan that I could get started.

Which, as usual, was where things started to go wrong.

See, I had an idea in my head of how this thing was going to work, and I was convinced that it WOULD work. Unfortunately, it was kind of my own stubborn devotion to this imagined design that made the project more difficult than it really needed to be. (Hey, stop me if you've heard this story before.) I probably could have just nailed a few boards together and piled the CDs on top; as long as they were out of the way, we'd be happy. But I just had to make it challenging... (Though, to be fair, we did look at a fair number of CD racks and whatnot online and didn't like any of them.)

The first problem arose when I went digging around in my copious piles of scrap and offcuts, looking for the wood to build it with. Sadly, this was before I got my new woodshed (have I posted about that yet? No? I should do that soon...) and I didn't really have the material I wanted/needed to implement my design. I wasn't even really sure what wood I wanted to use, I just knew that if I was going to make something that looked really nice, I wanted to use some decent wood - not just whatever scraps I had on hand. Finally, after solving some design issues I'll cover in a minute, I went up to the store and paid way too much money for some 3/4" edge-grain fir. 

A quick note about my final design (you could put every single word in that clause in quotation marks to denote ironic usage, and you'd be right): I had worked out a design that looked a bit like a horizontal version of my Scotch cabinet - one of the reasons I went with fir, in fact. But instead of doors, it would have two drawers that tilted outward to show the spines of the CDs. I found an old Fine Woodworking article online that showed a similar style of drawer to what I had in mind, and co-opted the design for my own use. I did have one problem with their design, which is why I built the protoype of the drawer, and it's a good thing I did because I was actually right, and the drawers might not have worked at all had I just followed their layout.

Actually, you know what? I'm kind of proud of myself for figuring this out, so I'm going to explain what it was that I did. Or try to anyway.

Here's what their design for a tilting drawer looked like:

There's a rounded groove cut in each shelf, and a matching rounded lip or bead on the bottom of the front of the drawer that rests in the channel. This allows the drawer to tilt forward while resting in the channel. The issue I spotted with their design was that the pivot bead is at the back of the drawer front. When the drawer tilts forward, the front of the drawer acts as a lever, lifting the bead out of the channel - you can kind of even see it happening in the cutaway diagram on the right.

This didn't make any sense to me - the channel and bead should be on the front edge of the drawer. That way, when the drawer tilts forward, the bead pivots in the channel and maintains contact throughout the opening process. And what do you know? When I built my mock-up, I was right! (I also figured out that it would work a lot better if the groove was cut closer to the front of the shelf.)

Of course, I also needed to alter the original drawer from the article in a rather more substantial way: it needed to be a fair bit deeper to accommodate the height of a CD case. As I quickly figured out, however, the deeper the drawer, the bigger the radius, and the taller the front of the drawer would have to be. I spend a lot of time fiddling with my prototype, making two-dimensional mockups, and double-checking the results in SketchUp. In the end, instead of an 8-inch drawer front, I needed something that was a lot closer to 9-and-a-half. But the material costs for 10" boards was astronomical - no way I wanted to spend that much money on a design that I wasn't even sure was going to work!

Then I thought I'd take another cue from the Scotch cabinet and make simple frame and panel "doors" to use as drawer fronts, but that presented a couple of problems: first, all of the material was going to be 5/8 thick, which would make for some very small, and therefore very weak, tenons. Second, a standard frame-and-panel construction would not leave a flat surface on the back of the drawer front for the CDs to rest against.

My solution was to create a wide, flat drawer front that looked like it was frame-and-panel, but used half-laps to create stronger glue joints and a flat surface on the back. I also left a slight reveal between the pieces on the front as a little design detail.

Of course, gluing these panels together required a very specialized glue-up jig:

And a few miscellaneous pieces of heavy stuff to keep it all flat while the glue dried:

But damn it, it worked! Back of the drawer front on the right, front of the drawer front on the left:

The carcass was fairly straightforward - just some stopped dadoes for the top and bottom, a through-dado for the sides, and a lot of double-checking that the channels for the pivot beads were facing the right way. Of course, I actually messed up this step - I didn't do a very good job of squaring it up during the glue up - and I paid for that later when it came tip to fit the drawers:

After a fait bit of swearing and a lot of sanding, I managed to get the drawers fitted in the case, and actually opening as intended:

Which brought me to my next design challenge! I needed a way to keep the drawer from falling forward out of the case when it was opened. Also, for some reason, I always felt that the drawers should be removeable. In retrospect, I'm not sure why.

The article I was using as a starting place had a simple enough suggestion: a wooden stop, mounted on the shelf above the drawer. The stop would fit through a slot in the rear of the drawer, and then pivot to lay across the slot once the drawer was in place. If you needed to remove the drawer again, simply rotate the stop so it fit through the slot, and the drawer would lift (or fall) right out.

This system was easy to set up and worked like a charm... except that it kept the drawer from opening all the way. No matter the thickeness of the stop - even if I used a simple pin, it meant that the leading edge of the back of the drawer couldn't go any farther forward than the rear edge of the front of the drawer. (I wish I'd taken a picture, because I know that's confusing to explain, but I was so frustrated by this oversight that I just forgot.) I did take a picture of the repair I had to make to the drawer after I realized it wasn't going to work:

What this meant for my purposes is that it kept me from being able to slide the CDs straight out of the drawer - I had to tilt them to get them out. Obviously, this wouldn't work if the drawer was anywhere close to full.

This became one of those moments where I vacillated between chucking the whole thing in the fireplace and starting over, and frantically scribbling down possible solutions. Eventually I settled on a system where brass pins, inserted through the sides of the case, would ride in grooves along the sides of the drawers. This meant performing a little router surgery on the already-assembled drawers, AND drilling holes through my beautiful case, but it turned out all right in the end. Mostly. (I supposed that it's still theoretically possible to remove the drawers, but I wouldn't advise it.)

After all the fiddly bits of drilling and checking and sanding and bluffing in the drawers and cutting brass rods and whatnot, it was finally time to apply some finish. For that, I went with the old favorites approach of a coat of Danish oil and two coats of poly:

That's actually not a bad shot of the grooves that I had to rout in the sides of the drawers and the holes in the carcass for the brass pinss - well, sort of. Nothing's quite facing in the right direction, but whatever.

Oh, and I was originally going to put a back on it, but decided it was really just more weight that the  project didn't need, so I added a French cleat for wall mounting and left the back open.

And then I hung it on the wall right next to the stereo (and directly below the Scotch cabinet). Admittedly, it's a temporary location and not ideal (the damn thing turned out a little bigger than what I originally had in mind) but it works!

Except.... yeah. I don't know if you've noticed (I didn't until after I'd already installed it), but there's a rather huge flaw in the overall design. A bad one.

You see, in my eagerness to make a cabinet that could hang on the wall or sit on the countertop, I had changed the structure so that the long sides (the ones with the horns) were on the top and bottom instead of on the sides. Unfortunately, this meant that the dadoes were now vertical instead of horizontal.

The entire weight of the cabinet (and all of the CDs inside) hangs from the two dadoes in the top shelf. And the bottom shelf is hanging from the sides while supporting the weight of the bottom drawer. (The middle shelf is the only one with decent structure as the dadoes fit into the sides of the case, providing material support underneath the joint. Though it's all still just hanging from the top shelf,...) As if that wasn't bad enough, the drawers aren't exactly soft-close. If you're not really gentle when closing the drawer, you're basically smacking the shelf with a large, heavy hammer.

Despite this, we left the cabinet in service for a few months and it was working okay. That is, until I showed it to a friend of mine with some experience in making fine furniture. (Ironically enough, the same friend that gave me the CD rack we're not really using anymore! How's that for parsimony?!) I didn't even need to point out the flaw to him because he spotted it right away. That was really all the confirmation I needed - time to finally do something about it.

I took the cabinet off the shelf, added some nice long screws to each of my dadoes in the top and bottom, and cut some plugs to fill in the holes:

Heh, you can tell from that last shot that I had the "foresight" to use screws and plugs when attaching the French cleat to the back of the case - the one joint that really didn't need them!

Anyway, this also required sanding off the finish on the top and bottom, but it was easy enough to reapply, and I felt a whole lot better about filling it with 30 pounds worth of music afterwards.

So, it's done!  Thanks for reading this far, and allowing me to vent a little. Despite all my complaining, it was actually a fun thing to build. Though I'm not 100% happy with how it turned out, I'm pretty proud of myself for coming up with the solutions to some of the problems I faced. Like so many other projects, it would be a lot easier to build the second time... like anyone anywhere would ever need a cabinet like this for anything.

And, hey: with a little luck, I can use the lessons I learned to avoid making the same kind of design and build mistakes with my next project. Yeah, right. I can always find new and exciting ways to screw it up. Stay tuned!