Living with the flaws, and what to build next
Okay. Shelf's on the wall. It's level, or level enough, and it's holding weight, and you built it. That's the whole class right there, done.
So now what.
Look at it honestly
Go stand in front of your shelf for a minute. Not right after you hung it, when you're just relieved it's up. A day or two later, when the adrenaline's worn off.
You're going to see things. A gap at one joint that's a little wider than the others. A spot where the sanding didn't quite get the swirl marks out. Maybe a screw head that's slightly proud of the surface because the wood was harder than you expected right there. I promise you it's there, because it's always there. Nobody's first shelf is clean.
Here's the thing. That's not a failure report. That's just what a first build looks like, and it's worth deciding right now how you're going to feel about it, because you're going to be looking at this thing for years.
My first shelf was cut a quarter inch too short on one side. I measured from the wrong end of the tape, which is exactly the kind of mistake I now spend half a class trying to keep people from making, measure from the same reference edge every time, don't jump around, because your errors stack up on you if you don't. I didn't catch it until it was already up on the wall, sagging just slightly on the short side. I hung it anyway. Not great, but it held. It stayed there for four years before my wife Mary finally asked why one edge dipped a little. Four years. Nobody else ever noticed. I noticed every single day, and it didn't stop me from using that shelf for four years of family history boxes.
So that's my answer for what to do with the flaw. Mostly, live with it. Let it be the thing that tells you which shelf was the first one.
When it's actually a problem, versus when it's just a mark
There's a difference between cosmetic and structural, and it's worth being honest with yourself about which one you're looking at.
Cosmetic: a rough patch, a slightly visible glue line, an uneven stain color, a screw that's not perfectly countersunk. Live with those. Sand them down more if it bugs you, but don't take the thing apart over it.
Structural: a joint that flexes when you push on it, a wobble that wasn't there right after clamping, a crack that's actually growing. If you push on a corner and you feel movement, that's not a look-at-it-later problem. Take the weight off it, figure out which joint is moving, and either reglue and reclamp or get someone to look at it with you before you load it up with your grandmother's photo albums. A shelf that fails is a mess and possibly a mess on your foot. Don't be precious about pulling it back down if something's actually wrong.
For everybody else, most of what you're seeing is cosmetic. Let it be.
What to build next
I get asked this a lot at the end of a session, what do I build after the shelf, and I'd rather answer it honestly than give you some big exciting list.
Build another shelf. I'm serious. Same design, or close to it, in a different size, for a different wall. The reason isn't that it's more useful, though it probably is. The reason is that everything that felt hard this time, the marking, the glue-up, the square check, the sanding you didn't want to do, all of that gets a little more automatic the second time. You'll notice yourself not needing to think about the reference edge. That's the whole game, building the same basic moves enough times that your hands know them before your brain has to work it out.
After that, a small box is a nice next step. Same joints, same square-checking, smaller and a little more forgiving because there's less wood to fight with. Sanding a box is a good teacher too, I dropped one on my garage floor once after a whole Saturday of sanding, chipped the corner, filled it and sanded it again and ended up liking it better with the story still in it. That's sort of the whole lesson of this last class, honestly. The story stays in the wood whether you want it to or not.
A step stool is good too, if you need one. Just measure the actual height you need twice as carefully as you think you have to, that's a different lesson for a different day.
Before next time
No homework, really. Just live with your shelf for a week before you decide what you think of it. The flaws you notice on day one usually aren't the ones you'll still be seeing on day thirty.