The Lawnmower Method

Time passes...

2009-02-24T22:42:00.003-05:00

Well, it looks like there's a huge gap in my crib-making documentation. The following steps don't have pictures, so you'll have to be content with just seeing the finished product at the end.

First I cut a groove 1/4" wide and 1/2" deep along the inside edges of the rails and styles. This groove holds the maple panel in place. Next I cut the maple panels to size. As with the mortises, this cut is complicated by the fact that the top tail is curved. Finally, I cut a rabbet along all the edges of each panel: the idea is to leave a 1/4" thick lip that slides into the grooves in the frame. This technique is standard frame-and-panel assembly.

Next I designed decorative cut-outs for the panels. On one side I have a night-time scene: moon and stars. On the other side I have a day-time scene: sun and reeds. The only neat-o aspect of the cut-outs is that the star pattern matches the constellation Scorpius, which is Jonah's zodiac sign. Cut-outs are easy to design, but not so easy to cut out. I used a combination of the power drill, saber saw, and hand tools. Cleaning up the results required lots of hand chiseling.

Finally, I glued the parts of each side together. Note that the only glued parts are the rails and styles of the frame. The panel is not glued -- it "floats" in the groove, allowing seasonal expansion and contraction of the wood. All in all, I think the sides came out great. Note, however, the very serious face of the "customer".

Side frame joinery

2009-02-24T22:25:00.002-05:00

Each crib side consists of a cherry frame with two maple panels (see previous posts). In this step I made mortise and tenon joints for the frame. The tricky part is that the frame is not entirely square: the top rail is curved. As a result, the mortises go into the top tail at funny angles -- funny angles that need to line up perfectly, or the frame won't fit together correctly!

In the first two pictures you're seeing the three styles (vertical parts of the panel) each with a tenon that fits into a mortise in the bottom rail. This part was fairly straight forward because the styles go into the bottom rail at a right angle. I used the tenoning jig on the tablesaw to cut the tenons, the mortising machine to cut the mortises.

Making the joints for the top rail is much more tricky. My strategy is to extend the lines of each style up over the top rail so that I can see what the angle of the mortise needs to be. Then I use a crazy set up on the mortise machine (not shown because it was too crazy) that holds the top rail at just the right angle. Finally, I have to cut the shoulder of the tenon so that it matches the curve of the rail. What a royal pain! But the results are pretty good.

The last picture shows the resulting frame dry-fitted together. The panels are just lying on the bench behind the frame. I still have several steps left: (1) cut a groove in the inside of the frame to hold the panel, (2) cut the panel to size, (3) cut a lip (a rabbet) on the edge of the panel so it fits in the groove.

Panels

2009-02-24T22:13:00.003-05:00

Well, it's been a while since I added anything to this blog -- you can probably guess why! That's not to say that I haven't been working on the crib, bit by bit. Now I want to get you caught up on where I am...

The next step was to make the maple panels for the sides. In the previous entry I had resawn a large board into thinner and smaller boards. Next I edge-glued groups of boards together to form the four panels I need -- two for each side. The clamping set-up for gluing a panel is fairly elaborate: I have pipe clamps holding the boards together, and the clamping cauls holding the boards flat and aligned.

Side order

2008-10-22T22:05:00.005-04:00

I finally got back in the shop last weekend and made some real progress. The front, back, and legs are basically done, so now I'm focused on the sides. Each side will consist of a cherry frame with solid maple panels. Both the top and bottom are curved, so the joints are tricky; plus, the side must fit perfectly between the front and back, which are also curved.

I started out making a template for the top rail, which curves from the back leg down to the front leg. My idea was to set up the legs on a piece of construction paper and draw in the shape I want. I cut out the paper and used it as a template to cut the rails (two of them; one left and one right). The trickiest part is that the ends of these rails need to be curved to fit the curves of the legs.

Next I cut the bottom rail, which is simpler because at least one edge is straight. Finally, I cut three styles for each side panel -- a left, right, and middle. The next step will be to cut mortise and tenon joints to assemble the frame. Again, the tricky part is that the top joints are not square (more details to come soon!)

Before cutting the frame joints, though, I decided to make the maple panels. Each panel will be about 12 inches wide, 27 inches tall, and 1/2 inch thick. These specs present two problems. First, my jointer is only 6 inches wide, so I can't joint a single 12 inch board. Second, 1/2 inch thick stock is not readily available.

The next six photos show the process of making these panels. I started with a single large 10 inch wide 6/4 maple board, which I cut into six equal size boards. Each little board is about 5 inches wide, so they will fit on the jointer. Then I resawed each board (sliced the board) using the band saw to produce two 3/4 inch thick rough boards. Finally, I rejointed and thickness planed each board down to 1/2 inch. I now have 12 boards, each one is 5 inches wide, 27 inches long, 1/2 inch thick.

These last two pictures show the parts of the side panel assembled roughly as I'm hoping them to look. Once I cut the joints for the frame, I'll cut a groove along the inside edge of the rails and styles to hold the maple panels. Eventually, I'll cut a moon and stars in the panels.

On the Rails

2008-09-20T23:27:00.006-04:00

The last couple of days in the shop I focused on the top rails of the front and back. In the previous post you can see that each rail is a slab of cherry 6" wide and about 1 1/2" thick. In the design these rails curve forward and backward to match the curve of the legs. The rails are then attached to the slat assemblies.

Shaping the rails involved several steps. First, I made a 12 degree cut on the edge of each rail so that when butted against the slat assembly the sit at the proper angle. At this point, though, the faces are still flat. Next I made two very shallow angled cuts on the face of each board that roughly follow the intended curve. Then I used a combination of planing and sanding to finish the curve.

Attaching the rail to the slat assembly presents a challenge. The joint needs to be strong, but it's difficult to clamp because of the angle. My solution is to use a spline. First I cut a 3/8" groove in the mating edges of both parts. I then cut a strip of hard maple (the spline) to join the two pieces. The spline not only strengthens the joint, it also helps keep the parts aligned during clamping.

Here are a few pictures of the front with the legs -- it's really starting to look like a bed! Tomorrow I'll glue the rails and finish shaping the legs.

New Posts

2008-09-13T22:47:00.004-04:00

It's been a couple of weeks since my last post, but I have been working on the crib. In fact, I made the posts!

Each post starts out as a slab of cherry 4 inches wide and about 2 inches thick (a "blank"). In order to make sure that the front and back fit I decided to lay out the shape of the post with the other parts in place. In the first three photos you can see that I clamped the front and top rail where they should be on the post blank. Notice that the top rail will be curved, so I'm positioning it in the outline of that curve on the post blank.

Using the position of the front parts as a guide I made a template for the curve of the foot. I copied that onto all four posts, using a slightly shorter version for the tops of the posts. I cut along those lines on the bandsaw.

After look at the results I felt like the posts were a little boring, so I decided to add a secondary curve on the inside of the foot. This cut can be a problem on the bandsaw because the foot is no longer properly supported. I learned a nice trick to solve this problem in a woodworking class: tape the cutoffs from the first curve back onto the piece, making it look like a whole blank again. Then make the secondary cut. Tomorrow I'll post pictures of the finished legs. Needless to say it takes a lot of scraping and sanding to get the resulting curves smooth.

Glimmers

2008-08-28T17:44:00.005-04:00

Last weekend was a mixed bag. On the one hand I struggled to get two more good-quality coats of lacquer on the slats. On the other hand I finally glued the slats into the top and bottom rails -- the first assembled (and recognizable!) parts of the crib.

Saturday was a warm humid day, and as the sun beat down the water-based spray lacquer became more and more temperamental. I sprayed a couple of fairly ugly coats that dried too fast. I had to sand them smooth, which was a huge pain (see photo of lots of wet/dry sandpaper). I finally got a nice finish coat, which I sanded one more time with 800 grit wet/dry sandpaper, and polished with super-fine steel wool. The surface is silky smooth.

The glue-up was a little tricky, since it involves putting glue on 14 mortise and tenon joints and then getting the whole thing lined up before the glue starts to set. It went remarkably smoothly and I was able to set the clamps in plenty of time.

Here are the resulting front and back panels of the crib -- note that the cherry is not finished yet, so it looks pale and somewhat cool next to the maple. Once the rest of the crib is done I'll finish the cherry with shellac and probably a coat or two of water-based varnish for durability.

Notice that the bottom rail of the front is curved. I cut this curve after cutting and fitting all the joints, but before gluing. This is all fine and well, except that the curve makes it very hard to clamp the assembly. One neat trick I learned is to save the cut-off piece from the curve cut and use it as a brace for the clamps. It fits perfectly and squares up the bottom rail. The next step will be to shape and attach the decorative top rails that curve forward and backward to give the "sleigh" shape.

Finish before you start

2008-08-16T21:52:00.006-04:00

Every now and again I manage to learn from a previous mistake and do it right the next time. In this case I realized that it would be much easier to pre-finish the slats than to finish them after assembly. I also realized that I might want to use different finishes for the slats, since they're maple and the rest is cherry. I decided to spray them with water-based lacquer -- Target Coatings makes a fantastic product called USL. Water-based finishes are nice because they clean up easily, are non-toxic, and safe to spray without crazy equipment (like "explosion-proof exhaust fans".)

In order to make spraying easy I came up with this set-up: the slats are held in a frame made of scrap wood. I can easily spray them all at the same time, but then disassemble it to sand between coats. In addition, the scrap pieces cover the tenons so that they don't get finish on them.

I started out with a thinned-out coat to seal the wood and penetrate for better "popping" of the grain. I also added a tiny bit of aniline dye stain (from J.E. Moser's) directly to the finish to compensate for a common problem with water-based finished -- unlike solvent-based finishes, they impart no yellow color and can make wood look cold.

I sprayed a total of four coats of USL using my HVLP (high-volume, low-pressure) spray system. I bought a 3-turbine machine several years ago from American Turbine -- it was pretty expensive considering that it's basically a glorified vacuum cleaner with a hose and a spray gun attached. The lacquer goes on easily and dries fast.

All in all I'm pretty happy with the results. Look at that grain! I'll probably sand them again and add two more coats tomorrow -- just because.

Shaping the slats

2008-08-09T08:48:00.005-04:00

After I finished cutting, joining, and sanding the slats I noticed something about them: they have very sharp edges. "Sharp" is not a good property for kid's furniture. I decided to break the edges by adding a chamfer along the edge. I like a chamfer better than rounding -- it looks more refined.

Ordinarily I'd add a chamfer either by sanding, or using a block plane. But I've got 28 slats to shape, each with four edges -- that's 112 edges to chamfer! I need the process to be quick and produce a uniform chamfer on all edges. The ideal tool for this job is a router table with a chamfering bit. Since I don't have a router table and the parts are small, I clamped the router upside down in my bench vise.

This set up worked really well, and all I had to do afterwords was lightly sand the edge to clean it up.

40 Hours in the Desert

2008-08-01T09:57:00.007-04:00

Sanding. Ug. It's loud, dusty, and boring. But it's got to be done. Last weekend I made one pass over all the slats with P150 using my random orbit sander. P150 is good place to start to remove mill marks from the planer and sand away any tear-out in the curly maple. I still need to go to P220, and probably down to P320 before applying the finish.

So far I've been very careful to mark the slats, so that adjacent slats come from adjacent parts of the original board, and so that all the slats are oriented the same way. To this end I numbered the slats before they were cut, and marked each one with arrows indicating its final orientation. The problem now is that I need to sand the entire surface, including the markings. To solve this problem I transferred each number to the end of the bottom tenon, oriented so that outer face of the slat is up when the number is up. Obsessive? Perhaps. But I think it will pay off.

The next step is to glue the slats into the top and bottom rails. Once glued, however, the slats will be difficult to finish. So, my plan is to pre-finish them with two coats of shellac before they are glued, which will be much easier. The last picture shows a test strip finished with shellac on the top and boiled linseed oil on the bottom. I think the BLO is too yellow and doesn't pop the figure more than shellac. Plus, shellac is totally non-toxic -- in fact, it's used as a coating on foods, such as candy.

56 Bottles of Beer on the Wall

2008-07-25T09:58:00.006-04:00

Last weekend I made good progress on the front and back of the crib. These two parts are similar in that they both consist of cherry rails connected by a number of curly maple slats. How many slats, you ask? 14 -- on each side. That's a total of 28 slats, and each one needs two mortise and tenon joints (for the top and bottom.) So, that's 56 mortise and tenon joints to cut.

56 mortises is a job for a dedicated mortising machine, which performs the magical task of drilling a square hole. I bought this machine a while ago because I got sick of cutting mortises with a router, which requires a complex jig and results in a rounded mortise. A bench-top mortiser is essentially a drill press with a special hollow chisel bit that attaches to the head. Inside the hollow chisel is an auger bit that drills a circular hole -- the chisel on the outside squares up the hole.

Even with the mortising machine it takes a while to cut 56. The third picture shows the four rails, each with 14 mortises. The narrow rail is the top and the wide rail is the bottom. The wide rails will eventually be cut with a curve, but it's easier to clamp the joint before the curve is cut.

The next step is to cut tenons on each of the slats. Again, we've got 56 joints to cut, so it needs to be efficient. I could have used my table saw tenoning jig, which produces very nice tenons, but would take forever. Instead I set up the table saw with a dado blade, which is much faster, but cuts a fairly rough tenon. The last two photos show one mortise and tenon -- not a bad fit!

The bars

2008-07-15T22:07:00.004-04:00

Last weekend I finally got back to work on the crib: I cut the curly maple boards into strips that will become the slats. The band saw is a great tool for this job. First, the blade is thin and leaves a very narrow kerf, so very little wood is wasted. Second, it's simpler to cut uniform strips without a complex and dangerous set up, as would be required on the table saw.

The band saw jig is very simple: it consists of a wood strip cut to a rounded point at one end. The strip is clamped to the band saw table with distance between the tip and blade set to the width of the slat. The trick is that as long as the left side of the board touches the point, the slat will come out the right width, even if I don't hold the board perfectly straight.

The only downside of the band saw is that the resulting edge is rough. After each slat is cut, I re-joint the edge of the board before I cut the next slat. Once all the slats are cut I use the planer to get a smooth surface on both sides. The third picture shows a set of slats (for the front) all cut and planed.

In the last picture you can get a sense of what the front and back of the crib will look like with the rails and slats in place. Notice that I cut the slats from 6/4 curly maple, so the side of the board becomes the face of the slat (which is 5/8" thick). The next step will be to cut mortise and tenon joints along the top and bottom of the rails.

Woodworking Magazine

2008-06-16T16:59:00.005-04:00

I just discovered Woodworking Magazine, a quarterly publication that appears to be styled after Cook's Illustrated (one of my long-time favorites). It's not easy to find on the newsstand, and it only comes out four times a year. But I've seen two issues so far, and they were both excellent. The articles are very good, and like Cook's there are no ads.

Design

2008-06-15T13:26:00.002-04:00

We've finally settled on a design for the crib. It follows the style I've used in most of the furniture I've built: a mix of classic (Shaker-ish) and contemporary. I really like to mix woods, especially maple and cherry. The basic shape has a few gentle curves to it, but it's not overly swoopy and ornate (it is a boy, after all). I made the model using Google SketchUp (which is a fantastic program) and generated 2D images from it.

We've gone back and forth on the design of sides. Originally, the sides were going to be slats, just like the front and back. Recently we've been playing around with solid sides, which you can see in the pictures (the top picture shows solid on one side and slats on the other). The nice thing about solid sides is that we can add funky cut-outs: one idea is to have a moon and stars on one side, and a sun on the other. One tricky part: the cut-outs have to conform to the same guidelines for safety (i.e., no gap bigger than 2 3/8").

Gettin' the band back together

2008-06-06T19:36:00.002-04:00

Last week I received a wonderful birthday present: a new bandsaw! OK, I bought it myself, but my family contributed generously. After some research I settled on the Grizzly 14" model. It took the better part of a day to put it together -- and I had to get clever to get the saw (which weighs about 250 pounds) on top of the stand. I've only cut one board, but I can see that there's a learning curve. My knowledge of tablesaws is completely useless here: adjusting the bandsaw involves things like "tracking" and "tensioning". Once it's all set up, though, I have a feeling I'll wonder how I ever got along without it! (The dorky goggles shot is courtesy of my lovely wife.)

Jet plane (actually, Delta)

2008-06-02T10:40:00.003-04:00

Last weekend (actually a week ago) I thickness planed all the boards, which is a big, noisy, dusty job. Definitely not the fun part of woodworking. You can really see how pink cherry wood is when it's first planed. The curly maple looks great. The third picture shows the machine that does all the work. This process filled two of those giant paper leaf bags completely with saw dust.

The big problem now is the design: since I still haven't settled on the design I can't really take the next step. The general idea is to have a frame made of cherry and slats made of curly maple. We've been talking about making the sides solid wood, and perhaps having a design cut into them -- maybe a moon on one side and a sun on the other.

The Wood

2008-05-19T10:48:00.007-04:00

This is what a crib looks like before jointing, planing, ripping, cross-cutting, shaping, joining, gluing, sanding, and finishing ... man, I get tired just typing all the things that still need to be done. Most of the wood on the left is cherry. Several of the boards are 8/4, for the legs and top rails. The wood on the right is curly maple, which will be used for the slats. All the wood is rough-sawn, so it's hard to tell what the boards will look like.

The first step in the process is to joint each board, which makes one face of the board flat. After jointing, I'll use the thickness planer to make the second face parallel to the first. One minor oversight: some of the boards are 7" wide, but my jointer is only 6" wide. Hmmm. Since it's not safe to cut rough boards on the table saw, I had to trim them down to 6" using the saber saw. I wish I had a band saw, but all in all the jointing went very well.

The third picture shows all the boards with one face jointed. The color of freshly cut cherry is surprising: it's more like a pink or salmon than the deep reddish brown you'd expect. I met a guy at a an art show that told me to leave the finished crib in the sun to get that color. You can see his stuff here.

The last picture shows the curly maple after jointing. Some of the boards are better than others, but it looks great on the edge. My plan is to rip the slats off the side of the boards, so the edge will be the visible part.

Crib Part 1 -- Shopping at Sharps

2008-05-14T22:11:00.004-04:00

Last weekend we took the first step on our next project -- building a crib for our baby boy. The design is a three-in-one sleigh bed: it can be configured as a traditional crib, a toddler-size bed, or a regular twin-size bed. We're starting with a plan from InovateUSA, but we'll probably make style modifications. I ordered hardware from Rockler.

On Saturday we drove up to New Hampshire to buy wood from Sharp's Lumber. They were recommended to me by the guy I bought my jointer from. The company is run by Steve Sharps and his son Jamie, and you can't imagine two nicer guys. They spent a lot of time with us, letting us pick through piles of cherry and curly maple. Three generations of Sharps live on the property in houses they built themselves.

The top picture shows the inside of the lumber shop, which is filled floor-to-ceiling with amazing hardwood lumber. The second picture is the lumber shop from the outside. The third picture shows a big stack of gorgeous curly maple.

We also spent a nice afternoon in Ashland, NH.

XY

2008-05-13T16:17:00.007-04:00

This morning we went for our second ultrasound, an experience that blows me away every time. The radiologist we got for this appointment was great -- he found the important structures very fast and spent time showing us other things. We could clearly see the four chambers of the heart beating. Amazing.

Well, we were kind of expecting it to be a girl, but all the old wives' tales failed us. Aliza wanted to keep it a secret for a little while, but once you've told everyone that you're going to find out the sex, it's pretty tough to deny them! Her father still wants it to be a surprise; although once her mother starts working on a blue sweater I think it's going to be tough.

Aliza says the baby looks like me. True, he does dance around in there quite a lot. I'm not so sure, though. Have you seen that nose? Hee hee.

First post

2008-05-12T16:37:00.002-04:00

Have you ever used a manual "reel" lawn mower? As you push it through the uncut grass you eventually run out of momentum. So you stop, back up a few feet, build up some speed and plow ahead. I call this technique the lawnmower method, and it applies to many things in life, not just lawns!