I learned today about what's called an "FTG" blade, which stands for "Flat Top Grind."
Being totally broke around Christmas-time really blows. But, it also forced me to use resources I had, to make something for Christmas. Three boxes out of exotic woods were the fruits of my resources. They turned out alright. They look best from a distance.
I left work at a major Denver hospital in September, with the intent to focus on school. For whatever reasons, although I devoted the time, the schoolwork wasn't sinking into my head. I was barely passing at the end of the first half of the semester of anatomy and physiology II. I studied my ass off when that midterm came. Then, on test day, I found that I was errant in my perception of the midterm's day: I actually had one more full week to study. I rejoiced, then I used that week. I made even more notecards, reviewed the homeworks, and I downloaded mp3's of lecture material from the textbook's publisher's website, listening to it regularly while driving or with headphones. I google'd and Youtube'd processes on hormone interactions and second-messenger systems. Thought I had it down. I still got a 60 on the midterm.
Thereafter, consistently poor quiz performance in the semester's second half sank my grade beyond the point of having a reasonable chance to pass. The day of the final came. I went to school early, but I didn't read my notecards or open my book. I went to the school's 1st floor, to a vacant music practice room with a grand piano. I played a Rachmaninov tune, then improvised harmonies of 2, 3, or 4 tones. A few minutes late, I went upstairs for the final, and partially opened the door to the lab. I saw a single row of students, looking down at the test, engaged. I closed the door and left without ever stepping foot in the room.
In the same week, I am declared ineligible for unemployment benefits (due to me leaving my prior occupation, which they deemed as "personal reasons"). My first thought was, "...and Christmas?" After triaging bills, I figured I could spend a maximum of about $200 on Christmas, total. I was already building a box for my mom, so I figured I might as well do the same for my girlfriend's brothers, whose company I thoroughly enjoy, and who have helped us in spades recently in many ways where we needed it.
One brother had visited us about a year prior. After one fine meal, cooked by him, he was reflecting on the the youthful occurrences of sibling rivalry. He summarized the lot of tales by stating something to the nature of, "I'm surprised he even talks to me anymore. I was very mean to him." Weeks later, we learned through a social media website that, after visiting us, he had gone to his younger brother's house, and they looked happy to be building (or repairing) a deck together in the younger brother's home. The more I thought about what I should build, the more it crept in to utilize the concept of brothers: making different boxes, but that work with each other.
Also, I wanted to go to a craft store and get a fabric that is of good quality. Having seen a good amount of finished boxes, and having visited many woodworkers' blogs, I could never understand why they would spend the time to build a highly-accented box and/or one out of exotic woods, and then, on the interior, apply an adhesive-backed cheap textile, or a faux-suede lining. I needed (and found) a good quality fabric that had both the color tones of the padauk, and the bloodwood.
|Bookmatched pieces of padauk.|
So I began. I only had two big pieces of exotic hardwood lumber: one of bloodwood, and one of padauk. Both were 7/8" thick, 5 - 6 inches wide, and roughly 2.5' long. Their width meant that I could both rip them in half on the table saw, AND used the bandsaw to re-saw the thickness to 2 pieces roughly 3/8" thick. Resawing the wood on the bandsaw also gave me book-matches pieces that were beautiful.
|Kitchen table as my workbench. My girlfriend and her mother are angels of patience to me.|
|Hinges, (for different box) made out of padauk and Jarrah, with brass rod.|
That gives me enough material to make the boxes' square frames, and the lids, and leftovers to make the hinges out of wood. Only when I was cutting the wood did I notice that the cut of padauk I had features darker red tones that allude to the bloodwood's lighter tones. I decided that both boxes will feature both woods. Not only that, but almost as opposites of each other: the parts of one that are bloodwood will be padauk on the other, and vice-versa.
Unfortunately, although I have a planer/joiner that could flatten the boards, I didn't have a thickness planer. I learned, in the production of these boxes, how integral that is to the quality of a whole project. Usually, you run one of the faces of the boards through the planer until the machine flattens the whole side. Then, if you have a thickness planer, you put the newly-flattened side down on the thickness planer and run it through. The thickness planer's blades on the top side of the machine references your freshly-flattened bottom side, and cuts the top perfectly parallel to it. You continue to run the board until the top is totally flat as well, and then you're pretty much guaranteed that both sides are not only clean and smooth, but also totally parallel. After that, you run one of the edges of the board over the joiner until its flat, then put the board on your table saw (with the flat, jointed edge against the fence), and you cut the side that is un-jointed. That's what they call "4-squaring" a board: all surfaces are square (90 degrees) to each other. Without the thickness planer, I tried as best I could to run both sides through the planer/joiner. The problem is, especially after a re-saw, one edge of the board is bound to be thicker than the other.
To try to cut miters and angles on wood that is not "4-squared"... well, the miter cuts might be dead-on, but the problem you have is during assembly and glue-up: you say to yourself, "Which edges should I line up? How much can I afford to assemble and glue-up the box out of square, and how can I compensate for it and clean it up later?" Ultimately, you can do it, but it will probably be noticeable, as well as cost you more time in sanding to try to even things out. I vow to never go down that road again. Although it's not blatantly obvious, this picture does show that the edge of the mitered piece (near the bottom right of the photograph) does have one side a bit thicker than the other:
During the planing/jointing process, the grain of the padauk was going in beautiful-but-crazy directions. This caused the blades of the planer to rip out some serious-sized chunks in three obvious locations. I couldn't afford to plane the board down any thinner than it was, as it wouldn't match the thickness of the other pieces. Besides, if I did try to plane it thinner, there was no guarantee it wouldn't just tear it up even more. I decided that, after assembly, I would try to fill the gouges in the padauk with clear epoxy, then chisel and sand it flush to the surface. The results turned out better than I imagined, as the clear epoxy lets light through to the actual grain, resulting in no visual defect. Often times, in wood that has holes or gouges, woodworkers will fill these with epoxy, but also with some of the wood's sawdust, so as to keep the color consistent. The only thing is, with well-defined grain patterns like I had, color was NOT the issue. Color was highly variable, as was grain direction. To try to add sawdust would probably result in making a color-and-grain-interrupting "spot" of roughly one color.
|Filled with Dev-Con 5-minute epoxy, allowed to dry/cure 30 minutes, then start to sand it down.|
|The gouges in the wood are near the knots (top of the photo) and are not very noticeable at all after sanding and finishing.|
I learned one lesson the hard way twice: do all cutting and drilling in a predetermined sequence, and make sure this sequence utilizes the strength of the wood. Regarding the making of the hinges, I made one set for the padauk, and they were fine. I "finger-joint-style" cut the grooves on the table saw, and then I drilled through that with the drill press. Padauk is much less dense than bloodwood, though, and when I tried to do the same with bloodwood, I ended up breaking or burning my first two sets:
So, I not only learned about the importance of considering the order of operations, as well as the importance of considering the direction (and thus function) of the wood grain in every aspect, but I also learned about bloodwood. Australian bloodwood is super-stringy, or at least the cut I had of it was. Both machine and hand-planing resulted in incomprehensible chunks coming out, as if I were working with glass or ice. And it burns real easy. Glue couldn't save this set (largely for aesthetic reasons), but the way around it was by changing the order of the process: do the fine work first (drill one deep hole that will be for all four pieces of the hinges). Grain integrity/strength while the wood is one solid piece helped prevent burning & splitting. Then, I divide that one piece into four for the hinges, cut them finger-joint style on the table saw, fit 'em and file them over from there.
However, I made errors in the glue-up of the hinges to the wood box:
The bottom edge isn't very parallel to the box. These were the padauk hinges I made for the bloodwood box, and I think I epoxied them on instead of glue. This was a mistake. The epoxy acted like a thick gel, and while trying to clamp it down, it slid around on this "gel-like pad," skewing the layout. As resolution, in the future I'll place and mark the bottom edge of where the hinges need to be, then clamp a dry, squared up, temporary board along this line across the whole back. In that way, I can rest the hinges on the board, and it will be harder for them to be out of line. Also if the hinges move during gluing/clamping, it will be more obvious. Another thing: don't epoxy them, glue them. Epoxy, when it dries and cures, is actually quite brittle. One set of hinges popped of the lid after a day. There was too much resistance in the hinges at that time, and that pulled it right off. Glue, on the other hand, binds the fibers of the wood together better, and accommodates a little bit of flexion.
The reason I had started this story with the FTG (or "Flat-Top Grind") blade, is because it is necessary to reduce work: for both making the hinges and the splines (angled slats cut into the outside corners of a box that add strength and afford embellishment). The typical angle on a cross-cut or cross-grain blade's teeth alternates. This is insignificant if you use it for its intended purpose: cutting through the whole board to achieve a certain length. However, if you use this type of blade to cut a specific depth into wood, that alternative bevel becomes obvious, and winds up leaving you with a miniature peak at the bottom of the cut. Since I was unaware, and used and cross-cut, alternating-top-bevel blade for all cuts made on the table saw, my splines wound up with little peaks in them that I had to try to cover up with epoxy. This was my second error with the splines. Also, the troughs of my hinges (which I had cut finger-joint style on the table saw) wound up with ridges in them, which I had to try to file out as evenly as I could. The close up of the hinges above Tenryu's blade tooth chart shows that there are still some indicators of the ridges left, even though I had filed them to a point that I thought was safe without bowing the crisp outside edges of the troughs of the hinges.
With the hinges done, and with them opening from 90 to 200 degrees or so, I took my glued-up box, and ran the corners of it across the table saw with a box-maker's jig. The design of these jigs varies, but essentially they hold the box on its corner, 45 degrees off the surface of the table, so that you can run the box through the saw blade (or an angled saw blade) and get a nice clean spline cut through the corner. Splines strengthen the joint, as well as give you the chance to accentuate the corner with another wood. I made three errors in my application of this. On the bloodwood box, I wasn't mindful of how close my third (and angled) round of cuts was to my first, and the blade ended up removing a whole section of one of the corners, as shown here filled (but not grain-matched very well):
|What runs through my head when I see this is the Sesame Street song:|
"Which on of us is not like the other... Which one of us does not belong..."
The third error on my splines was in not being mindful enough of using a very fair-colored piece of wood for the keys, and also, not paying enough attention to the grain direction of the keys. The color of the key is always darker on any edges of the keys where the grain visible is end-grain.
I made the top panels after mitering the corners of the frame and gluing it up in place with a box clamp. It then occurred to me that I should have made a channel in the frame, so as to adhere the top panel onto the frame instead of trying to squeez it into the frame. I didn't think I'd have a fair shot at creating this channel after the frame pieces were glued up, so I didn't go that route. Although the panel of bloodwood was bigger than the padauk frame I made for it, the padauk panel I had planned for the bloodwood frame was smaller. I ended up having to bump out one edge about 1/8".
|Bump out of top left side of frame on bloodwood box; padauk panel was too small.|
|Glue gap at lower-right corner between padauk and bloodwood frame|
|Orbital sander held too long on the lid, leaving indentations|
that I couldn't afford to try to correct (given how thin it would have made the lid)
See the rings near the front corners? The high-gloss finish makes it more obvious.
Once the build of the boxes was complete, I made an error in my sanding: not being mindful of how much I'm removing. I was so focused on trying to clean up where the frame meets the top panel, that now the rings from the orbital sander are permanently embedded in the box's lid.
Ultimately, they did turn out okay -- the metaphor is still there: boxes that are literally (historic) pieces of each other, and an interior that is cut from the same (genetic) fabric.