91 - Planer Stand, страница 35
of holes, I like to use a lubricant to reduce friction and heat buildup. Now there are all sorts of liquid coolants and lubricants you can use. But most create quite a mess. So 1 like to use a wax-like lubricant (inset photo at bottom of opposite page). You simply touch the stick to your drill bit while drilling. And the heat from drilling melts the lubricant, reducing friction. Tapping Threads. Another operation that can generate a lot of friction is tapping threads. Even though aluminum is relatively soft and easy to tap, I still like to use a few drops of lubricant. You can buy cutting fluid specifically designed for aluminum (main photo on opposite page). It makes tapping easier and cuts cleaner threads. Riveting. For some projects, like the squares on page 36, you want a permanent assembly. In this case, a simple rivet will do the job. But there's something I've learned about using aluminum rod for rivets. If the rivet doesn't slip all the way into the hole fairly easily, you can't force it in with a hammer. That's because the aluminum will expand as you try to drive it in. So, I like to make sure the rivet slips freely all the way into the hole before I touch it with a hammer. Then once the rivet is fully seated, it's easy to "mushroom" the ends to lock it in place (left photo above). ▲ Filing. A file makes quick work of smoothing the rivets flush with the surface of the workpiece. Final Smoothing. On a riveted assembly, there are a few more things to finish up. For the rivets, all you need is a metal file to cut them flush, like you see above. And since the edges of bar stock can be a little rounded as they come from the supplier, you can square them up with a carbide blade on the table saw (upper right photo). A push block and a very light cut make it an easy and safe operation. The next thing to do is sand all the surfaces smooth. The inset photo ▲ Tapping Threads. Cutting threads in soft aluminum is a snap with a hand tap and lubricant. ▲ Riveting. A few taps with a ball pein hammer will "mushroom" the ends of the rivets for a tight fit. ▲ Trimming Edges. A notched push block makes it safe to trim aluminum with a carbide blade. ► Sanding. To keep the sides square and sanding marks straight and even, use the rip fence as a guide. above shows a trick for keeping the edges square. And finally, the box below shows you how to protect and polish aluminum for a professional finish on your project. A Surface Protection: Wax or Lacauer ▲ Wax. A couple coats of paste wax adds a nice gloss and keeps the aluminum from staining your hands black. ► Lacquer. Another option is a coat of lacquer to add long-lasting protection and shine to your aluminum projects. 35 |
