10 - Heavy Duty Lathe Stand, страница 26
Sanding • Products A new breed of sanding products that claim to be longer lasting, maybe even "permanent." it exposes fresh minerals for additional sanding. splice. The secret to making a belt bi-directional is the splice that holds the belt together. On a conventional belt, the belt is overlapped and glued together, see Fig. 1. This creates a "bump" in the belt which can only travel in one direction without breaking. To solve this problem, a butt joint is used, see Fig. 2. It's held together on the back side with heavy tape. This allows the belt to travel in either direction without coming apart. It also means the belt will run smoother with less "bumping." grits. Bi-directional sanding belts are available from both Norton and 3M in grits ranging from 50 to 150 (Norzon is available in 180 grit). Note: Norton the surface shears off to expose new sharp edges. In other words, it's self-sharpening. 3M's man-made mineral, Re-galite, is a ceramic-like mineral that's harder than other abrasives. It lasts longer simply because it stays sharp longer. bi-directional. Besides using longer-lasting minerals, both companies have increased the life of their belts by making them bidirectional. This means you don't have to worry about direction when you load the belt on your sander — it goes on either way. This provides an additional 15% to 25% more life from a belt that has started to lose its cutting power. Why? Because reversing a worn belt helps clean it by dislodging wood particles stuck in the surface. And at the same time ometimes it seems that I spend more time changing sandpaper than I spend sanding. So when I came across some new products claiming to be longer-lasting, even "permanent," I was intrigued. NEW BELTS One product that has seen a lot of change recently is sanding belts. Two of the big names in abrasives (Norton and 3M) have developed a new line of sanding belts. Both belts are easy to identify — the Norton belts are blue, and 3M's are purple, see photo below. Each feature a man-made mineral that lasts longer than garnet or aluminum oxide sandpaper. The mineral Norton has developed is called Norzon. As this mineral gets dull with use, part of m 3M's purple sanding belts feature a ce-ramic-like mineral that stays sharp longer than conventional sanding belts. M Norton's blue sanding belts use a self-sharpening mineral called Norzon to last longer. 3 • ENDS of BELT OVERLAP CONVENTIONAL BELT BUMP IS CREATED -HEAVYTAPE REINFORCES BUTT JOINT BI-DIRECTIONAL PELT ENDS OF BELT 26 ShopNotes No. 10 |
