Are you interested in grinding welds with a flap disc?

Overlap flap discs grind like a depressed center wheel and blend like a fiber disc all in one operation, reducing production time and lowering costs.

Premium closed coat blue Zirconia abrasive flap discs are the best all-around overlap disc capable of fast cutting, long life and superior finish. Backing is made from non-flexible consumable fiberglass.Choose from either standard density or the thicker, high density Xtreme disc. Use in place of a grinding wheel or fiber disc on a right angle grinder for stock removal, grinding and blending of welds, castings and other metal finishing.

Choose from Type 27 flat discs that are designed for finishing on flat surfaces and used at up to a 15 degree angle or the Type 29 conical discs, which are to be used at a 15 - 25 degree angle and are the best choice for speed and maximum stock removal.

Please go to the Overlap discs on our website and find the size that works for your grinder.

Please watch this great you tube video by Kevin Caron on how to use these flap discs . . .

You can "Reclaim" your used Resin Fiber Discs

Are you tired of paying $2.00 and $3.00 for a 7" x 7/8" zirconia or ceramic fiber disc and only using the outside inch or two in your shop? It’s such a waste of money…

Don’t you wish there was an easy way to cut them down so you could “reuse” the disc on a smaller 4-1/2” or 5” grinder? Less waste and better for the environment…

Now there is a way! Abrasive Resource will laser cut your used fiber discs into smaller sizes and ship them back to you so you can reclaim them for another grinding cycle…

          ~  Most heavy grinding occurs on the outside periphery of a 7 x 7/8 resin fiber disc.

          ~  After this “first” use, discs can be boxed up and sent to Abrasive Resource to be laser 
              resized with Laser Blade technology to 4-1/2” x 7/8” or 5” x 7/8” grinding discs.

          ~  Your reclaimed discs are shipped back to your plant within 2 weeks—freight paid.

          ~  Cost is based on order volume and starts at $.50 a disc with a 1000 piece minimum 
              order.

 For more details or a custom quote, give us a call at 800-814-7358.

Eliminating chatter marks when wide belt sanding wood

Chatter marks are the most common sanding defect and problem when widebelt sanding wood and can come from different sources. Common causes and solutions are:

• If the marks are uniformly spread across the board, the rollers being out of balance can cause the problem, or the bearings may be worn. The rollers may have become “oval” or the pad, where fitted, may have become stuck.

• Another cause can be vibration caused by poor machine mounting or loose foundation plates. The spacing between the chatter marks will indicate whether it is the contact roller or a defective abrasive belt.

• Splice marks are similar to chatter marks but are caused by a poor belt splice. There is a difference between the frequency of marks caused by a splice and chatter marks from a roller. To see if the marks are from the drum or the splice, sand two workpieces, one at a fast conveyor speed, and the other at a slow conveyor speed. Compare the marks; if the marks are similar it is chatter from the drum. If the spacing of the marks is different, the abrasive belt splice causes them.

• Make sure your contact roller has the proper rubber hardness (durometer) for your application. Experts recommend a durometer of 60 for most sanding applications. Harder contact rollers will take off more material but they are also less forgiving increasing the likelihood of unwanted marks.

• Use a platen for finish sanding. The platen will sand less per pass and also spreads the sanding over a larger surface area because it is actually wider than the contact roller. Running your material through a couple of times during the finishing process with the platen activated should give you a nice smooth finish.

• Slow it down – Running your conveyor belt slower will allow more time for abrasive sanding to remove the chatter marks.

• Other actions to cure chatter include: Use an abrasive belt with a butt splice; replace the contact drum bearings; replace the drive motor bearings; tighten the drive belts; replace or dress the contact drum; balance the contact drum; check the conveyor bed drive coupler/drive belt; and relieve tension from the abrasive belt when it is not in use to avoid flat spots on drums.

To read the original blog post, please check out the Woodworking Network.

For sanding belts from Abrasive Resource, please check out the Sanding Belts on our website.

Traditional Synthetic Abrasives-A Modern History

 Silicon carbide was discovered by the American inventor Dr. Edward G. Acheson in 1891 while attempting to produce artificial diamonds from coke and silica sand.  Finding that these new crystals approximated the hardness of diamond and immediately realizing the significance of his discovery, Acheson applied for a U.S. patent. His early product initially was offered for the polishing of gems and sold at a price comparable with natural diamond dust. The new compound, which was obtainable from cheap raw materials and in good yields, soon became an important
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As an abrasive, Silicon Carbide is black in color and is the hardest and sharpest of the minerals used commonly in coated abrasives. It’s harder than Aluminum Oxide but considerably more friable—which means that it fractures readily, exposing new sharp edges. Silicon Carbide is most effective with non- ferrous metals such as brass, copper, bronze, magnesium, titanium and aluminum where fast, cool cutting is desirable.  Non-metallic applications include ceramic, stone, glass, plastic, leather and rubber.  Silicon Carbide is superior to any other abrasive in its ability to penetrate and cut faster under light pressure.
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Aluminum Oxide was introduced in 1900 by CT Jacobs.  It is produced from the raw mineral Bauxite where it is fused in electric arc furnaces at temperatures up to 2600’ C, which is a temperature 800’ C hotter than lava in a volcano! The AO ingots are cooled and then crushed with a roll crusher to produce a large volume of splintery, sharp and friable abrasive particles that break down easily to remain sharp and produce a minimum of heat buildup. The crushed AO is then sized into the various grits used in producing coated abrasive products.
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Aluminum Oxide remains the most popular abrasive used in sanding products, as it is considered the most “all purpose” abrasive.  It is a reddish-brown in color, extremely tough and its blocky shape facilitates the penetration of tough materials without excess fracturing or shedding. It is specified for applications on high tensile materials such as carbon steel and alloy steel as well as wood, composites and solid surface. 
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These traditional synthetic minerals used in abrasives offer many advantages over the traditional naturally occurring minerals. Synthetic minerals are consistent without unforeseen impurities. In addition, we have the technology to control the grain characteristics in a synthetic mineral.  Grains for coated abrasives are different than the grains used in grinding wheels. They are elongated to achieve the best bonding results and abrasive performance.

Aluminum Oxide is manufactured in two levels of abrasive grain surface density: closed coat and open coat. A closed coat product is one in which the abrasive grains completely cover the surface of the backing. The greater number of “abrading points” per square inch results in a larger amount of material being removed before the product becomes worn out. An open coat product is one in which the abrasive grains cover approximately 50% to 60% of the coat side of the backing. Open coat AO frequently cuts faster and provides a greater resistance to loading, which makes it an ideal choice for sanding on softwoods.

Sanding Belts & Grinding Metal

Abrasive Resource can have sanding belts made up for you in any width or length you may need for grinding or polishing metal. We show the more popular sizes in an aluminum oxide material on our Sanding Belts page, but we can custom fabricate any size, grit or abrasive material you require in just a day or two!

Offhand grinding on metal is the most traditional way to use sanding belts and covers all the methods of abrading metal where the operator holds the workpiece in their hand and presents it to the abrasive belt (as opposed to the piece being held in a fixture.)

This type of grinding is done on a Backstand Sander—also called a polishing jack or belt grinder. These machines vary considerably in horsepower, ranging from one to 75 HP. Typically, units with 7-1/2 to 15 HP provide a good working power for most applications at speeds between 3500 and 7000 sfpm. All grinding should be below the center line of the contact wheel and the workpiece should be brought up to the belt.

Optimum belt speed depends mostly upon the material you are grinding. Testing indicates that as the belt speed increases, so does the amount of metal being removed. However—as belt speed increases, the amount of heat generated also increases which may result in premature dulling of the abrasive grains (glazing) and/or heat damage to your workpiece.  The optimal speed range in sfpm for grinding belts is shown in this table:

Next you need to factor in grinding pressure. Pressure is an important part of the grinding process as it causes the abrasive grain on the belt to fracture and create a continuing supply of fresh, sharp cutting edges. An operator will generate this pressure against the contact wheel in a range of 20-50 psi. On an average offhand operation of moderate stock removal, a 70-75 durometer rubber contact wheel is the most useful. For more information on contact wheels, refer to our 2005 Sandpaper Blog post “Contact Wheels for Abrasive Belts”.

Finally, remember to check that the abrasive belt, idler assembly and contact wheel are enclosed within a sheet metal hood when using a backstand grinder. The hood must confine flying sparks and fumes as well as protect the operator from a belt breakage.

Abrasive Grinding

It’s January 2013 and the beginning of a new year is always a good time to think about learning something new or improving on what you already have, right? So for Abrasive Resource this means we are spreading our arms just a little wider this year. For the last sixteen years we have been your “go to” source for coated abrasives—sanding belts and sanding discs. Now we are welcoming some bonded abrasives into our product line, and I think you’ll like what you see!
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For years our customers have asked us for abrasive grinding wheels—whether you use them for auto body work, sharpening tools or metal fabrication. Now we have partnered with Camel Abrasives to offer you the most requested bonded abrasives line from over the years.  These abrasive grinding wheels are used on cut off saws, die grinders, angle grinders and bench grinders. 

Using Bonded Abrasives

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When using bonded abrasives, always follow these recommendations:

• Allow the wheel to attain full speed before it touches the workpiece.
• After installing a wheel, test run the tool for 60-90 seconds before touching the workpiece.
• Use gentle pressure when touching the wheel to the workpiece.
• Cut or grind with a smooth, even pace. Do not force the wheel…but do not proceed so slowly that burning occurs.
• Do not exceed cutting capacities as specified on the wheel by Camel Abrasives.
• Wear eye and ear protection, gloves, a long sleeve shirt and any other safety gear recommended by your tool’s manufacturer.
• Never use a dust collection attachment when cutting metal.
• Do not use cutting lubricants with cut-off wheels and only use them on grinding wheels if specifically endorsed by your tool’s manufacturer.

For more information on the types of abrasive grinding wheels Abrasive Resource is now carrying visit our abrasive grinding page at abrasiveresource.com.