March 22, 2017
Does Changing Speeds On A R.O. Sander Make A Difference?
Q. How should the speed and grit of paper be used on variable speed random orbit sanders? My background is in aerospace manufacturing. In metal machining, fewer cutter teeth equals lower rpm and more teeth will allow higher rpm. By this convention, lower grits would run at the lower speeds and the speeds would increase for the higher grits. Bigger grit equates to less teeth and smaller grit to more teeth. I usually apply this convention, but I have tried reversing it or just using the same speed for all. Really can’t see much difference in the final surface. Maybe your resources can shine some light on this, or did manufacturers just give us variable speeds because we thought we should have it? I know some still offer single speed along with the variable speed sanders. – Dennis S. Cropper
A. Dennis, as you point out, I’ve seen no real difference either in cutting efficiency by varying the speed of my sander relative to the coarseness of grit I’m using. I think the bigger issue, regardless of speed setting, is to not push down on the machine while sanding in an attempt to speed the process along. The sander should be allowed to spin freely and under its own weight plus light hand pressure. It ensures that the orbital action will work properly so the grit abrades the surface as efficiently as it can. Beyond that, I’m not certain that variable speed control makes much difference at all to the final surface smoothness. I set my random-orbit sander to maximum speed for any grit I’m using and leave it there all the time.
January 10, 2017
The most overlooked orbital sanding issue
October 04, 2016
What causes grain to raise up on boards we've just sanded?
April 28, 2016
Learning to Sand Wood by Experience
The objective of sanding wood is to remove mill marks, which are caused by woodworking machines, and to remove other flaws such as dents and gouges that may have been introduced in handling. The most efficient method of doing this is to begin sanding with a coarse enough grit of sandpaper to cut through and remove the problems quickly, then sand out the coarse-grit scratches with finer and finer grits until you reach the smoothness you want – usually up to #150, #180 or #220 grit.
You’ll have to learn by experience what works best for you.
October 30, 2015
Making your own Abrasive Belts
Every so often at Abrasive Resource, we get an email or call from someone that is interested in either repairing a broken belt or making their own belts at home and they are wondering if we sell any DIY belt splicing materials. Unfortunately, we do not…and here is why:
- The splicing tape is a specialized product designed for bulk abrasive belt manufacturing. It is very thin (from .0025” to .0085”), yet has a tensile strength up to 380 lbs/inch.
- The tape is manufactured with an exact thickness of dry, thermosetting adhesive that is applied to the yarn surface of the splicing tape.
- The rolls of tape are cut and wound into 76 meter lengths—that is the shortest length you can buy.
- They are sealed into a plastic bag and shipped frozen—on dry ice—in insulated cartons via air freight. Once they arrive at our facility, they are stored in a deep freezer at -20 degrees or lower to maintain their 90 day shelf life.
- After the abrasive material has been cut to the desired angle and length, the backing material is abraded and a special two part adhesive is applied to both belt ends.
- The tape is then applied and permanently affixed in a belt press, applying between 2000 and 3000 PSI at 165-185 degree temperature.
Tips to facilitate a longer life for your Sanding Belts:
Sanding belts DO have a shelf life! We always advise our customers to only order the quantity of belts they estimate they can use within a year.
- Don’t purchase abrasive belts in bulk to get “a better deal” and risk having the joint age out and potentially break in a year or two or three.
- In addition, do not buy sanding belts if you do not know when they were manufactured! Purchasing belts on closeout from a retail store that may not get enough traffic to “turn” their inventory or online from an importer is always risky since you do not know how long ago the belt was manufactured or the condition it has been stored in. Abrasive Resource makes all of their belts “to order” so you get the freshest belts possible!
- Store the belts in a dry, stable environment. Perfect conditions would be in a protected area that is humidity controlled like an air conditioned office, storeroom or shop.
- If a “new” belt breaks at the seam—one that you have had less than 90 days—then there is most likely some sort of manufacturing defect and they should be replaced by the manufacturer. Keep your broken belt (s) to show the manufacturer how they broke and they will be able to identify the reason and make sure that you receive a n/c replacement. It doesn’t happen often…but when it does, you want to make sure that you are able to directly contact the manufacturer of your belts to get the problem resolved quickly.
September 23, 2015
Choosing the right Fiber Disc for your grinding application
An angle grinder is a useful tool for any shop! You can use bonded grinding wheels, cut-off wheels, overlap discs or standard fiber discs all on this same tool for many different applications in metalworking, woodworking and stone or tile.
Abrasive Resource just lowered their prices on resin fiber grinding discs, so we thought it would be a good time to review all of the different applications where a fiber disc would be effective:
Aluminum Oxide: A general purpose abrasive used for metal or wood. Removes small welds and imperfections along with light stock removal, blending and finishing. Wood applications include log furniture and homes. These AO discs are also used in light-duty metal applications on low alloy steel or when loading is a problem, such as painted surfaces or aluminum.
Zirconia: The workhorse of the fiber disc world. Zirconia refractures for longer life when used in high pressure applications like stock removal on Chrome and chrome-nickel steel or high-alloy steel. Used for applications that include blending, deburring and weld removal. Generally lasts twice as long as an aluminum oxide disc when used in the proper application.
Ceramic: A premium abrasive for high heat generating applications such as stainless as it resists glazing and provides long life. The choice of metalworking professionals due to self-sharpening characteristics that provide high stock removal rates. Features cool cutting technology for reducing heat and increasing performance. Ideal for grinding and blending welds.
Silicon Carbide: Excellent on titanium, fiberglass, plastics, and stone, tile and masonry products. Sharp silicon carbide abrasive grain quickly “bites” to remove any coatings such as adhesives, paint, acrylics, mastics, etc. Aggressive cutting action provides a clean, smooth finish on concrete, marble, granite, and other stonework.
To purchase any of these discs at the new lower price, please visit the Abrasive Resource fiber disc home page on our website to find the discs best for you!
February 26, 2015
What are Non-Woven Abrasives?
Traditional coated abrasives are a cloth or paper backing that has abrasive grain “coated” or applied to one side. But a non-woven abrasive is composed of a synthetic substrate onto which a slurry of resins and abrasive grain are deposited. Non-woven abrasives are divided into two categories—they are either scrim backed, which is also known as surface conditioning products or non-scrim backed, which are the surface finishing, or open web products.
October 30, 2014
What do those arrows mean on the back of my sanding belt?
When sanding with a belt sander, you always want to make sure your belt is
oriented properly. Some sanding belts do have a preferred direction, and they
have been manufactured to consider the arrow on the inside. These arrows,
however, are only important to pay attention to when your belts have an
overlapped joint and there is a “bump” to be concerned with. In that case, you
will want the arrows on the inside of the belt to follow the same direction that
the belt is running on the sander. Most belts made in the United States---and all
of the sanding belts we convert at abrasiveresource.com -- are now manufactured with a high strength tape butt joint, and belts made with these butt joints can be
run in either direction . . . so it's OK to ignore the arrows. The tape spliced joints are bi-directional.
Bi-directional belts can be installed either way. The only adjustment you’ll probably have to make is “tracking” to keep the belt centered on the rollers. Hold the sander up, turn it on, and see if the belt either rubs against the housing or starts working its way off the rollers. With the trigger on, adjust the tracking knob until the belt is centered on the rollers. You may have to make a slight adjustment when the sander is on your work piece. If your sander has automatic tracking, you won’t need to be concerned with manually adjusting the tracking.
September 30, 2014
The basic styles of portable sanders haven’t changed very much over the years. We have some old advertising posters from the Rockwell Manufacturing company in 1964 matted, framed and hanging in our lobby here at Abrasive Resource and they, quite frankly, look a lot like sanders you can purchase today… although they do look much heavier! Sanding is a chore—there’s no way around it. But today’s new models can make it easier:
Random Orbit Sanders- Once the surface has been leveled with a belt sander, the next sander to use may be a random orbit disc sander. These sanders use an oscillating action that removes swirl marks. Random–orbit sanders may be palm sanders or have a grip design and are available in either a pressure sensitive adhesive (PSA disc) design or a hook and loop disc option.
August 27, 2014
Back to Basics: Cloth Sheets
discs, are ready to use right out of the box. But other sanding
supplies--like sandpaper or cloth sheets and rolls, usually need
to be cut to size before you are ready to sand with them. And
some abrasives benefit from being “broken in” before sanding
to improve their performance. Here are some “tried and true”
tips for handling cloth sheets:
- Cloth sheets can usually be torn evenly along
the weave of the fabric backing
by ripping carefully across the sheet from one edge to the other. Otherwise,
a utility knife cuts nicely from the back of the sheet. Common sizes are
4-1/2” x 5-1/2” and 3-2/3” x 9” for power sheet sanders.
- When sanding curved or irregular surfaces, your cloth
sanding sheet will
benefit from a little additional flexing. Just pull the back of a 9 x 11 sheet
over the edge of a benchtop or machine table. Then turn it 90 degrees and repeat.
- Even if you choose the most popular name brand
of abrasive, it won’t do
you any good if you continue to sand with that cloth sheet once it’s dull.
Change out your cloth sheet with a new one as soon as you notice it is
no longer sharp. Dull abrasive sheets require more energy to remove
stock, decreasing your productivity. In addition, they will contribute to
a poor finish on wood.
are available in grits 40-400. They are seen as a general purpose abrasive for
wood or metal and can be used by hand or attached to high speed vibrating
sanders. Abrasive Resource also converts custom-sized cloth backed sheets
for specific industrial or artistic applications.
For more information on cloth sheets, visit the Abrasive Resource website
or call us at 800-814-7358.