Sandpaper is graded based upon the number of abrasive particles per square inch that make up the sandpaper. The lower the number, the more coarse the grit.
Sandpapers are commonly graded as:
• Coarse (40-60 grit)
• Medium (80-120)
• Fine (150-180)
• Very Fine (220-240)
• Extra Fine (280-320)
• Super Fine (360 and above)
Sanding with progressively finer grits removes the scratches left by the previous paper and eventually leaves a smooth finish.
You might be asking, "Why can't I just sand the entire project with Super Fine sandpaper?" Well, there's nothing saying that you can't. However, coarse grit papers will remove material fast, and when followed by finer grit papers, makes for much easier and quicker sanding. As almost any experienced woodworker will tell the beginner, the quicker you can get through with the sanding, the better.
Re: Choose the Right Grit for Wood
Grading Sandpaper:
There are two primary types of sandpaper: commercial grade and industrial grade. The differences lie in a few areas, namely the material used as the grit, the backing material (paper) and the glue used to hold the grit onto the paper. KOBE sandpaper is industrial grade that uses higher quality materials for all three components.
Additionally, you may see sandpapers that are rated as either "open-coat" or "closed-coat". The difference is that closed-coat sandpaper has the grit particles grouped more closely together, where open-coat sandpapers have larger gaps between the particles. As a general rule, open-coat is typically better for woodworking, as it clogs less often, particularly when working with softwoods that contain more resin.
Types of Abrasives:
There are five main types of sandpaper available, but not all are conducive for woodworking. Glasspaper, also known as flint paper, is very lightweight, typically a pale yellow color. Glasspaper disintegrates easily, and is rarely used for woodworking.
Garnet paper is usually a brownish-red color, which is commonly used in woodworking. It will not sand wood as quickly as other sandpapers, but leaves a better finish. Garnet is an excellent choice for finish sanding.
KOBE Aluminum Oxide Finishing Paper is the best type of sandpaper for woodworking projects. KOBE Aluminum Oxide is more durable than Garnet paper, with a great finish.
Silicon Carbide paper is typically a dark gray or even black. This type of paper is used primarily for finishing metals or for "wet-sanding", using water as a lubricant. While some advanced finishes use Silicon Carbide paper, it is not typically used in woodworking.
Finally, Ceramic sandpaper is made of some of the most durable abrasives available, and can remove considerable amounts of material in a hurry. Ceramic paper is often used for belt sander belts, but sometimes is used for hand shaping of wood. It will usually leave a very rough finish, so exercise care when using Ceramic sandpaper, particularly on plywood and veneers, where it can quickly sand through the finish layer and ruin a piece.
Re: Choose the Right Grit for Wood
Tip for a Great Finish:
In most general woodworking applications, you'll likely find that starting with varying coarse-grit KOBE Aluminum Oxide sandpapers for the initial sanding steps followed by finer-grit KOBE finishing papers will leave a very smooth finish that will show off your woodworking skills and give you a very nice platform for staining or painting your woodworking project.
The Five Rules of Sanding
Rule 1 -
Sandpaper is a cutting tool, use industrial grade KOBE sandpaper.
Don't use worn-out coarse grit as a substitute for finer grit. Worn-out 120-grit is just that, and it cannot be used as a substitute for 280-grit.
The spaces between the grit particles are like the gullets of a saw blade. The grit can't remove wood when the spaces are full. Use KOBE open-coat sandpaper to eliminate this problem.
Rule 2 -
Refine the shape, remove all tool damage and torn grain, and repair the surface with as coarse an abrasive as necessary to do the job - BEFORE moving through the finer grits...
The only purpose for all subsequent sanding with finer abrasives should be to refine and remove the scratch pattern made by the coarsest paper. If there is torn grain or other tool damage on the surface, go straight to a 60-grit, and don't fool around with anything finer. It makes no sense to brag about never using anything coarser than 180-grit, and then spend two hours to do the same job that could have done in ten minutes with 60-grit. The finer grit can be used, and for a shorter time, when we have improved our tool handling skills during the turning phase of our work.
Rule 3 -
Sand through all of the progressively finer grits without skipping any of them, and don't quit before 320.
I usually start with 60 or 80, and proceed through 120, 150, 180, 240, and 320, using whatever combination of power and/or hand-sanding that is appropriate to the task. It is much faster to use all of the abrasive grits in the smallest increments possible, than to make large jumps in grit size. This is particularly true at the coarse end of the scale. Of course, we could go directly from 60 to 320 grit if we had a lot of time and sandpaper to waste.
Rule 4 -
Remove all of the scratches and the sanding dust from the previous grit before going to the next finer grit.
This step is faster when Rule 3 is also observed.
Rule 5 -
Slow is good, and slower is even better.
There is a universal tendency to sand too fast. Heat is the enemy. Keep the sanding medium cool by sanding slowly. And, the slower moving abrasive will remove more material than one that quickly "skates" across the wood surface.
Don't spin the piece in the lathe so fast that the paper gets hot. If it burns your fingers, it is also burning the wood surface, and casehardening rather than cutting it. We have all experienced the situation where the sandpaper quit cutting, and it took a coarser grade to break through the surface glaze, only to have the same problem when we used the finer sandpaper. When this happens, slow down. I typically sand with a maximum lathe speed of 250 RPM for most work.
It is very easy to generate too much heat when power sanding because we have no direct touch with the abrasive. Heat will clog the disc, and destroy either the cloth backing or the sponge rubber on the arbor. Just because we have an electric drill with a top speed of 2400 RPM doesn't mean that wide-open is the best speed for sanding.
The slower speed will remove more wood faster, the disc is easier to control, there is very little airborne dust, and the sanding discs will last longer. . I use a 3/8" Black and Decker Magnum drill for power sanding wherever it will reach because it has an excellent trigger control and it will run continuously at less than 150 RPM.
Re: Choose the Right Grit for Wood
Thanks for the info!
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Re: Choose the Right Grit for Wood
Tip for a Great Finish:
In most general woodworking applications, you'll likely find that starting with varying coarse-grit KOBE Aluminum Oxide sandpapers for the initial sanding steps followed by finer-grit KOBE finishing papers will leave a very smooth finish that will show off your woodworking skills and give you a very nice platform for staining or painting your woodworking project.
The Five Rules of Sanding
Have you heard of Raising the grain?
Rule 1 -
Sandpaper is a cutting tool, use industrial grade KOBE sandpaper.
Don't use worn-out coarse grit as a substitute for finer grit. Worn-out 120-grit is just that, and it cannot be used as a substitute for 280-grit.
The spaces between the grit particles are like the gullets of a saw blade. The grit can't remove wood when the spaces are full. Use KOBE open-coat sandpaper to eliminate this problem.
How are they any better than competition? Compare same type of course.
Rule 2 -
Refine the shape, remove all tool damage and torn grain, and repair the surface with as coarse an abrasive as necessary to do the job - BEFORE moving through the finer grits...
The only purpose for all subsequent sanding with finer abrasives should be to refine and remove the scratch pattern made by the coarsest paper. If there is torn grain or other tool damage on the surface, go straight to a 60-grit, and don't fool around with anything finer. It makes no sense to brag about never using anything coarser than 180-grit, and then spend two hours to do the same job that could have done in ten minutes with 60-grit. The finer grit can be used, and for a shorter time, when we have improved our tool handling skills during the turning phase of our work.
Why would someone brag for stupidity?
Rule 3 -
Sand through all of the progressively finer grits without skipping any of them, and don't quit before 320.
I usually start with 60 or 80, and proceed through 120, 150, 180, 240, and 320, using whatever combination of power and/or hand-sanding that is appropriate to the task. It is much faster to use all of the abrasive grits in the smallest increments possible, than to make large jumps in grit size. This is particularly true at the coarse end of the scale. Of course, we could go directly from 60 to 320 grit if we had a lot of time and sandpaper to waste.
Why must we waste money on KOBE sandpaper when most sandpaper will finish bare wood at 220 grit. Some of your tips are good, but really have you made any tests? and why start at 60 grit? don't you have any other tool to cut the material close enough to sand as little as possible?
a 220 grit sandpaper on bare wood will give you the same result as a 600 grit making steps after this a waste.
Rule 4 -
Remove all of the scratches and the sanding dust from the previous grit before going to the next finer grit.
This step is faster when Rule 3 is also observed.
Rule 5 -
Slow is good, and slower is even better.
There is a universal tendency to sand too fast. Heat is the enemy. Keep the sanding medium cool by sanding slowly. And, the slower moving abrasive will remove more material than one that quickly "skates" across the wood surface.
Don't spin the piece in the lathe so fast that the paper gets hot. If it burns your fingers, it is also burning the wood surface, and casehardening rather than cutting it. We have all experienced the situation where the sandpaper quit cutting, and it took a coarser grade to break through the surface glaze, only to have the same problem when we used the finer sandpaper. When this happens, slow down. I typically sand with a maximum lathe speed of 250 RPM for most work.
It is very easy to generate too much heat when power sanding because we have no direct touch with the abrasive. Heat will clog the disc, and destroy either the cloth backing or the sponge rubber on the arbor. Just because we have an electric drill with a top speed of 2400 RPM doesn't mean that wide-open is the best speed for sanding.
The slower speed will remove more wood faster, the disc is easier to control, there is very little airborne dust, and the sanding discs will last longer. . I use a 3/8" Black and Decker Magnum drill for power sanding wherever it will reach because it has an excellent trigger control and it will run continuously at less than 150 RPM.
Heat will not clog a sandpaper... well maybe the KOBE sandpaper would according to your test.
Are you referring to a Magnet drill? can you post a picture of this model? And why would you sand wood with a drill? sanding holes? it doesn't make much sense to test sand paper with a drill... there is a new invention called a sander, it uses sandpaper... I do know a drill is designed to use a drill bit for drilling holes.
You selling the sandpaper? Hope you can make a good review of your product, why we should even consider using it... is there any technology in this sandpaper that is any different than the rest?
"Industrial" is an overused term that hardly gets anywhere anymore.....
click my signature and it will take you there........
Re: Choose the Right Grit for Wood
Hi dear am newbie here and i want to say that i have 40g is used to remove stuff really quickly, you will be left with nothing to glue together. I would use like a 120 or even finer. But I know nothing about glueing multilaminates, but I don't think you need a rough surface to glue. When you glue lumber together you can get it very fine and it blues fine. The challenge is in making sure your surface is clean of the stuff you sanded off.
Re: Choose the Right Grit for Wood
Hi dear today i want to say that i have 40g is used to remove stuff really quickly, you will be left with nothing to glue together. I would use like a 120 or even finer. But I know nothing about glueing multilaminates, but I don't think you need a rough surface to glue. When you glue lumber together you can get it very fine and it blues fine. The challenge is in making sure your surface is clean of the stuff you sanded off.
Re: Choose the Right Grit for Wood
What grit size would you suggest in the 1st sanding (rought) of palochina?
Re: Choose the Right Grit for Wood
What grit size would you suggest in the 1st sanding (rought) of palochina?
Palo China is very soft so be gentle with it in sanding. Depending on how rough the material is, you can start as low as 40-60 with gouged/dented palo china and would prefer to sand than plane. Normally though, I'd plane then start with a 100-120 grit. With a good smoothing plane, you can even get away without sanding.
