‘Sandpaper’ – the commonly known product made up with paper backing or cloth material, is mostly required in home improvement. Silicon carbide and aluminium oxide are the major impregnating abrasive particles of sandpaper. Other than being an active member of the home repair activities, it’s equally effective in smoothing and cleaning metals and woods while painting or finishing.
Choosing the right sandpaper grits is the trickiest part of making use of the sandpaper. As per the abrasive particles’ coarseness, there are different categories of sandpaper grits. In order to paint or work on finishing, you need to prepare the surface first. In that case, you need to make use of the finest grits in handing the surface repetitively until it gets the ultimate smoothness.
The surface gets extremely rough for finishing before finishing and painting, so sanding detailed work on an item of furniture gets easier if the sandpaper is extra coarse. On the other hand, sandpaper, which is extra smooth, requires a lot more effort while sanding for attaining exactly what you want. Therefore, the right choice of sandpaper grits is an essential factor for extracting the maximum utility out of it.
The Numbering of Grits
There are separate gauge numbers of different grits depending upon their size. As the number gets lower, the grit gets significantly coarser and larger. For example, 1000-grit sandpaper contains comparatively smaller abrasive particles and is finer than the 25- or 50-grit sandpapers that are more coarse.
Once you check on the backside of sandpaper, you’ll find the grit number reflecting. From 24 to 1000, there is a wide variety of grit numbers available in the queue. Hopefully, you’ve realized already that using lower grit sandpaper is always more beneficial than purchasing the higher ones on the scale.
In the screens, the holes per square inch number basically decide the scale numbers. While manufacturing sandpaper, it is used to sieve the abrasive grains. As an instance, a screen with 60 holes per square inch can sieve the sandpaper’s abrasive particles in 60-grit sandpaper.
How Does a Grit Matter?
With much less effort, you can sand any materials or woods faster with a lower-grit and coarser sandpaper than the finer sandpapers. On the surface of the material, it cuts off the fibers and helps in completing the work faster. While you’re trying to eliminate old blemishes or paint, remove a bulk of materials or shape and edge, aggressive scratching is all you need. However, there are possibilities of leaving deep scratches in the wake due to aggressive sanding. Therefore, you must be careful enough not to destroy your project in the end.
On the other side of the page, only small particles can be eradicated with fine sandpapers while leaving a soothing effect on the surface. The don’t surface gets more polished with a finer sandpaper grit. The only trouble you need to bear by choosing higher-grit fine sandpaper is putting a lot of your time and effort into the project for attaining the best results.
Remember, too-much sanding with extra smooth sandpaper can deliberately result in surface burning and creation of extra-worked portions where absorption of other finishes and stains can be hindered. Thus when finished and stained completely, the extra-sanded wood portrays a blotchy appearance.
So what’s the trick to get done with your work at the earliest? Begin with choosing coarser and lower-grit sandpaper for detailing the work as soon as possible. And then progressively elevate to the less coarse and higher-grit sandpapers to smoothen the surface and get the finished product. So this way, you attain your goals easily with a smarter approach to choosing the sandpaper grits.
On purchasing different types of sandpaper grits, you should closely observe them. In between the abrasive grains, you may find holes in between the abrasive grains. These spaces are commonly known as an open coat, and it creates a place for the scarf to pass.
Glasses and steel have smaller swarf particles. However, while sanding a wood, these open coats are extremely important as the swarf particles are comparatively bigger in this case. These spaces allow swarf substances to pass and prevent pore-clogging.
A quick sandpaper fact: An increased variability degree is quite common in some of the sandpaper types. This clearly indicates that by applying pressure and heat, these abrasive grains do fragment. This procedure is helpful in enabling sandpaper renewal and sharp-edge creation. More friable sandpapers are more long-lasting than the rest.
Ranging The Grits
Mostly, there are four major types of grits: garnet, ceramic, aluminium oxide, and silicon carbide. As aluminium oxide is rich in self-renewing properties, its impacts is comparatively longer-lasting than the rest. While forming fresh, delicate edges, it crumbles efficiently and acts softly. Garnet is used for attaining the smoothest and the fastest surface. In order to sand tough materials like plastic or metal, silicon carbide works pretty well. Finally, the most expensive one is ceramic, which is again one of the roughest sandpaper grit, which is mainly required in wood-shaping.
As a matter of fact, there is an end number of sandpaper grades available in the market. However, these are the highly appreciated and commonly-called grit ranges that you must try out:
#60-#80 (comparatively coarser)
Sandpaper grits ranging in between the numbers can effortlessly cut through rough edges or old paints. These are also great for rounding and shaping up the edges. In case you wish to sharpen the corners or edges or try to get a detailed work out of these sandpapers, it will turn into a complete waste of time. Keep in mind that plywood is very easy to cut through, so you have to be very cautious while sanding with lower-grit sandpaper.
#100-#150 (medium coarse)
These sandpaper gauges are most frequently used. Sandpaper grits ranging in between 100-150, hardly causes chaos in its work. All you have to do is put more pressure on the piece of work and bring down even the most difficult projects. Otherwise, you can also choose to let the pressure up and store fine materials. In order to work on a bare wood surface, these sandpapers are truly useful. After completing the paint, experts recommend a final sanding with 150-grit sandpaper. In order to grip onto the finishing, the range of sandpapers end-up with a tiny “tooth” to the surface. Remember, for yielding a finer finish, sanding extra doesn’t really work.
Note: To attain superior glossy finishes, the range doesn’t apply. In that case, using fine sandpapers is essential to sand between the coats of the paint.
#180-#220 (fine grits)
To begin with, sanding paint or finish, this range is seldom applicable. It only works on an already smooth surface. For record or third level sanding, these grits are quite useful. Before the application of another paint coat, these sandpapers are used for roughening a shiny paint. Using higher sandpaper than 220-grit should not be applicable to bare wood sanding.
#320 and beyond (ultra-fine grits)
In order to achieve the ultimate smoothness, this sandpaper range is extremely efficient on any type of material. In order to sand between the coats of a painted surface, these ultra-fine grits work great on woods. During wet sanding, several ultra-fine grits are used for attaining a gritty, fine slurry outcome that decides the worth of the sandpaper’s efficiency in smoothing.
How Do You Choose The Right Sandpaper Type And Grit?
There are different job roles for separate sandpaper grits, and the trickiest part is choosing the appropriate ones for your DIY project. However, nothing to worry about, as I’m here to provide you with a perfect guide with essential thumb rules of choosing the most suitable grits. So let’s run through it…
Size of The Sandpaper Grit
It’s quite obvious that sandpapers aren’t made of sand. Instead, it carries natural- or synthetic-sourced fine particles. The particles are commonly known as grits or grains. One has to screen and sort these particles beforehand and then creates a bond with adhesive to a cloth-type material, sponge, or paper. And finally, it creates the finished abrasive material called sandpaper that’s pretty much handy for several do-it-yourself projects. As each project has different requirements, separating the sizes of sandpaper, grits is the foremost essential factor.
In the United States of America, the Coated Abrasive Manufacturers Institute (CAMI) introduced a gradation scale that determines the sandpaper grit. You can see a different range of sandpaper grits mentioned at the backside of the sandpapers. Before you choose one, always remember:
- A higher-grit newspaper contains finer sandpaper particles and smaller grains.
- Whereas, lower-grit sandpaper refers to a coarser effect along with larger particles.
The measurement unit of a sandpaper grit is micron as per the CAMI scale. In that case, checking out 100-grit sandpaper can assist you in understanding the exact size of a micron. 141 micron is the approximate size of the small grains of sandpaper. The number is equivalent to .00550 of an inch, which is excessively tiny.
At the lumber yards or the DIY centers, the usual go-to places for buying sandpapers, do use CAMI scale for its measurements. However, if you’ve ordered it online, they usually follow the size chart established by the Federation of European Producers of Abrasives (FEPA). Here, the letter “P” refers to the grit unit preceding the number of the grit.
In fact, there is an end number of grit gradations available in different corners. Nevertheless, you can certainly study the CAMI sizes minutely even while purchasing FEPA graded sandpapers. Thus you get the basic idea of sizing the sandpaper grits and determine their efficiency in your work. On the other hand, at the initial stage, choosing a few closest FEPA-scaled grits can also be a great option to determine the differences.
- 40-grit (CAMI) sandpaper approximately equivalent to (FEPA) P-36 or P-40
- 80-grit (CAMI) sandpaper approximately equivalent to (FEPA) P-80 or F-100
- 100-grit (CAMI) sandpaper approximately equivalent to (FEPA) P-100 or P-120
- 120-grit (CAMI) sandpaper approximately equivalent to (FEPA) P-120 or P-150
- 220-grit (CAMI) sandpaper approximately equivalent to (FEPA) P-180 or P-220
- 400-grit (CAMI) sandpaper approximately equivalent to (FEPA) P-600 or P-800
Picking The Appropriate Coarseness
Along with the exact grade of the sandpaper grit, manufacturers do mention the level of coarseness in vibrant words in order to simplify the choice for the newbies. The words clearly elaborate a whole range of sandpaper grits almost equally impactful for the specific sanding project. Additionally, it’s pretty much common for sanding work to decide on the coarseness level while opposing an exact sandpaper grit. Therefore, knowing the involvement of each level is a smart work to conduct beforehand.
- Ranging in between the 24- to 36-grit sandpapers are quite difficult to deal with. Usually, for eliminating extra stubborn paint, these sandpapers are mostly used. Similarly, the extra-coarse sandpaper’ abrasiveness is required for old floor sanding. Remember, this shouldn’t be implemented in the most difficult jobs.
- In order to eradicate the older finishes and shape up the woods, the range of 40- to 50-grit sandpapers are great choices. For polyurethanes light coats sanding, these sandpaper grits work well.
- You can use the sandpapers ranging between 60- to 100-grits for the final shaping-up procedure. This specific range of sandpapers are highly recommended for removing the planning mark from the wood after finishing off the rough wood sanding.
- The sandpapers ranging between 120- to 220-grit are quite efficient for conducting home workshops successfully. The job role of this range is to suffice the finished paint before getting it done with the final sanding.
- In between the varnish and the coats of paint, this extra-fine sandpaper is mostly suggested. During high-end polishing, the sandpaper grits reaching up to 600 are the best-qualified ones. However, 240-, 320- and 400-grit sandpapers are also considered to be the fine ones.
Note: While conducting some specific projects, a lower-grit, coarse sandpapers should be your first choice, and then you move ahead to make use of the higher-grit, finer sandpaper to polish the surface efficiently.
Choice of The Grit Material
Apart from the sandpaper grit density, the abrasive material type of a sandpaper grit also contributes largely to your sanding project success. For sand and smooth material types, there are some typical grit grains best effective to the project—for example – wood versus metal. Before you shop, though the manufacturers do mention the best-suited material types for sanding, you must have an in-depth knowledge of the exact grit-type you should be working on.
Flint: For old paint or varnish and other surface products sanding, flint is the most effective material. It is a durable and completely natural grain.
Emery: Mostly for polishing metals like steel and eradicating corrosion, this specific type of material works well. It’s natural, and the particle edges are sharp enough to sand wood-like surfaces.
Garnet: In sanding metals, garnet seems to dull the surface comparatively quicker than emery and flint. It is relatively softer and is a completely natural grain, which is highly recommended to work on smoothing and sanding of wood.
Aluminium oxide: For polishing and sanding different forms of metals, like – alloy steel and metal, aluminium oxide is one of the best products to make use of. Other than that, this synthetic durable grit is amazing for hardwoods sanding.
Zirconia alumina: In order to work on rough wood sanding initially and swipe away metal burrs, zirconia alumina is a wonderful product. The grit is synthetic and very long-lasting. You would hardly require replacing the sandpaper if you’re using zirconia alumina for sanding metal, as the grit substances get sharper with every move.
Silicon carbide: Among all the synthetic abrasives, silicon carbide is the most durable one. In order to sand metal, softwoods, hardwoods, plastic, and a variety of materials, silicon carbide should be the best choice.
Picking The Appropriate Sanding Tool
As per the nature of sandpaper, it’s extremely versatile on its own. All you have to do is sand the grit constantly to dull it after folding the sheet into a small square that fits in your palm. In order to start sanding on a fresh surface, you have to refold the sheet once again. Purchasing more than one sanding tool might be helpful if you have a bulk of materials to sand. Remember, picking the most appropriate equipment, doesn’t wipe away the importance of choosing the exact type of sandpaper during a project.
Manual Hand Sander: A handle for the users to move the equipment smoothly in no time, side clamps for ensuring the sandpaper security, a pad, and the rubber surface are the basic features of a manual hand sander. For sanding the sides of a bookshelf or other wide area sanding, the tool works great with a folded piece of sandpaper.
Vibrating Palm Sander: you’re absolutely free to pick any of the variety-shaped sanding plates, for example – to open sand surfaces, choose rectangular or square, for hard-to-reach spots, choose a triangular one while sanding with the corded power sander which easily fits in one hand. Remember, certain palm sanders only allow pre-designed sanding pads. Therefore, just swipe the switch in after attaching the sandpaper onto it and let the vibrations take care of the entire sanding job with your guidance.
Sponge sanding: For sanding oval-shaped edges evenly, all you have to do is, press the sponge on the oval surface. A sanding sponge is supple in nature, and it’s covered by sanding grit with a flexible piece of sponge inside. The right spots like stair balusters’ base, can be sanded effortlessly with the beveled-sized sponge. Moreover, working with a sponge while sanding is comfortable and easy.
Belt sander: The belt sander requires you to use both your hands to work with the band-help sander, which contains a huge amount of sanding power. At the surface of the sander, there are two cylindrical drums fitted below the pre-packaged sanding loops. As soon as you power on the sander, the belt of the sander works in a specific direction, and the drums start spinning. As the belt works in one specific direction, you must take the lead and keep the sander working till the work is finished. In order to sand in large rough areas or eliminate old varnish, the belt sander does a good job. There is a possibility of leaving visible and deep sanding scars if the sander is worked in one direction only.
Drum sander: A huge cylinder accommodating a large sanding loop or belt is the basic structure of a drum sander. As soon as switching on the sander, it works exactly the same way as a belt sander, and the drum keeps spinning. In fact, similar to the belt sander, a drum sander should also be directed to different positions in order to avoid leaving sanding scars on the surface.
Floor Sanders: Drums, large belts, and other orbital sanding plates are the basic features of a floor sander. It’s highly efficient for hardwood flooring, eradicating the previous varnish and grinding or flooring warped wood. In order to avoid uncertain floor scarring or damages, one has to take part in the operations to direct it even though the machine is powerful enough.
Orbital sander: This particular sander works in an orbital or circular pattern just like its name suggests, and this shouldn’t turn to spin. Just like you move your hand in a clockwise or anti-clock motion on a flat surface, the job of an orbital wander resembles the same. Pre-cut sanding pads on an orbital sander are good for flat-surfaces-sanding. Similarly, the regular sander cut-pieces are also accepted by the orbital sander according to its brand and size.
Random orbital sander: Similar to the orbital sander, the random orbital sander also works in an orbital pattern. The interesting part is, while sanding with a random orbital sander, the sanding base also keeps moving in a back-and-forth and side-to-side motion. Holding the sander constantly at one place leaves a few sanding marks on the surface. However, this particular sanding procedure completely swipes away the possibility of scarring the surface. This specific sander type only accepts pre-cut sanding plates, which should be circular in shape.
Bench-mounted sanders: Mostly for minimum woodworking jobs, this sander type is the best-suited choice. It mounts to your workbench permanently. Bench-mounted sanders sands, spins and vibrates as per their drum and belt choice and incorporates any of the methods to work efficiently. Remember, you have to keep moving the wooden surface on your own while operating a bench-mounted sander.
Powerful Debris Removal Tools
As you have to keep replacing the sandpaper grit numbers in order to conduct different tasks on a workpiece, you must clean off the dust extracted by the previous sanding. Otherwise, the debris can clog the pores and create obstacles for the next sandpaper grit to work efficiently.
Tack cloth: Wiping off the dust from the surface with a wet cloth is the traditional process of cleaning the pores. However, in this process, there is a possibility of getting the workpiece tougher to stain by increasing the wood substances. Thankfully, tack cloth is a cheesecloth that is sticky enough to pick the dust deep within the pores.
Zinc Stearate coating: A soapy surface of sandpaper is the most appropriate form to avoid pore-clogging. If you’re working on a water-base finish, it would require less maintenance, and this tool should be applicable to get the best results.
Tips for Working with Sandpaper and Other Abrasives
With the right tactics and brainstorming, a successful project can easily be created. In the above sections, I’ve mentioned how you can choose an appropriate sandpaper grit and work with the accurate sandpaper tool. Now here comes the time when I would be sharing a few effective tips to give your project the ultimate finishing.
So let’s have a look…
- Choose the surfaces where it is slightly less visible to determine how a sanding tool and abrasive particles eradicate the material—for example, scrap wood.
- Follow the accurate sequence and sand the surface with the finest-grit sandpaper. Some people choose to skip grit numbers and start working on the next. However, let me tell you that it’s even more time consuming to get accustomed to the next piece of sandpaper.
- Hand sanding requires a comparatively higher pace than power sanding. Especially, while sanding woods, working at a faster pace can leave deep scratches on the surface.
- Never put too much pressure on a power sander. Extreme pressure from the electric sander results in less efficiency in material removal and poor finishing. Therefore, let the sandpaper and the tool work on their own with your minimum guidance. Always replace the sandpaper in case you don’t attain your desired results with a light touch.
- Before you start working with a fresh sandpaper grit, always clean off the loose abrasives and dust remaining on the workpiece. You can simply wipe the dust off or vacuum the surface.
- In order to avoid pore-clogging, always pick wood’s grain for sanding. You have to take repetitive actions to sand correctly, so you have to be more calm and patient. At first, you must begin with coarse sandpaper and then move your way up progressively to finer papers.
- In order to eliminate bigger imperfections, coarser grits are the best suitable ones. Whereas, for small-to-moderate flawed surfaces, the medium-grit sandpapers work better.
- In most of the cases, you must use a 150- to 200-grit sandpaper to complete the final sanding. However, to touch up things, you must sand it again with a 220-grit paper. As I mentioned before, the debris created after the previous sanding can create obstacles for the next smoothing process, so always clear off the dust before starting fresh.
- While working on metals like brass, you must make use of the higher-grit sandpapers. And remember not to put too much pressure and let the sander do the work.
Hopefully, I’ve covered all the nooks and corners of different sandpaper grits and their workarounds. Starting from identifying the different types of sandpaper grits to the procedure of sanding, everything should seem pretty clear to you. So decide on your next project essentials and get set go!