Columns - The SandPaper (2024)

FAQs

Is the lower the number the rougher the sandpaper? ›

The grit of sandpapers is a rating of the size of abrasive materials on the sandpaper. The higher grit number is equivalent to a finer abrasive, which creates smoother surface finishes. Lower grit numbers represent coarser abrasives that scrape off materials much quicker.

The higher the grit number, the finer the abrasive particles and the smoother the finish that can be achieved. The lower the grit number, the coarser the finish but quicker the material removal rate. The grit you opt for completely depends on your application.

Grain Direction

You can use your fingernail against the wood to determine the direction of the grain, if your nail catches, you know that you are moving against the grain so you should plane the other way, with the grain.

Always start with a coarse grit belt or disc and work your way progressively through finer and finer grits until you reach the desired level of smoothness. Don't press down too hard or you'll clog up the abrasive disc or belt; let the weight of the tool provide the right amount of pressure.

For example, if you're refinishing a piece of wood furniture, you'll start with a coarse grit like 80 to remove the finish and smooth any imperfections. Next, you'll advance to a finer grit like 100 or 120 to smooth the scratches left behind by the 80-grit sandpaper.

Very-fine (150-, 180- and 220-grit): This produces ultra-smooth surfaces on wood. People often use it to scuff-sand lacquer, polyurethane and other finishes before applying another coat. Extra-fine (320- and 360-grit): The first of the micro-abrasives, this is primarily for sanding finishes before polishing.

That one thing is Never Skip More Than One Grit. If you are confused by this, you can go from 100 grit to 150 grit (skipping 120 grit), but you cannot go from 100 grit to 180 grit (which would be skipping two grits – 100 and 120).

Generally speaking, you'll want to use coarse grits (P8 - P80) for stock removal and the stripping of paints and varnishes. You'll then want to use medium grits (P100 - P220) for prepping and shaping materials followed by fine grits (P240+) for sharpening and polishing.

circular motion when sanding will sand both grains evenly. If you sand with the grain for one, and cross-grain for the other, they won't sand evenly. And as Evensd2 says, once you get to the really fine grit, it doesn't matter much.

How do you sand wood without losing the grain? ›

Sanding with the grain is the golden rule of woodworking, which means moving the sandpaper in the same direction as the wood grain. It helps to minimize visible scratches and results in a smoother, more professional-looking finish. It's not always clearly visible which way the grain runs on some types of wood.

To know when you are done sanding, look at the wood in a low-angle reflected light. Or wet the wood then look at it from different angles. Before you apply your finish, raise the grain by wiping the surface with water. Then sand lightly to remove the nubs from the raised grain.

The golden rule of sanding is to start with a grit coarse enough to quickly remove surface imperfections and follow with incrementally finer grits. Each successive grit erases the scratches of the coarser one before, until the scratches themselves become undetectable to the eye and the touch.

The Golden Rule of Sanding

So, what to do if you need to rough sand all the way on through to the finer grits for finishing? The golden rule for choosing your sequence is to never skip more than 1 grit.

What does the P mean in sandpaper grits? Sandpaper grit in the UK and Europe is graded by FEPA (Federation of European Producers of Abrasives). This is represented on the back of a sheet of sandpaper with the letter P e.g. P180, P60, P240. The scale is based on the diameter of the average particle size in microns.

Choosing the Right Sandpaper Grit

For heavy sanding and stripping, you need coarse sandpaper grit measuring 40- to 60-grit; for smoothing surfaces and removing small imperfections, choose medium sandpaper from 80- to 120-grit sandpaper. To finish surfaces smoothly, use a super fine sandpaper with 400- to 600-grit.

Fine Sandpaper, ranging from 120- to 220-grit, is used in most home workshops. This sandpaper is often used for final sanding before a project is completed. Extra-fine Sandpaper, including paper with 240-grit to 600-grit, is used between paintings or varnishing and is best suited for polishing jobs.

Extra fine sandpaper

This is 240 grit and above. The common choice amongst DIYers is 240 grit, which is used between coats to smooth the previous layer of paint ready for the next to help ensure a smooth finish. Higher grit sandpaper such as 320 grit will provide an even smoother finish between coats.