There are many different types of sanders, but for cabinet doors, you're most likely looking at one of these options: Random orbital sander:The random orbital sander is one of the most popular and versatile sanders. They offer the perfect middle ground between more aggressive sanders and refined finishing sanders.
Sand your cabinets
You can sand by hand if you like, but your arms will probably get pretty tired. Painted cabinets should get a thorough sanding with 120-grit paper, but no matter the finish, do a final pass with 220-grit.
We asked four woodworkers and four home improvement editors the same question: “What is the best sander to buy for finishing cabinets”. And we got a unanimous response: “Buy a random orbital sander.” All in all, there's really nothing “wrong” with square-based, orbital finishing sanders.
In comparison to palm sanders, orbital sanders can remove material more quickly. Compared to palm sanders, orbital sanders will also remove more material. Although both sanders are regarded as being mild, the orbital sander in this comparison is more potent and will still remove more material than palm sanders.
If you are only going to buy ONE sander, I would say the random orbital is your best option since it goes from course to fine sanding easily. If you are doing a lot of fine finishing work and want to save some money (and not have to lift such a heavy sander) then a finishing sander is worth the small investment.
A survey of four woodworkers and four home-improvement editors in “The Family Handyman” yielded the unanimous answer that a random orbital sander works best for finishing cabinets.
Start with coarse 80-grit sandpaper in a manual hand sander or power sander. Using enough pressure to remove the paint but not so much that it damages the wood. Move to medium 150-grit abrasive and finish with fine 220-grit, brushing away dust from the surface each time you change paper.
You should sand cabinets before beginning your how to paint kitchen cabinet project to give the new paint a good surface to grip. But you don't need to sand to bare wood.
Clean– lastly, after sanding, you'll give your cabinets one final cleaning. No need to degrease, just a good wipe down to ensure you have removed all the dust and small particles. If you're working outside, I love to use my leaf blower for this, followed by wiping with a tack cloth.
Follow the directions on the liquid sander or liquid deglosser you're using. Dip the scouring pad in the liquid sander and gently scrub the cabinets in the direction of the grain. Wipe off all of the liquid sander with a wet rag. Wipe the cabinets again with a clean rag.
There are two distinct differences, however. While regular sheet-stock or quarter-sheet sanders sand in a predictable orbiting pattern, random orbital sanders oscillate in a non-predictable or random motion.
Sand Cabinets to Prepare for Painting
Use a fine-grit sandpaper and sand until the wood is smooth to the touch. Use a shop vac to remove any visible dust. Then, be sure to wipe away any remaining dust or debris with a clean cloth before moving on to the next step.
In general, it's best to sand with the grain of the wood, especially for the final grits. But to remove deep scratches and stains, it's OK to angle across the grain, up to about 45 degrees for the initial sanding. This goes contrary to popular opinion, but it's a good method to remove material quickly.
Random-Orbit Sander: This is one of the most versatile sanders. Disc and orbital sanders provide a super-fine finish to surfaces and feature a built-in ventilation system that prevents dust from scattering all over the room.
Besides operating at no less than 90 PSI of air pressure, random orbital sanders should run with a minimum speed of 10,000 RPM. If you run the sander at a slower speed than this, swirl marks MAY also appear. But if you drop below 90 PSI at any time during your orbital sanding process, you WILL get swirl marks.
Well the simple fact is that hand sanding has many benefits over power sanding that can often be overlooked. Firstly, a final hand sand before finishing will always give a better finish than ending with a power sander as, no matter how fine a grit you use, there will always be scratch marks left by the power tool.