Sanding drywall by hand can be a tedious task. Naturally, you may opt to use a powered sander to expedite and simplify the process. Take the orbital sander, for example: Can you use it on drywall without any concerns?
You can use an orbital sander on drywall. A random orbital sander is better than a traditional one with a small range and does not oscillate. Consider connecting a random orbital sander to a vac with an adapter and a hose to collect dust.
A traditional orbital sander is a manual power tool that can leave swirl marks when you use it on drywall. On the other hand, a random orbital sander doesn’t have this problem unless you use it incorrectly. This article will discuss how to use these tools on drywall.
How To Sand Drywall With an Orbital Sander
Orbital sanders are only suitable for dry sanding. Neither a classic orbital nor a random orbital sander will work for wet sanding. In fact, you can only manually sand drywall with a sanding sheet or sandpaper if the joint compound or mud is dry. You should use drywall sponges for wet sanding.
Here’s a step-by-step guide to help you sand drywall with an orbital sander:
1. Select the Right Type of Orbital Sander
Not only do you need the correct type of orbital sander, but you also require the right size depending on the scale of your project. Also, you must be familiar with an orbital sander’s orbit size and rotational speed or rpm. Contemporary random orbital sanders have a variable speed setting.
You must choose the most appropriate features in an orbital sander to sand drywall, such as:
- Type: Random orbital sander is better than a conventional orbital sander because it uses oscillation and spinning simultaneously to create truly randomized orbits that won’t leave swirl marks and other traces on your drywall.
- Size: Typically, 5-inch or 6-inch (127 mm or 152.4 mm) sandpaper diameter for random orbital sanders, and 1/4 or 1/2 of the standard 9 inches x 11 inches (22.8 cm x 27.9 cm) sandpaper sheet for orbital sanders with a rectangular or square pad or plate.
- Orbit: 3/32 of an inch (~2.4 mm) is better for fine finishing than 3/8 and 3/16 of an inch (~9.5 mm and ~4.75 mm).
A 6-inch (152.4 mm) random orbital sander will be more convenient than a 5-inch (127 mm) sanding disc. Likewise, if you have an orbital sander, one that can use 1/2 of a standard sanding sheet will cover more area and be faster than a 1/4 rectangle or square-shaped plate.
That said, a smaller sanding area may be desirable when you focus on corners and edges. Therefore, assess your project’s needs and choose accordingly. The same approach should apply to selecting the right orbit of such sanders to sand drywall.
The 3M Elite Random Orbital Sander 28582 (available on Amazon.com) has a 3/8-inch (~9.5 mm) orbit. This model is more suitable for coarse sanding. You should use low-grit sandpaper for drywall sanding using a random or traditional orbital sander.
The same 3M Elite series has the 3M Random Orbital Sander 28517 model (available on Amazon.com) with a 3/32-inch (~2.4 mm) orbit. This sander has the identical 6-inch (15.24 cm) sanding disc backing pad and 10,000 rpm as the 28582. This 28517 model with a suitable orbit comes with a self-generated vacuum bag.
2. Choose an Appropriate Sandpaper Grit
Most people use fine-grit sandpaper to sand drywall, usually 160 and above. You may go up to 220 if you are unsure about the sanding effect using an orbital sander. Both random and regular orbital sanders will likely be more effective than manual sanding, so stay with fine grits.
Some parts of drywall may have more compound, and a very fine grit might not be effective or efficient. However, you will probably not need anything below 150 to sand drywall with an orbital sander. Ensure the sanding disc is fastened correctly, or it may fly off a random orbital sander.
3. Connect a Shop Vac for Dust Collection
Dry sanding will inevitably lead to a lot of dust buildup on your drywall. The entire room (and, in some cases, other areas of your house) may also have excess dust. Therefore, you must use some kind of dust collection system.
The 3M 28517 model above has a vacuum bag, and so do the likes of the Black & Decker Random Orbit Sander (available on Amazon.com) and DEWALT 20V MAX Orbital Sander (available on Amazon.com). But you need more than these dust collection bags to continue sanding an entire drywall and another.
Ideally, you should connect a shop vac and a hose to the dust collection port of orbital sanders, or you can get a dust collector, like the DEWALT Dust Extractor with Automatic Filter (available on Amazon.com). This model has a 10-gallon (37.8 liters) capacity. It is also lightweight and has a telescoping handle, making it easy to move around.
Most orbital sanders need an adapter to attach a vacuum to their ports. For instance, a typical 1.25-inch (31.75 mm) hose requires a DEWALT Universal Quick Connector (available on Amazon.com) for Dewalt’s orbital sanders. This connector works for standard vacs and various Dewalt tools.
Likewise, the Black & Decker 58756100 Vacuum Adaptor and Black & Decker 58784300 Vacuum Adaptor (available on Amazon.com) are two distinct parts for different ports in the company’s random orbital sanders. If you have one of these models, match the part number and get either adaptor for your vacuum.
If you own a Bosch orbital sander, you may need its Bosch VAC002 Vacuum Hose Adapter (available on Amazon.com). You can use this adapter’s internal and external diameters for 1.25-inch (31.75 mm) and 1.5-inch (38.1 mm) vacuum hoses.
Remember, you can use an orbital sander without a dust collection system. However, you will need to take the following precautions in such a scenario:
- You must seal the doors, gaps, and seams to other rooms.
- You must cover registers and vents with plastic or tape them.
- You must have at least one fully open window in the room.
- You must use protective eyewear and a mask or respirator.
- You must wear appropriate clothes and gloves for the job.
Old orbital sanders using rectangular or square sanding sheets require you to make holes in the sandpaper so that a dust collection system can work. Otherwise, there will be no point in using a dust collector or a vac. The sanding discs for random orbital sanders typically have premade holes.
4. Check if Drywall Is Ready for Sanding
Your drywall should be bone-dry before you sand it with orbital sanders. Otherwise, powered sanding may cause gouging, which can be a serious issue if your drywall’s condition is poor. Moist drywall may also dry too quickly due to orbital sanders, causing crumbling.
Using an orbital sander will generate heat due to the friction of the sanding sheet or sandpaper, which can cause unusually faster drying of drywall compound. The material will likely crack, and your drywall may have other structural and visible damage.
5. Use the Orbital Sander Flat on Drywall
Both random and regular orbital sanders should lay absolutely flat on your drywall. The classic design with its rectangular or square plate may not lift or tilt easily. However, random orbital sanders with their lighter weights and smaller circular sizes may lift off or tilt on your drywall.
You don’t need to exert much force with either type of orbital sander. However, ensure that the entire sanding disc or sheet is even and flat on the drywall surface throughout the process. You should be more careful at the edges and seams when orbital sanders may not stay flat naturally.
6. Apply Minimal Pressure While Sanding
Don’t press an orbital sander against drywall. Allow the sander’s orbiting action and sandpaper to do the work. The minimal pressure you need to apply is solely to hold an orbital sander firmly in place and operate it as required. Exercise more caution over the following areas and fixtures:
7. Sand With Gentle and Smooth Motions
Random and regular orbital sanders operate in different ways. You need to use different motions for each of them. A regular orbital sander requires a linear motion, which may be:
You don’t need to maintain a perfectly straight line or impeccable linear motion, but you can’t go for a circular pattern. The rectangular or square backing pad or plate is unsuitable for a circular motion.
In contrast, random orbital sanders require a constant circular movement. You can opt for clockwise or anticlockwise circular motions.
Stay consistent with what you select for the entire drywall area. Also, you need to move both types of orbital sanders constantly. The difference lies in circular and linear motions. The motions must be gentle and smooth with both.
8. Review the Progress To Make Changes
You may have to switch from one grit to another, depending on problems, if any, and the desired progress. A random orbital sander may have a more uniform sanding effect due to the tool’s combined orbiting and oscillating actions. Regular orbital sanders may require a bit more effort.
When the compound is fully dry, you can use a random or regular orbital sander on drywall. Also, a dust collection system or hooking up your vac and hose with an adapter is a much better way to sand drywall instead of allowing the dry, tiny particles to fly all around and create a mess.