After a few years of using a quarter sheet vibrating sander, I wanted to step up to a random orbital sander. After evaluating the various random orbital sanders I settled on the DeWalt DW421. The DeWalt DW421 uses 5”, eight hole hook and loop sanding disks.
Overall the sander is solidly built with a good fit and finish. It provides a very smooth operation with minimal noise level and vibration. The sander weights in, by my scale, around 3 pounds. The palm grip of the sander has a good comfortable feel to it. The motor is strong and durable. The orbiting sanding pad is made of thick high quality rubber with hook and loop facing. It comes with a 6 foot long, 18 AWG double insulated electric cord that is securely attached to the sander. I have accidentally tested this more than once.
The real test of a random orbital sander is how well does it work and how hard is it on me? The sander is balanced very well. When running it feels comfortable in my hand with minimal vibration. The sander is heavy enough to sand with its own weight, all that is necessary is to guide it to where you want it to sand.
Tip: Random orbital sanders work best with minimal pressure. If you press down too hard it can cause the orbiting pad to slow down or stop orbiting. So, use as little pressure as needed to get the sander to sand.
I have found that I was able to work on horizontal, vertical and overhead surfaces with equal ease and minimal fatigue.
The biggest disadvantage is the dust collection system. It is designed with a highly touted ‘Controlled Finishing System’ which is basically a small dust collection bag attached to the rear of the sander. The bag works ok in collecting dust. However, the sander still kicks out a fair amount of dust while sanding. So be cautioned, always wear safety goggles and a respirator when operating this tool!
Removing the dust collection bag exposes a dust collection port that you can hook up to a shop vac or dust collector. The design is for the hose to slip over the dust collection port. There is no locking feature to keep the hose connected, so there is a pretty good chance that the hose will slip off during use.
My other frustration is the CFS gasket. This is a large gasket that fits between the sander’s orbital pad and the body. Gasket tends to wear out rather easily, why did they choose to skimp on this component I don’t know. The easiest way to determine if the gasket is worn out, besides a larger that normal cloud of dust when sanding, is orbiting pad’s rotation would accelerate dramatically when not in contact with any surface. An addendum to the owner’s manual attests to this being due to the gasket being worn out.
Replacing the gasket is a fairly straight forward procedure: remove the orbiting pad (held in place with three screws), remove the old gasket and put in the new one, reinstall the orbiting pad. The whole procedure took about fifteen minutes. The gaskets are fairly pricey at $7 each!
Even with these issues, I am very pleased with the DeWalt Random Orbital Palm Sander DW421 and recommend anyone looking to add a random orbital sander to consider this one.
