I use Dewalt random orbital sanders regularly while I construct rustic log furniture. After a couple of years of use sanding the curved surfaces of logs, the hook and loop sanding disks no longer adhere to the sanding pad. What can I do to address this problem? The sanders are dewalt models D 26451 and DW 421

yes as long as it is the same type of disc, e.g. hook and loop or psa.

Impossible not to get water in the bearings and motor. It is vibrating too fast. You need air sander. Or sand dry, then wet sand the primer by hand.

I think your model holds the paper with glue that is on the sand paper.Just take apart the back cover of the sand paper to expose the glue.

I have the same problem with a Porter Cable orbital sander I recently purchased. Whats happening is the sander is catching the edge of the board you're trying to sand and jerking back and forth as the sander base spins. It seems that if the board your're sanding is at least as wide as the sander base, the problem goes away, which does little good because there will be many times I we'll need to sand wood that is less in size. But you may try using a lesser grit sandpaper and see if that alleviates the problem somewhat.

remove pad and clean and lube cam

Seems time for a new sander.

This info may help;

Features: DeWalt D26451K 5" Random Orbit Sander Kit

• 3.0 Amp motor operates at 12,000 opm providing ideal sanding speed for smooth finish
• Textured anti-slip top & body grip provides ultimate comfort and control during prolonged use
• Controlled Finishing System maintains pad speed and minimizes gouging during start up
• Dust-sealed switch prevents contamination
• Sealed 100 percent ball-bearing construction provides longer life
• High capacity dust bag with built in vacuum adapter provides maximum dust collection with or without vacuum
• Dual-plane counter-balanced fan reduces user fatigue
• Accepts 5", 8-hole hook & loop paper allows sanding discs to be switched back and forth quickly and easily
• The sanding discs mate to the sander plate similar to Velcro, and this particular sander uses a 5" disc with 8 holes in it. Can be purchased in Home Depot, Lowes, etc....

Hope this helps!

Never start the Sander without first placing it against the surface to be sanded. In free air the Sander will not osolate.

Just solved my problem with Porter Cable 333 orbital sander which just groaned. I thought the worst. I carefully took it apart on the garage floor and immediately suspected it needed lubrication as the motor turned hard. I used my flexible long plastic tube lubrication and put some on the bottom bearing shaft the best I could. I worked it around and around. I began to feel it turning easier. I applied more oil and kept moving and it became completely free. I put a drop on the top bearing even though it was loose. I put it all back together and it works like new. Lesson: do not look for the worst when a tool quits. Suspect the culprit to be lack of lubrication!!!

You will find usually 3 torx drive screws on the bottom of the tool, remove them and the pad comes off. The replacement pad number is 151416-01 list 27.49. Let me know if I can help further