Are these sanding discs defective?

Question

This is the first sandpaper disc I put on my new sander earlier today. The front is not even starting to wear out but as you can see the loop fabric on the back is trashed and it won't stick to the sander anymore.

I don't push very hard and always let up if the sander starts to slow down. The hooks aren't melted.

I paid $15 for the Tacklife sander and 12 discs from walmart.com. Am I doing something wrong or do I just need higher quality pads?

Answer 1

To confirm, is that the pad (the squishy part that attaches to the sander and has Velcro to attach a sanding disk to) or the disk itself (the Velcro-backed replaceable disk with grit material)?

In either case, you've got a cheap sander and, I'm sure, cheap sanding disks. The pad on the cheap sander will wear out much more quickly than it will on a quality sander. Cheap disks will also wear out/fail much more quickly than higher quality ones will and will often cost more in the long run because you'll go through many more cheap disks than you will high quality ones.

Now, when you're starting out, it's perfectly, 100% acceptable to start with cheap tools because going deep into debt to buy high quality tools (especially if it's a hobby and you're not sure you'll continue) just doesn't make sense.

Technique can help prevent issues.

• You really shouldn't press down hard on the sander at all.
  • The weight of the sander plus your hand resting on it to control & move it is sufficient. Pushing harder can bog down the motor, sometimes to the point of stopping the rotation or orbit, leading to excessive sanding in one spot, which just means that you've got to work even harder longer to get a smooth finish.
  • Pressure also builds heat which causes the disks to die even faster.
  • Excessive pressure can also reduce or prevent the extraction of dust from under the disk, reducing effectiveness and building more heat (see point above).
• Move the sander at the proper rate across the board.
  • Graphus mentioned a "10 count per foot"
  • I've seen recommendations of 1 second per inch of wood
• The "pencil trick" is a very good indication that you're doing a quality sanding job
  • Using the broad side of a pencil (or a fat pencil like a carpenter's pencil) scribble across the surface of the board.
  • Sand until the pencil marks are gone
  • Check your work. If it's satisfactory go on to the next higher grit
  • If you see a spot that still has pencil marks, but all around it the marks are gone, you've got a low spot on the board. Scribble on the whole thing and sand the whole surface again. Lather, rinse, repeat until you've got the whole thing flattened to that low spot.
  • If you simply sand the pencil marks out of that spot using the edge of the disk, you're just making the dip worse, not better.

If that is the sanding pad going bad, you can purchase replacements. This would be a good opportunity to splurge an extra couple of $€£ for a quality replacement pad. Get one that's the same diameter as your sander (5" or 6", most likely) and replace it. That's a simple and good place to start.

If it's the sanding disk itself, it's likely that it was just junk to begin with or that you've overheated it, causing all the issues noted above, plus getting it so hot that you're melting the Velcro on the back of the pad. Go lightly with your next disks to reduce these issues.

It's OK to use up the cheap disks you've got, using proper techniques and replacing the disks much more often than you'd expect, then replace the disks with higher quality ones. While a home-improvement center will sell you dirt cheap ones, they'll also sell higher quality ones. A wood worker's specialty store will sell even better quality ones. Most will help answer questions and guide you to a mid-range that are reasonably priced yet still better quality than WalMart.

You'll be shocked at how much better a quality disk is and how much easier sanding is.