I have just bought a polishing pad & sheepskin wool pad from Festool and have used them to clean up my table saw top. Now they are both covered in black stuff.

Is there a best way to remove it and also, is it ok to use the same pads on wooden surfaces? Or do I now need to get a new set just for wood and leave the other ones to metal?

Note: I used a Festool cutting compound on the polishing pad.

  • What did you use with the polishing pads, any kind of polishing compound or wax? Or it is just black metal residue? Either way please state it in the Q. It's possible that you can just ignore this for now, like you can ignore the black buildup on buffing wheels for a certain period. You can't use one common technique for getting that off buffing wheels unfortunately as it's to buzz a saw edge against the spinning wheel. It's possible that a little mineral spirits might allow you to remove some of the residue, and/or laundering or thorough hand washing, although they'll never be spotless again. – Graphus Mar 12 '19 at 6:16
  • Willing to be proved wrong but I think you won't be able to use these on wood or polished wood surfaces with safety, sorry! Given it's Festool I imagine they cost an arm and a leg :-( – Graphus Mar 12 '19 at 6:18
  • Thanks @Graphus, have added a note at the bottom of the question re: compound – Grant Mar 12 '19 at 9:12

The black stuff is iron particles that have been abraded from the table saw top. To remove them from your pads, you'll have to dissolve them.

The good news is, it appears that the festool cutting compounds are water-alkane emulsions, which means that you should be able to remove the majority of the residue by simple laundering with clothes detergent. I would do so by hand, and gently, given then at least one of them is made of wool.

Following that, there will probably still be some black residue remaining. Acids are the easiest way to dissolve these. Again, given the wool composition, I would go with weakest acids first - soaking in ample vinegar (acetic) or cola (phosphoric) will probably work. If those don't work, I would use dilute hydrochloric acid (commonly found as toilet bowl cleaner) - work your way up from extremely dilute to more concentrated. Following the acid treatment, launder again in multiple washes of plain water. Remember to be physically gentle so as not to ruin the wool structure, and to only be as chemically harsh as you need to be, and be patient - the vinegar/cola might take a day or two of soaking.

  • 1
    Where I am from, toilet bowl cleaner is more often bleach (which is alkali) than hydrochloric acid. – Martin Bonner supports Monica Mar 14 '19 at 13:08
  • strange. Well, look at the ingredients/warnings - it will be obvious which are bleach based or acid based. – aaron Mar 14 '19 at 14:17
  • Hydrochloric acid (HCl) is often sold as "muratic acid" in the United States, and can be found in hardware stores and big box stores like Home Depot and Lowes. It will DEFINITELY need to be diluted if you buy it that way, though concentration can vary. Be careful with it, it's one of the more powerful acids you can buy retail without going to a specialty supplier. Don't dump it down the drain. Dispose of it at the same kinds of places you'd take other toxic chemicals. Consider having a bucket of water on hand whenever you work with it, to quickly dilute it if any spills on you. – Katie Kilian Mar 14 '19 at 14:20
  • @CharlieKilian "Don't dump it down the drain" - why not if well diluted? It is completely innocuous in the environment at low concentrations (unlike, say, mercury or dioxin). (Your stomach is full of moderately concentrated HCl.) Bucket of water is a good idea though. Final thought: you can buy it in the UK as "brick acid" (for cleaning concrete stains off brickwork). – Martin Bonner supports Monica Mar 14 '19 at 14:30
  • 1
    Yes, if it's diluted well enough it should be fine. But mostly I was advising not to dump it down the drain because people don't always know what kinds of pipes they have in their drains. PVC and other plastics are usually unaffected by acid, but (ETA: some) metal is decidedly not. As you said, if it's diluted enough it is fine. But I was erring on the side of caution in my advice. If one does dump it down the drain, I'd advise running plenty of water afterwards, just to be safe, and to make sure it didn't get stuck in a trap somewhere. – Katie Kilian Mar 14 '19 at 14:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.