Gang, THIS IS IMPORTANT! Must-read stuff alert! It JUST happened AGAIN last week, I was sent a pickup to fix, and when I took a look at it the problem was clear, STEEL WOOL! You see, when you use steel wool to polish the frets on your guitar, you end up with thousands of tiny steel bits EVERYWHERE; and those bits will be strongly attracted to your guitar's magnetic pickups. What's next? Best case scenario is you wind up wasting a lot of time with sticky tape, tooth picks, and tweezers ridding the pickup of all the little steel intruders. Worst case: dead pickup! And, even if you don't totally kill your pickup, the addition of thousands of tiny bits of steel into a magnetic pickup will seriously effect the tone of the pickup. Let's dive in a little deeper!
So, the old standard of days gone by was, in fact to use extra-fine steel wool to polish up your frets; messy, but that was fine before the days of those new-fangled ELECTRIC guitars. So, when working on electric guitars, it became standard practice to tightly tape-off the pickups, electronics, and any body cavities before going after it with the steel wool, and effect a thorough clean-up of steel shards afterwards. Now if you just flat NEED to use steel wool, then I guess this is the best course of action, but here's why I don't like that method. If, like me, you do MANY guitars on your bench, and also have MANY magnetic pickups, speakers, and tools in your shop, you are still inviting big-time trouble. Why? Because over time you are creating literally millions of steel bits that float EVERYWHERE in your shop; no matter how hard you try, you will never clean all those tiny steel slivers up. Over time, you're shop will become downright infested by steel slivers, and they WILL find their way to pickups and speakers, and they can wound or kill a speaker as easily as a pickup! A voice-coil gap full of steel slivers leads to a gnarly sounding speaker that will eventually fail.
So, if steel wool ain't the proper tool for this job, what is? Thankfully Stewart-McDonald has thought this question through many years ago and provided us with downright elegant solutions. Here are my favorite fret polishing products, all of which will leave no little ferric stragglers! This is going to seem like an overt advertisement by Stew-Mack, but I assure you, I have no connection with them apart from using a ton of their products.
Flexible Polishing Papers: These single-handedly replace steel wool with no steel, so if you want, you COULD stop right here!
Fret Erasers: These are my least favorite item on this list for polishing frets, but there are still certain situations where I choose them first.
Fret Polishing Wheels: If by chance you cling to steel wool because it's "fast", you certainly haven't used these! With the right flexible shaft Dremel tool, these will flat out-shine anything else, and in record time!
Fingerboard Guards: Taping up an entire fret-board is quite time-consuming, so with all the products above, I always use these. I do not use the rubber-bands, I simply move them from fret to fret, it's fast and beautiful.
There ya go! Now you have no excuse for continuing the barbaric practice of polishing your frets with a product developed in 1896 for cleaning household cookware! Be a true Pro. Check out the above links, Stew-Mac has instructional videos on many of these products, which I also suggest watching.