Is anyone using a wood working drum sander, modified or not, to remove dross on their work? Currently I am using flap discs but would like a way to speed the process up.
From what I have found on google a lot of people don’t seem to think they will work as you will tear up the drum. Although one youtube video said it works fine with hook and loop sandpaper installed to give it a little cushion.
Would love to hear from someone who has made one work or tried one that didn’t end up working.
Is pretty interesting
I wouldn’t do it. If a chunk hangs up it will tear the crap out of your sandpaper and possibly your drum (which is made out of aluminum).
The method that works well for me is to use a 55 degree angle variable speed drill with a 2 or 3 inch H&L sanding pad holder and some silicon carbide sandpaper, 120 grit works well: https://www.amazon.com/gp/product/B0824XPX6F
The flap discs work fine as well, but at times I have 10-20 pieces to clean up and it gets old. What you said about tearing up the drum and paper is certainly a concern, but without testing it out im not exactly sure how much of one.
Hoping to find a cheap used unit to try, if no one has any first hand experience.
Not exactly what you are asking, but I find that dross tends to smear and not come off all that cleanly with sanding. Also that it is very easy for a the abrasive to cut more of the relatively softer metal while leaving the dross. What has worked great for me is this heavy duty scraper or for more intricate parts, a cold chisel. I knock the top dross off before moving the part, then flip and knock the backside dross into the water table—takes seconds. 
I use an axe. I don’t worry about it getting dull, because I don’t use it for anything else. I would not use it on intricate items, but it works for me on 1/8 and thicker material.
I find a welding chipping hammer works well.
So much easier to knock off what you can before hitting it with a abrasive disk on a 4"grinder to clean it up.
My current set up that works good is to use a needle scaler to rattle the crap out of the back side, and then finish with a flap disc.
All of these methods listed seem fine, and im sure they work. My issue is when I have like 10-15 14x24" pieces for a customer it takes awhile, which is time I could be cutting more stuff if I was able to speed the process up.
They actually make drum sanders that are made for steel, called Timesavers, but they aren’t cheap and extremely hard to find used. I’m looking to take a gamble on an old drum sander and see if I can modify it to work somehow, I just need to find a good deal on a used unit.
Twisted cup brush has been working great for me. The hammer leaves marks. From 16ga to 5/16 all of my dross is about the same size and the cup takes it right off.
I just drop it on the floor a couple times, flat on the floor. %90 falls off, the rest a flap disc knocks it right off.
On my garage’s concrete floor 
Didn’t work in the bike barn when I missed some before bead blasting and powder coating.
The better your power/speed settings are dialed in the less dross you get and the easier it is to knock off too.