Mill Scale Removal

chavez556

chavez556

Joined
Jan 10, 2011
Messages
1,448
What is the best way to remove mill scale without a surface grinder? I'm currently using a magnet+ flat platen to remove most of it then hitting it with a file then sanding with 80 grit sandpaper. There has to be an easier way. I'm using a CM 2x42 w/ ceramic platen.
 
You can help descale with acid.


vinegar is diliute and goes slower - safer

Muratic can be diluted too.



How long ? depends on acid strangth, temperature and such

test it for yourself, too long is bad too.
 
All of my blades are forge finished, and I remove the scale to leave the texture beneath by soaking in 9% vinegar overnight, washing off the sludge, and sanding any spots that might still have lingering scale.
 
I keep a tube (3 or 4" PVC schedule 40 with a sealed cap on one end and a clean-out plug on the other) of "pickling solution" on hand for scale removal when necessary or desirable. Just buy Sodium Bi-sulfate from the Pool Supply section of the hardware store, and mix with distilled water.. Doesn't take a ton, a cup or two maybe.. It's faster than vinegar IMHO and more effective.


That being said, I almost *never* bother with mill-scale removal anymore.


As far as forge scale goes, when making damascus for example, I'm with Don. Nothing beats a quality angle grinder.. Although I've been in the shops of other's who have dinky little angle grinders with big-box store grinding wheels, and wanted to kill myself. Contractor grade (very different than the standard) DeWalt is the minimum (much higher amperage than the smaller ones), but a large 7" or so Metabo is ideal. I either use the big cone stones or Radnor wheels from the welding store. They break down rather than glaze, and keep cutting.
 
I'm no Damascus guy, but something I saw recently on another forum that might help folks cleaning up layers when building a billet is using masonry wheels on an angle grinder to grind scale off. This from a well-known swordsmith with several books out on the subject. :)
 
If you see a diamond grinding disk for your 5" angle grinder for sale, buy it!
I know, I know, it costs as much as the grinder, maybe more, but it lasts forever and eats scale like you wouldn't believe, plus you don't have to breathe abrasive dust.
(should be wearing a mask, but sometimes we don't)
If you do any amount of grinding work at all, you'll see why I say this- I tried one at a show and went out and spent the bill and never regretted it. Nothing else comes close- I put away my big stone/9" grinder combo.
The only downside is that it's a bit aggressive for some uses at 36 grit.
 
You must log in or register to reply here.
Back
Top