Titanium Grinding vs. Tumbling

May 1, 2008

Harbor Freight bench shear

I’ve tried a few different methods over the the years to reduce my hands-on time in getting rid of those razor-sharp fresh-cut titanium edges. I started doing this with essentially no tools or money to buy any. I first bought tin snips, and then a small bench shear something like the one pictured.

Polishing MotorThe merciless edges on fresh cut titanium encouraged me to buy leather gloves. To remove those edges, I first used emery paper (wet/dry sand paper) to smooth them. But the tedium soon urged me to learn that a motor, a couple of taper spindles, and Cratex wheels (rubberized carbide) were much faster and spit few sparks. I put my grinder/polisher together from a salvaged ΒΌ horse motor and parts from a mail-order catalog (this was around 1980). Now there is website: www.RioGrande.com and you can get everything there. But grinding small parts ended up using up finger tips; both gloves and my own.

Harbor Freight Cheap Rock TumblerOn a whim, I tried out my childhood rock tumbler. I just cut up a bunch of pieces, and threw them in with some rocks, and let them go for a week, then three weeks. There was some rounding of the sharp edges, but not much nor fast. I then ordered abrasive ceramic media from RioGrande, and tried that in place of the rocks. After a couple of weeks, nice, smooth edges. The ceramic media lasts for many uses (I have yet to reorder). You can also get it cheaply from HarborFreight, here or at your local Harbor Freight shop. You can also try rock shops, craft stores, or online.

Lightweight vibratory cleaner/polisherBut, c’mon! Weeks? So (many years later) I went to eBay to find a vibratory polisher. I wasn’t ready to spend $500 on a name-brand one at RioGrande. So I found one specified to clean shotgun shell casings for about $60 delivered. It has a clear top, so I could watch the pieces and media do their thing. It reduced the time to about 4 days. I ran it with a dry load, with no water or agents. Amusingly, the dust that grinds off from the media is hydophobic! Water runs right off of it, like mercury on glass. I found that adding tap water at the end and vibrating for another hour suspended the dust in the water and didn’t darken the titanium too much. Anyway, I etch after I tumble.

But I never did manage to get a shine with this machine. I tried ceramic media and porcelain media, I used polishing compounds, ran it wet, ran it dry, and still my best was a matte finish. My worst was that the titanium turns almost black in water with porcelain.

Harbor Freight Vibratory PolisherSo I thought I’d try another type of vibrator. I got it from eBay, and then found that I could have driven across town to HarborFreight and gotten the exact same unit for about $25 less. I first tried running it wet with porcelain. Blackish titanium, eww. I etched the titanium clean, and then tried dry with ceramic media: Shine! Trumpets and doves and a beam of light from above. The gray ceramic media turned dark and shiny in 24 hours, as the titanium deburred and gleamed.

Had this not worked, I would have finally bought a professional (expensive) circulating fluid vibrator assembly (Raytech). But I’ll hold off on those.