Harbor Freight Tools 90979 - Manual (Page 6)

SKU 90979 For technical questions, please call 1-800-444-3353. Page 6
Oxide, or Titanium Dioxide. When tumbling hard materials, it might be necessary to
repeat the steps.
Note: More specific instructions for each step are covered under “Specific Instructions”,
below.
Approximate Amounts of Abrasive (for each Barrel)
Coarse Grind Medium Pre-polish Polish Burnish (soap)
4 Tbsp. 4 Tbsp. 6 Tbsp. 6 Tbsp. 1 Tbsp.
Note: An Abrasive Kit (not included) is available through Harbor Freight Tools, Item #
30956. This kit includes 4 oz. of coarse grit abrasive, 4 oz. of fine grit abrasive, 2 oz. of
pre-polish abrasive, and 2 oz. of polish abrasive.
5. Add enough water to reach the bottom of the top layer of rocks.
6. Seal the Rubber Barrel (22), and replace the Barrel Lid (28), Knurled Nut (24) and
the Washer (26).
7. Set the Rubber Barrels (22) on the rollers, set the stops, and turn on the Power
Switch (13). Make sure you check during the first ten minutes to make sure both of the
tumblers aren’t leaking.
Note: Although this manual primarily deals with rock/gemstone tumbling, you can use this
Tumbler to work with metal and metal jewelry (without gemstones). This Tumbler may
be used to take the jagged, sharp edges off of small metal parts. To polish brass, gold,
silver, or copper, Harbor Freight Tools offers Polishing Media, Item # 46377.
Note: For more in-depth information on polishing jewelry, we recommend you purchase a
jewelry polishing handbook.
IV. Specific Instructions
IV-a. First Grind:
Run the Tumbler for 24 hrs., turn the tumbler off, remove the Barrel (22) , and slowly
open the Barrel Lid (28), releasing the small amount of gas that builds up during the process.
Check the stones, which might show a little rounding, but not much. Clean the seals and
close. It is important to release the gas as it will turn the abrasive slurry, into a thick substance.
After another 24 hrs. check again. If the slurry is thickening, add a little water. Run for one
hour and check again. If it is still thick, add some more water. Let the Tumbler run continuously,
but check daily. Continue this process for 7-10 days to remove the sharp edges and rough
areas. Be patient. This is the most important step. When all of the edges are rounded you are
ready for the next step.
Note: Between steps you must clean the Rubber Barrel (22) and stones. Pour off the slurry
into a disposable container (i.e. a milk carton) and take care that the stones remain in
the Rubber Barrel (22).
Warning!! Never pour the slurry into your home plumbing system.
Next, remove the stones into a clean container or plastic bag. Finally, fill the Rubber
Barrel (22) 1/2 full with water and clean out the remaining slurry and grit. Wipe it clean with
a wet paper towel and then wipe it dry. To clean the stones, gently slosh them around in clean
water and remove them a few at a time checking for breaks or cracks. Discard broken or