2 tumbler questions

Hello all: I just bought some machined aluminum drops, which look
like they were lathe- turned. For my use, they still have excessive
machining marks. I would like to know if tumbling would remove the
circular machining marks. There’s also a bur where the hole for
hanging was punched or drilled. I have never tumbled aluminum
before, just silver, brass, and copper. I do have Judy Hoch’s
tumbling book, but it doesn’t mention aluminum. I’m not planning on
anodizing them, just using them plain.

So can I tumble aluminum?

I have the following supplies:

Gy-roc B vibratory tumbler
Rotary tumbler (new, still in the box)
Aqua Clean-cut media from Rio
Quartz pyramids from IJS
Porcelain Burnishing media (grey cylinders,new, not broken in yet)
Stainless steel shot
Walnut shell 
Walnut shell with chrome oxide
2-DL polishing cream from IJS, for walnut shell
Red Buff, Rio
Green Buff, Rio
Brass deburring liquid, Rio
Gold and silver deburring liquid, Rio
Stratosheen, Rio

Second question: The deburring liquids come as a concentrate. I
mixed up a gallon in a plastic milk bottle, 2 ounces to 1 gallon
water, used some, put the bottle on a basement shelf and didn’t
tumble for a while. When I came back to it today, the milk bottle
had leaked on the bottom and created quite a mess.

So: is it a bad idea to mix up more than for immediate needs? What
can this stuff be stored in? The original bottles for the
concentrate look fine. The bottles don’t detail what this stuff
really is; I figured it was some harmless form of soap. But it broke
down a plastic milk bottle??? The spill leaked on a lot of items,
mostly tumbler equipment and cartons of media, metal shelving,
concrete floor…how scrupulous do I need to be in cleaning
everything off? (I’m SO glad I moved the wine rack last fall!)

Thanks in advance!
Lin Lahlum

Most compounds will be aluminum friendly. Many are alkaline and
may attack the metal somewhat but even most of these are
considered ok for aluminum. The aggressiveness required of the
media will be based on the initial material roughness and your final
finish requirement. These sites may supplement Judy’s book:

http://www.belairfinishing.com/practical_guide_to_mass_finishing.htm

http://www.finishers-management.com/april2002/massfinishi.htm

Milk bottles polyethylene is pretty chemically durable but some
organics will bleed through them and they are not a good item
mechanically as a durable storage container. Container sold for
fuel and other organic ( anti freeze) liquids should have been
fluorine treated and will work for you.

Jesse

I had the same experience you did in that the deburring solution
leaked out of the distilled water plastic bottle. There might be
something in the solution that weakens the plastic bottle. However,
several years ago the companies used to print “date expired” on the
cap. When I asked how distilled water could go bad, the store
manager said the plastic bottle, not the water, expires after a
time. A similar leak did not develop in the burnishing fluid, but I
don’t premix it anymore because the soap forms lumps rather than
smoothly going into solution. Instead, I add a small amount of
burnishing powder directly into the tumbler. Nancy www.psi-design.com