Class Offer - Intro to Rotary Rock Tumbling

[jkraai]

I'll be giving a class to another group in getting started rock tumbling.  While it's fresh in my head and I have the stuff out to do it, I'd like to offer it to Area515.  What's the procedure to schedule a class?  Would a $2-3 fee per family cover the utilities?  I won't be charging anything for giving the class.

Summer weekends are busy times, so I'm leaning towards doing this on a weekday evening starting at 6:30 or 7.  If you're interested, reply (to all or just to me) with a weeknight to let me make a list of people and to set expectations of the where/when of it all.

"It's fun for kids and adults alike" to see the transformation of rough rock into something shiny and smooth.  Shiny, smooth stones can be easily made into a pendant, etc.

I have a few different tumblers, rotary and vibratory, to bring and show.

Tumblers appear on the normal used channels or cheap ones can be found at Harbor Freight and Hobby Lobby.

Outline (work in progress, will flex depending on audience):

Introduction to Rotary Tumbling

1. How tumbling works

2. What about the noise?

3. What to tumble

1. Hardness:  like-with-like & harder is better

2. Uniform composition

3. Size & shape--no cavities or protrusions

4. What’s “tumbling media” & “indicators” ?

4. Grits and polishes

1. Different sizes of grits remove different sizes of features and scratches

5. Steps ( also see checklist handout )

1. Pre-tumble

1. Gather supplies

1. Rock tumbler

2. Grits & polish

3. 4 old toothbrushes, labeled "Coarse," "Medium," and "Pre Polish," and “Polish”

4. 4 plastic colander(s) or plastic tubs, 1 for each step

5. 5 indicator pieces

6. A dump / evaporation bucket

7. Checklist for each batch

2. Check tumbler

1. Check rubber drive belt

2. Oil bearings/bushings according to the manual

3. Run dry & listen for odd sounds

2. Coarse Grind & Finish - normally 2 weeks

3. Medium Grind & Finish - normally 1 week

4. Pre-Polish & Finish - normally 1 week

5. Final Polish & Finish - normally 1 week

6. How does Cerium Oxide Polishing Work?

7. Burnish - Like Final Polish

6. Tips

1. NEVER dump grit down a drain

2. Avoid cross-contamination of grit like the plague.  Clean and rinse it again.

3. A pound of rough at the start does not mean a pound polished at the end

4. Use a Tumbling Notebook to take notes as you go

5. Don’t let rocks dry out at any time during the process

6. If you need to take a break, double-bag tub with rocks in sealed plastic bags to prevent drying

7. Never use metal--colanders or scoops

7. Variations

1. The Two-Step Tumble

2. Vibratory tumblers

3. Dry vs. wet tumbling

4. Tumbling Things that Aren’t Silica

1. Know the material, know the hardness - Review Moh's Hardness

2. Softer material:  cut long-run times in half, consider softer grit

1. feldspars, glass, apache tears, obsidian

3. Harder material:  Double (or more) long-run times

1. garnet, topaz, corundum

4. too soft?  calcite, fluorite, anything below Moh’s 5

5. too hard?  anything harder than your grit. SiC is Moh’s 9-9.5

6. Problematic:  Jade--”undercutting” due to non-uniform composition

7. Just don’t:  Opal, delicate or porous rocks, fractured minerals

[Bailey Mader]

Do you want to open it to just members, or post it publicly? 

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[jim kraai]

I'd gladly do either or both.

What's your gut feel?

Maybe if a 'members & close friends' session goes well, we do it again for the public with adjustments from lessons learned.

[beernutz]

I would definitely be interested.  I could maybe find a sub for my normal Monday or Wednesday night leagues if either of those work.

[David Champion]

IMHO, open it up to everyone, if you're really worried you'll have too many people use an eventbrite or email rsvp to limit the class size.

-dc

[Bailey Mader]

We can do that. You going to be around the space tonight for open house, Jim? We can get it up then, or email me later and I'll help you get it posted where it needs to be. 

[Tim-S]

On Tuesday, June 16, 2015 at 12:55:55 PM UTC-5, David Champion wrote:

IMHO, open it up to everyone, if you're really worried you'll have too many people use an eventbrite or email rsvp to limit the class size.

-dc

Completely agreed. Sounds like a cool class!

[jim kraai]

How about Wed, July 8, 7-8PM?

For now, let's stick with ( membership intersect people on this list ) and their immediate families.  (Do we have a general liability waiver for general public?)

Children with their parent(s)/guardian(s) are welcome.

I don't know about tonight.  I will be downtown for supper, which is unusual.

[Bailey Mader]

I'll put it on the calendar for starters. Let me know what details you want added.

[Ray Scheufler]

I do not believe that we have ever developed a different waiver for visitors vs members.  The waivers that we have are on the second bookshelf in from the door.  They are in a black folder.

Ray Scheufler

[Bailey Mader]

No, they are the same, and we should probably make sure everyone who IS a member has signed one.... Anyone know where we keep the SIGNED ones? Those in the black folder are fresh. 

[Ray Scheufler]

There are some signed ones in the folder as well.  When I have had people sign them, I put the signed copies in the back of the same folder.  I will look around this evening for a better location to keep the signed copies, we have enough file cabinets.

Ray Scheufler

[jim kraai]

Update!

May I please teach the class on Wednesday, July 8 from 6-8PM?

[Bailey Mader]

Sure thing. Updated on the calendar.