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[Rockhound1974]

Hello all
I'm rekindling my love of geology after a trip to the UP in Michigan. As a kid I would pick up rocks and fossils and then catalog them. I've kept quite a few over the year. I recently took a trip to Michigan's UP and picked up some agates as well as other rocks along Lake Superior. I purchased a rock tumbler and have my first dual 3 lb project running. I had one of the plastic drum units when I was a kid and didn't have the patience to let it go through completion, but now i'm exercising patience on this project. I found a local rock shop that sells bulk grit which saves quite a bit over the Thumblers grit packs, so i'm excited to see how my project turns out.

I also picked up two larger agates along Lake Superior and i'm interested about polishing them. Can I polish them using a dremel tool. I've hear of "windowing", i.e. just polishing a section off the agate and thought that a dremel might do the job. Any suggestions on steps and which attachment to a dremel I should use during each step would be helpful. Attached is a photo of my two larger agates (both found near Muskallonge Lake State park in Michigan's UP). One was between Grand Marais and Muskallonge Lake and the other was at the State Park.

[lithicbeads]

Hi and welcome, Always glad to see new folks on our new site. There are people here with dremel experience so I will defer to them on that subject. Do you ever see any Mary Ellen jasper from your area? We have similar jaspers out here in Washington state.Things are a bit slow on all the forums for the summer break but people will be back responding soon.

[Rockhound1974]

Hi and welcome, Always glad to see new folks on our new site. There are people here with dremel experience so I will defer to them on that subject. Do you ever see any Mary Ellen jasper from your area? We have similar jaspers out here in Washington state.Things are a bit slow on all the forums for the summer break but people will be back responding soon.

I actually don't live in the UP. We were vacationing there-will surely go back though. I live in Indiana...the limestone capital of the world : ).

[Enchantra]

Welcome!   
I'm in sunny and warm Arizona!

You could probably easily polish those two stones by putting them into your tumbler with some smaller stones and the grit you mentioned. 
If you only wish to polish just one section you can use your Dremel.  For the initial process 3M has these abrasive impregnated sanding wheels that will take off the initial layers of material.  Then you will want to find finer and finer grades of polishing wheels for the Dremel.  Barring that several grades of a good wet/dry sandpaper will work just as good, they will just take time.

[hummingbirdstones]

Welcome to the forum, from Northern Arizona!  Before I moved to Arizona about 6 years ago, we were kind of neighbors.  I lived in the Chicago suburbs for most of my life.

There are a number of ways you can window those stones -- Amanda mentioned a couple.  3M makes some abrasives that will definitely do the job.  Hi-Tech Diamond also has diamond impregnated mini disc sets that work with dremels.  Here's a link:  http://www.hitechdiamond.com/Mini_Smoothing_Disc_Kit.html

I would probably buy a few diamond burs in a cylinder shape in maybe 180 grit or so to start the window and then move through the finer grits to polish up your window.

[lithicbeads]

I love the bigger hi tec sanding pads, very effective.

[Gergis]

Welcome fellow Midwesterner!(I'm originally from Wisconsin now Washington) :-)

Sent from my LGLS990 using Tapatalk

[Rockhound1974]

I love the bigger hi tec sanding pads, very effective.

Do you have a link to a supplier of these? Or are you simply talking about the foam sanding blocks you can get at Lowes?

[Rockhound1974]

Welcome to the forum, from Northern Arizona!  Before I moved to Arizona about 6 years ago, we were kind of neighbors.  I lived in the Chicago suburbs for most of my life.

There are a number of ways you can window those stones -- Amanda mentioned a couple.  3M makes some abrasives that will definitely do the job.  Hi-Tech Diamond also has diamond impregnated mini disc sets that work with dremels.  Here's a link:  http://www.hitechdiamond.com/Mini_Smoothing_Disc_Kit.html

I would probably buy a few diamond burs in a cylinder shape in maybe 180 grit or so to start the window and then move through the finer grits to polish up your window.

For the final polish do you simply make a heavy slurry with Ti or Al polish and dip the disk into it and polish?

[hummingbirdstones]

The final polish pads that come with the set are pre-charged with cerium oxide, so all you need is a bit of water to work with them.  I have never used their final polish pads as those are a newer product that wasn't available when I first started using the Hi-Tech discs and purchased the sets for my Dremel.  They have a few different size sets from 1/2" up to 1-1/2" to work with.  I cut my first boulder opal using a Dremel, these little guys and a tub of water on my patio back in Chicago.   

[Rockhound1974]

The final polish pads that come with the set are pre-charged with cerium oxide, so all you need is a bit of water to work with them.  I have never used their final polish pads as those are a newer product that wasn't available when I first started using the Hi-Tech discs and purchased the sets for my Dremel.  They have a few different size sets from 1/2" up to 1-1/2" to work with.  I cut my first boulder opal using a Dremel, these little guys and a tub of water on my patio back in Chicago.   

Thanks-
Do you think the Dremel tool linked below would work well. I held this one at Lowes and thought with the size would give good control in working on the rocks. I think I need to get a vise as well given that it's probably not very safe holding the rock in one hand and polishing with the other (especially given that i'm a newbie).
http://www.lowes.com/pd_571072-353-3000-1-25___?Ntt=dremel+3000&UserSearch=dremel+3000&productId=50168159

[Rockhound1974]

Welcome!   
I'm in sunny and warm Arizona!

You could probably easily polish those two stones by putting them into your tumbler with some smaller stones and the grit you mentioned. 
If you only wish to polish just one section you can use your Dremel.  For the initial process 3M has these abrasive impregnated sanding wheels that will take off the initial layers of material.  Then you will want to find finer and finer grades of polishing wheels for the Dremel.  Barring that several grades of a good wet/dry sandpaper will work just as good, they will just take time.

These are much too large for my tumbler (dual 3 lb barrel). Did you see the penny for the size comparison?

[hummingbirdstones]

Sure.  Variable speed is good.  Only caveat is to be careful using it around water which you need to use the discs.  I bought the flex shaft attachment back when so it was easier to maneuver with just one hand holding the  flex shaft and the other the stone right above my tub of water.  That way I could dip either the tip of the flex shaft in the water or dunk the stone to cool it off without any trouble.  If you can rig up some type of drip system, that would work too.

[ToTheSummit]

Welcome to the forums.  Its a great place with lots of knowledgeable and helpful folk (as you are already finding out).  I dig the agates but I have nothing more to contribute that hasn't already been offered so I will just look forward to seeing what you do with them.

[Enchantra]

You could probably easily polish those two stones by putting them into your tumbler with some smaller stones and the grit you mentioned. 

These are much too large for my tumbler (dual 3 lb barrel). Did you see the penny for the size comparison?

Yes I saw the penny.  I have seen stones as big as these and larger tumbled.  It depends on the tumbler of course.  Might be a touch much for a 3lb but a 5 lb could probably take it.