[CAS14]

In 1974, I took a position with Kaiser Steel, to help identify metallurgical coal resources on their 530,000 acres of minerals near Raton, NM. I had read an old USGS report about igneous sills that had invaded the York Canyon coal seam in their "Upper York Canyon" area. A core hole proved this old report to be correct. I recovered some great igneous core from the stratigraphic horizon that should have been coal.

I've kept this for all these years, it's just sentimental. So I plan to make an interchangeable topper from this, unless I screw it up.

I plan to square off both ends so that I can drill perfectly vertically to install a threaded insert or coupling. Then I plan to grind and sand off the top end so that it is rounded. Carborundum (wet/dry) sandpaper will do the job from past experience.

 

[Rodney]

Keep us posted as you work with it. My experience working with stone is limited and I'd like to learn more.

Are you polishing it too or leaving the finish as-is?

Rodney

 

[Gloops]

A great project when polished up it will look superb, what is it's strength like for resistance to being dropped accidentaly ?

 

[CAS14]

This, as with most rocks and minerals, will shatter fairly easily if it strikes a hard surface. As the igneous rock cooled, shrinkage cracks formed which are weak. Voids were filled with calcite, as hot fluids moved through them much later. I could crack the rock simply by drilling into it.

My Cherokee geologist friend had a ceremonial staff topped with a large quartz crystal. He dropped that and the crystal shattered. This problem is the reason that I plan to make the topper replaceable, in fact interchangeable with those I've made for one of my first sticks.

 

[CV3]

Challenging and great project CAS14. I look forward to following you progress.

 

[cobalt]

different . like it interesting project

 

[CAS14]

Today was the last warm day for a few days. I sawed off about 2 1/2 inches and began sanding. The vibration during sawing caused the remainder of the core to fracture into two pieces, not a good sign.

The core is 2 1/8 inches diameter. The top of the stick is only about 1 7/8 inches díameter. After drilling, if the core doesn't fracture, I'll have to round or taper the 90 degree edge to match the diameters.

After quite a lot of 80-grit sanding the diamond drill bit striations are still faintly visible.

The grandkids were over for the Friday after-school chaos. Our grandson brought his most recent stick for a minor repair. It's not easy to remain focused on one project, but it's all good.

 

[alador]

Looks like a cool project. I have some mineral spheres that I have thought about using for walking stick knobs. There are several techniques online for stabilizing stone for grinding etc. but I suppose with your background you probably familiar with them already.

 

[dww2]

A few months ago, I bought a set of diamond hole saws to try what you're doing and maybe make stone collars for multi-piece sticks. Looking forward to seeing your results!

 

[CAS14]

Both the top and the bottom must be square. The top will rest on the drill press table when the hole is drilled into the base. Of course the base will rest on the squared top of the stick. Hopefully this nearly universal challenge of drilling the stick for the hanger bolt will be successful.

 

[Rodney]

Good luck with the drilling. Do you use any coolant when you drill?

Will a file touch the stone? You may be able to speed up the shaping and smoothing a bit if one will work.

When I was working with that piece of jade I found I could shape it with a file. The stone pretty well ruined a new sanding disk when I tried that.

Should be a pretty topper when you're done.

Rodney

 

[CAS14]

Good luck with the drilling. Do you use any coolant when you drill?
Will a file touch the stone? You may be able to speed up the shaping and smoothing a bit if one will work.
When I was working with that piece of jade I found I could shape it with a file. The stone pretty well ruined a new sanding disk when I tried that.
Should be a pretty topper when you're done.
Rodney

I'm afraid to use a masonry bit due to the vibration, and I'm not set up for coolant on the drill press. In addition, I'm afraid to apply too much pressure due to the risk of splitting the core. Very slow going! Beginning with a very small bit.

 

[CAS14]

The small metal bit wasn't cutting it, and is ruined after penetrating less than 1/8". I've bought a cheap 3/8" tile bit, and I'll squirt water on it periodically. Maybe this will work, maybe not.

 

[MJC4]

Interesting project CAS, The rock hound across the street uses diamond bits to drill his polished rock projects.

 

[CAS14]

The cheap tile bit wore out about 1/8" too soon. My goal was to leave just a couple of threads as an anchor for the overlying JB Weld or epoxy.

I have two options, cut off 1/8" and the threads, or buy another tile bit and risk fracturing the core. I'll sleep on it, but I'll probably take the risk and buy another bit.

 

[dww2]

Maybe try drilling it while it sits in a dish of water. I've seen a few you tube vids on doing it this way and they seem to have good luck.

 

[Rodney]

Score the smooth part of the bolt with a file or hacksaw or grinder so the epoxy has something to grab. No risk to the stone that way.

Rodney

 

[Gloops]

Good luck with it, keep us posted.

 

[CAS14]

Score the smooth part of the bolt with a file or hacksaw or grinder so the epoxy has something to grab. No risk to the stone that way.
Rodney

Rodney, great suggestion! I did that and scored the shank with a file. I just used JB Weld to secure the cut-off hanger bolt, and now I'm thinking about how best to perfectly align this with the threaded insert in the stick.

 

[CAS14]

The next challenge is to perfectly align the shank with future threads in the wood shank.