Making a mineral thin section slide by hand.

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The QCC
Posts: 397
Joined: Sat Oct 11, 2014 10:13 pm

Making a mineral thin section slide by hand.

#1 Post by The QCC » Mon Mar 23, 2015 3:56 pm

An almost step by step slideshow of how I made a thin section slide of Hobby Sand.
This is the follow up of my previous post Hand made thin section of hobby sand
The slide presentation shows the main steps, tools and methods I used to make a mineral thin section slide. The slides are annotated and the descriptions below add details about each slide. If you open the slide presentation in a new window it will be easier to follow the descriptions.
The making of a thin section of Sand
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Slide 1 The most important tool in making thin sections is the flat surface. A glass lapping plate is the most economical base for the various grit papers.
Slide 2 If you live with another person, the second most important tool is a dust collector. In this case, an aluminum roasting pan nicely holds the lapping plate.
Slide 3 Thin brass clips are placed around the slide to act as thickness guides. The strips are in four micron thicknesses. 1 - 200, 2 - 150, 3 - 100, 4 - 50.
During grinding, when the strip starts to wear, you have reached that thickness.
Slide 4 The epoxy bonded sand with a small clothes pin glued on as a handle.
Slide 5 A close up look at the first flat before grinding.
Slide 6 The sand pot first surface has been ground flat and polished and is being heat bonded to the slide.
Slide 7 My home made, low cost hot plate. A $19.00 steam iron set in a frame.
Slide 8 The sand pot is placed on a small block of hardwood and held in place with tape ready for the trim cut.
Slide 9 For a trim saw I used a Dremel rotary tool with a diamond cut off wheel. The idea is to cut as close the slide as possible to reduce the amount of hand grinding.
After the trim, I used a Dremel drum sander to reduce the thickness even more.
Slide 10 The tools used for grinding. The big black holder is used for the coarse grits below 300 grit. More pressure can be used for the coarse grinding and a good grip is needed. The rubber thimble is used for the finer grits requiring less pressure.
Slide 11 The coarse grit holder with the slide and wear guides.
Slide 12 The masking tape on the back of the slide keeps the rubber thimble from sliding around.
Slide 13 A close up of the fine grinding tool and method.
Slide 14 A digital thickness gauge is used for the final thickness measures.
Slide 15 The finished product without a cover slip.
Slide 16 The thin section viewed on edge is approximately 80 microns thick. This is on the outside edge of the proper thickness of 30 microns, but the specimen is transparent with crossed polars.
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Conclusion:
Is it worth making your own thin section slides by hand? Financially, no. I can purchase professionally made slides for less than $10.00. The material costs for the first slide are approximately $75.00. (Lapping plate, polishing grit, sand paper, epoxy)
Is it satisfying? Yes, if for no other reason than it can be done. Time wise, it does not take a long time to make a thin section. The elapsed time is about three hours. This time is actually spread over three or four days. Most of which is waiting for the epoxy to cure. I used heat to accelerate the epoxy cure time. But, like the man who wears suspenders and a belt, I was being cautious and waited 24 hours between epoxy settings.

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mrsonchus
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Location: Cumbria, UK

Re: Making a mineral thin section slide by hand.

#2 Post by mrsonchus » Mon Mar 23, 2015 6:01 pm

Super job this - really like your invention and technique. You're dead right - we don't pursue our passion to save money (within reason of course) we do it because we love it! The production of such a slide as yours is a real, tangible and shareable achievement that has an obvious beauty. :)
Really well done - :) your efforts have made me look at my own (quite different) slides and smile...

Many thanks for this post - your enthusiasm is shared by us all. :D
John B

JimT
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Joined: Fri Oct 24, 2014 1:57 pm

Re: Making a mineral thin section slide by hand.

#3 Post by JimT » Mon Mar 23, 2015 8:16 pm

John B said it better than I ever could. I echo his comments.

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gekko
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Location: Durham, NC, USA.

Re: Making a mineral thin section slide by hand.

#4 Post by gekko » Mon Mar 23, 2015 8:26 pm

Excellent and beautifully-illustrated how-to article! Thanks.

The QCC
Posts: 397
Joined: Sat Oct 11, 2014 10:13 pm

Re: Making a mineral thin section slide by hand.

#5 Post by The QCC » Mon Mar 23, 2015 8:37 pm

Thank you.

CWH

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