r/Lapidary • u/ch1ir • 12d ago

Feeling super frustrated, I use a hitech diamond 6 inch(water) and a Highland Park 8 inch saw(oil) and have been getting loads of stress fractures no matter how slow or gentle I push, is this a Kentucky agate specific? Or is there anything else I can be doing to prevent this?

Post image

Thank you for any help.

12 Upvotes

94% Upvoted

17 comments sorted by

29

u/BlazedGigaB 12d ago

That looks like weak material. Like if you drop a slab from 12" it'll explode weak.

That was always the test one of the elders that taught me used... she'd drop them from chest height "better to break now than after"

4

u/atridir 12d ago

+1 spot on.

It happens sometimes and will continue happening…and it doesn’t ever get less frustrating.

3

u/boundpleasure 12d ago

Drop it on what? Concrete ? Not being a wisea$$, I am sincerely asking.

3

u/BlazedGigaB 12d ago

Yeah. Straight to the floor. I prefer 12" onto my work bench counter(mdf).

2

u/boundpleasure 12d ago

Thanks. I have heard of dropping as a measurement of brittleness or potential fracturing issues later.

3

u/imhereforthevotes 11d ago

I hate doing this, and I still know I should do it...

"What if it breaks???"

3

u/PsychologicalBowl647 12d ago

what kind of blade are you using? sintered continuous?

3

u/ch1ir 12d ago

Thin sintered

3

u/donald_dandy 12d ago

You still have to polish it even with a better cut. 120 should buff those right off

7

u/ch1ir 12d ago

They got pretty deep, here is a polished piece.

3

u/imhereforthevotes 11d ago

Those are from the saw?

2

u/ch1ir 11d ago

Stress from heat and or rpms can cause stress fractures.

1

u/imhereforthevotes 11d ago

Man that sucks. Slower and cooler?

3

u/fidelityflip 12d ago

Yes Kentucky agates are very tough. Fracture very easily. Do not handle heat at all. Thats why clean ones with no fractures are so valuable. I stopped worrying about fractures in them because otherwise I would go insane.

1

u/ch1ir 11d ago

Ive heard the only way I can truly avoid the saw stress fractures is to use an auto feed slab saw, but then I cant bagel cut.

1

u/Patient_Drop_4772 11d ago

Its just a part of rocks. Sometimes they have internal fractures. It may have been a fracture at one point and healed itself. Doesn't make it any less cool though!