Lapidaryforum.net

Gadgets, Gizmos, and Dohickeys => Cutting, Grinding, Polishing => Topic started by: kirigol on May 27, 2016, 01:24:13 AM

Title: How to cut hard materials, which blade ?
Post by: kirigol on May 27, 2016, 01:24:13 AM
Hello,

I've a basic question it seems, but after years I havn't find the right answer.
I use a manual diamond pacific 10 TS saw for 20 years, and have tried different kind of blades such as basic chinese (good result if hardness is less than 6), mk diamond 301, 303, some convington too.
On the automatic Lortone 10", if it's to hard the blade become deformed after 1 or 2 slabs.
In my case it takes hours to cut the hard materials, even in chunk size, such agate, mookaïte, jasper, petrified wood, fossilized coral, chrysoprase and so on... I don't talk about meteorite, gibeon take days to be cut, and not properly =)

So if some people here have recommandation, or tips & tricks, I will be glad to hear you =)
What kind of blade on which material ?
How long does it take in your workshop to cut a 5 sq inch hard agate ?

I thank you in advance !
Title: Re: How to cut hard materials, which blade ?
Post by: Slabbercabber on May 27, 2016, 04:56:51 AM
I've tried both types of MK blades and find them very slow cutting.  Sintered blades take forever.  I now use Chinese blades exclusively but my saws are always modified to use pneumatic feed so my feed pressure is always optimum.  They cut very fast but do occasionally get damaged due to being very thin.  That feature also means less material being turned into rock snot.  Diamond blades should never be used to cut material containing iron (re meteorites).  The carbon of the grit will bond chemically with the iron and fracture out.  For cutting metallic materials you should use carbide blades.  TiC or SiC.
Title: Re: How to cut hard materials, which blade ?
Post by: bobby1 on May 27, 2016, 07:26:42 AM
What kind of coolant/lubricant are you using?
Bob
Title: Re: How to cut hard materials, which blade ?
Post by: peruano on May 27, 2016, 08:47:53 AM
If your auto feed saw is deforming blades when cutting hard material, you may have a feed rate that is too fast for the size, hardness, and shape of your rock and or a blade that is too dull for the job.  My 12" saw has a feed rate of about 1" per 7 minutes, and I'm using the saw blade that I installed over 2 years ago.  I use oil, I make sure my rock is secure, and I let it cut at the sled speed mentioned above with good performance even with just borrowed 1/2 hp motor.  Almost everything I cut is agate, jasper or agatized petrified wood so its hard stuff.  I'd check feed rate and slow or adjust clutch as possible.  Tom 
Title: Re: How to cut hard materials, which blade ?
Post by: johnjsgems on May 27, 2016, 08:58:44 AM
301 and 303C blades cut fast and well for me.  Most complaints I hear are from running blades in wrong rotation.  Diamonds are oriented to cut one way. Blades have an arrow stamped in core.  Lortone is notorious for too fast feed rates. 301 and 303 blades work better at a little faster than "normal" speed.  Recommended speeds and lubricants on Barranca Diamond website.
Title: Re: How to cut hard materials, which blade ?
Post by: kirigol on May 27, 2016, 10:21:16 AM
Hello,
I thank you all for your prompt replies.

So I've a proslicer in stock, I will try if it's better. Otherwise it's the first time I heard about carbide blade (TIC SIC), I'm sorry if I abuse, but could you provide me a link or something like that, my foreign seach engine did not return good answer =)

Regarding the coolant, I mostly use water in the Diamond Pacific, sometime with fuel or rarely with lube cool. In the lortone I put mineral oil only.

I've already think to change the speed rate in the Lortone, but I've to open the part dedicated. I dont know how to proceed, maybe with a potentiometer, or by changing the pulley.
Several searches to do.

In the past I've been surprised by the efficience of the 303, but today I don't know, maybe I'm becoming impatient =)
The trouble I encountered with lubricant is the shipping cost outside US. And in my country when I say I like cutting rock, people just look at me like a Martian =)
It's not really easy to find good tools & supplies at affordable prices.

To have an idea, how long do you spent to cut a 5"x5" agate ?
Title: Re: How to cut hard materials, which blade ?
Post by: Phishisgroovin on May 27, 2016, 08:50:13 PM
i use an old continuous blade for everything.
if it starts cutting slow, i tap the cutting face with a light hammer and make new diamond edges show up so it cuts fast again.
Title: Re: How to cut hard materials, which blade ?
Post by: Redrummd on May 27, 2016, 09:27:25 PM
Phishisgroovin - I think you and I are the only two that sharpen our blades with a hammer.......
Title: Re: How to cut hard materials, which blade ?
Post by: Phishisgroovin on May 27, 2016, 09:42:46 PM
Phishisgroovin - I think you and I are the only two that sharpen our blades with a hammer.......
YOU taught me how to do it! LOL!
See, i pay attention to details!
Title: Re: How to cut hard materials, which blade ?
Post by: Slabbercabber on May 28, 2016, 09:09:31 AM

This type of blade is cheap and runs dry.
http://consumables.alliedhightech.com/Abrasive-Cut-Off-Blades-10-p/10aco.htm
You could also cut them with a metal cutting blade on a bandsaw.
Title: Re: How to cut hard materials, which blade ? hammer the edge!
Post by: olgguy on May 28, 2016, 06:56:33 PM
Thank you, Thank you. PHISHISGROOVIN AND REDRUMMD. I stoned the H out of my blades without much improvement. Have had  A Montana on the saw all day....why not try the hammer?  finished it in 10 min.  There are now three of us.  olgguy
Title: Re: How to cut hard materials, which blade ?
Post by: kirigol on May 29, 2016, 01:37:59 AM
Thank you all for your replies.

I've never heard about the carbide blades, thanks for the link, I had to think about it.

Regarding the hammer's sharpening, why not =)
I usually use a silicone carbide stick for this purpose, but I've an opened mind (I hope so)  =)
Especially if it allows me to cut an agate in 10mn.

Many thanks again for your experiences
Title: Re: How to cut hard materials, which blade ?
Post by: olgguy on May 29, 2016, 06:53:13 AM
The Montana I was cutting had been on the saw most of the day and maybe 3/4 done with one or two hours to go the way it was, after the hammer treatment it only took 10 min. to finish. I could visually see the blade move the cut.
     olgguy
Title: Re: How to cut hard materials, which blade ?
Post by: Redrummd on May 29, 2016, 08:49:10 AM
Remember,  you do not need a lot of force to hammer sharpen - it is more tap, tap, tap, like starting to hammer in a nail rather than actually hammering in the nail. You just hit hard enough to leave TINY pimples in the brass diamond mix on the blade using the edge of a light hammer.  If you chip off a bit of the brass/diamond you are hitting way too hard. I use a hammer with a 6 ounce head....
Title: Re: How to cut hard materials, which blade ?
Post by: sealdaddy on May 29, 2016, 09:23:31 AM
Count me as "four" on lightly hammering the edge to improve the kerf, and speed cutting.
Title: Re: How to cut hard materials, which blade ?
Post by: olgguy on May 29, 2016, 01:29:35 PM
By the way my blade is sort of a thin kerf from Kingsley North's house brand, probably from China and made of steel.
           olgguy
Title: Re: How to cut hard materials, which blade ?
Post by: finegemdesigns on May 29, 2016, 01:33:47 PM
I have the perfect material to ruin your blade. It's called Polychrome Jasper from Madagascar.

Also called Misty Mountain but I think this name came after Polychrome.

This jasper contains the rare element kryptonibladedestyrite which dissolves diamonds on contact.
Title: Re: How to cut hard materials, which blade ?
Post by: kirigol on August 25, 2016, 06:36:26 AM
So...

I've bought a special agate cutter (MK/barranca) to test it... I'm not convinced. I cut an half chunk size moss agate in 20 minutes, ok, but a bruneau jasper in 2hours and half =)
For the meteorite, I had to cut slices in a gibeon siderite, so I've choose a "CBN meteorite blade" which is just a poor 10" Pro slicer. Awful job, I've cut 1 inch in 1 hour and half. The pro slicer was the first blade I've tried 20 years ago, and at this time it was already unable to cut anything (maybe except limonite ;)).
For me it's definitly the worst value blade !

In fact I suppose the best choice is the cheap chinese one, they do the job, if they deform you change, if they stop cutting, hit them with a hammer...
But it's only my opinion...