tile vs. lapidary diamond blades

[bilquest]

I've got a few piles of jasper and agate rough in the yard. I've cut some of it but found it to be porous. Long story short, I was looking for a way to rapidly dice up the stuff in search of that magical middle that cabs well.

The Harbor Freight 10 inch tile saw caught my attention, mostly for price. Reading other threads on this forum about the speed reduction and whatnot, I decided to utilize my 20% off coupon over at HF and procure the monster. My plan was to outsmart the saw by getting a thin diamond blade rather than the shredding hellions that HF sells. I found a site called diamondbladedealer.com that sells continuous rim, diamond sintered blades that would run on the higher speed saws. I was feeling confident.

I cut my first agate, went through like butter.... zipped another slice off and started feeling that I would make short work over my stacks. Over the next couple slices it went slower and slower. Then it got to take as long as my lapidary blade to get through the stone. I tried dressing the blade with an old paver but probably didn't make enough cuts as it didn't seem to sharpen the blade. Even so, I can't be whacking up 3 pavers for every agate slab... kinda defeats my goal of rapid slabbing.

I have two questions:

1) What is the difference between a tile and lapidary diamond blade (continuous rim)?

2) If I buy the mega-shredder blade from HF, granted it'll cut a wider kerf, but will I have to keep dressing it?

Also, I'll post some pictures of my vise contraption that facilitated nice parallel slabs.

[catmandewe]

The major difference between tile and lapidary blades is the steel used in the blades. The tile blades are designed to run higher rpm and cut softer material.
The lapidary blades are designed to run slower rpms and cut harder material.
If you run a lapidary blade at the higher rpm's it causes the metal in the blade to sluff and cover the diamonds which keeps them from doing their job. Dressing the blade does grind the metal off and expose the diamonds, but if it is a cheap blade they are only diamond coated and you can easily lose all your diamonds while you are trying to dress your blade.
Sintered lapidary blades cost more but have more diamonds and the diamonds are inside the metal so you don't run out of diamond until you actually run out of either rim or blade, depending on how it is made.

Good luck with your saw.
Tony

[Michael S Hoover - Redrummd]

I reverse the rotation direction of my blades after dressing them if they get dull.  I find that really gets them back cutting as I expect.  Also, I find changeing over to cutting a softer stone after cutting a hard agate tends to work a lot like dressing the blade.