[Rockhounds] Color of Minerals (now: need saw blade recommendation)

[Tim]

You are right on the money Don. I learned a few years ago that if you ask
someone who cuts thousands of slabs a year what they use, it's a good idea
to give it a try. I asked John Richardson (who at the time was probably
making well in excess of 10,000 cuts a year with his saws) what blades he
uses and the answer for all blades was MK Diamond
(http://www.mkdiamond.com/lapidary/bld_00.html); for the 18" he uses only
the MK-303. I converted one saw to the 303 at that time and have just
recently converted the other saw as well. John said these blades will
outlast him and I tend to agree; there is NO visible wear on the blade I
have been cutting with for 4 years now (I would guess that I make up to 1000
cuts a year on this saw). I know this because I put the old & new blades
together and the rim looks identical (i.e., is not visibly worn). 

The Meteor blades that I replaced were supposed to be the choice of
lapidaries for a quality blade but in my experience they have all the
problems you mention, plus one really annoying problem, that is if they are
used to cut anything softer than agate or jasper, the media rolls over the
diamond fairly often, which has to be re-exposed by extensive filing and
hammering and/or by cutting something hard and gritty like a grinding wheel.
MK blades never need to be sharpened AFAIK. A Chinese blade would have been
long dead by now (I don't care what they say about their wonderful blades).
Quality control is not the same as the manufacturing process used, using the
correct amount of diamond, the correct media for the diamond, the proper
steel for the blade, thickness, balance, the list goes on...as with
everything else, YGWYPF... I have also noticed that the MK blades are taking
over the market for tile and stone cutting (at least among the pros, who are
no doubt sick and tired of blowing out cheap foreign blades). 

As for using water in any lapidary saw, I stick with what Lortone says,
which is that if you use any water in their saws (with or without additives)
you void the their warranty, period, no exceptions, open bearings or not
(IMO, open bearings could possibly be watertight, if they are designed as
such (boat trailer bearings, for example), but are probably not watertight
if they were not designed to be). I have heard many horror stories from
people who used water, and none from people who had used the lubricants
these saws were designed to use (this does not include such silly lubricants
as peanut or soybean oil). The sole exception would be saws that were
designed to cut with water as a lubricant, i.e. tile cutting or stone
cutting saws, but I know of no lapidary saws of this type (but there may be
a few out there). Using water in a lapidary saw is akin to saying "screw the
manual, I am using oil in my car other than the type the engine was designed
for" and voiding the warranty or risking serious engine damage (yes I know
people who have done this and paid a high price for it).  

Tim Fisher 
Ore-ROCK-On! 
Email address at http://OreRockOn.com

-----Original Message-----
From: rockhounds-bounces at lists.drizzle.com
[mailto:rockhounds-bounces at lists.drizzle.com] On Behalf Of DonH
Sent: Tuesday, March 17, 2009 8:21 PM
To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors
Subject: Re: [Rockhounds] Color of Minerals (now: need saw blade
recommendation)

Kris Rowe wrote:

> I'm currently converting an 18" saw from oil lube to water. Thankfully,
the
> saw is equipped with greasable bearings, rather than sealed, and can be
used
> with water. A full circulation and filtering system is being installed and
> will hopefuly work! (Mumbling my prayers ...)
> I'd love to get some opinions and recommendations on blades for this saw
> before spending the precious dollars. What say you, dear list members? Buy
1
> top quality (expensive) blade, or start with cheap import blades and
simply
> replace more often?


Greetings!

First, by way of helping out, notice that I modified the subject.  You 
will definitely find on this list that not everyone reads every thread, 
and if you need help with a specific thing, it's a good idea to post a 
new message with a new subject... in this case, it would have been good 
to say "help needed with 18" saw blades."  There are several people on 
this list who have quite a bit of related experience!  I hope this logic 
makes sense and it is helpful to you in the future.

Now, as far as blades, my experience is limited to 10" and less. 
However, I can say with certainty that I have always received what I 
paid for.  Now, I can't compare dollar-for-dollar and brand-for-brand, 
but in general, as groups, the name brand and more expensive blades 
perform better, last longer, and warp less than the cheaper ones I have 
bought.

However, I can also say that quality control in developing countries 
such as China and India is improving by leaps and bounds.  It may well 
be true to that a Chinese blade of a certain edge style and kerf, though 
costing 1/3 less, may perform as well as one of the big names.

The way to find out is easy, but will take some time.  That is, order an 
economy blade of your choice, perhaps one recommended by another list 
member.  Keep track of how many inches of rock it cuts before you need 
to discard it.  Then do the same by purchasing a more expensive blade.
Compare the per-inch average cost of each blade.

I cut hundreds of pieces of basalt and granite in the last 3 years, 
using a 5" water-cooled blade, and I chewed through several of them. 
When I bought the more expensive ones, they cut faster, lasted longer, 
and dished less.

As far as converting your saw to water-cooled, others will need to 
advise on that.  All I can say, is be careful.  Also, I know from using 
a few water-cooled saws that it is good to use an anti-rust additive.  I 
also use distilled water, but I developed that habit when I lived in a 
place where the well water was brown and full of flavor.

Good luck,
Don




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