rxscram
spending too much on rocks
Member since August 2011
Posts: 484
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Post by rxscram on May 10, 2014 1:51:59 GMT -5
Hi All,
Sort of a funny story / lesson-learned to share with you.
I was doing a cut in a piece of Pietersite, when all of a sudden my saw completely stopped cutting... belt squealing, rock jammed on the blade, etc. I was like "dang it! I bent the blade". (There is a ton of diamond left on the sintered edges, so I didn't think the blade was worn out... just that I had damaged it.)
Well, long story short, after a couple of hours of trying various things like reversing the blade, checking alignment, etc., and after ordering 2 new blades off of eBay (they were on a great sale compared to retail!), it occurred to me to dress the blade by running it through a grinding wheel. Did this for a few minutes, then put on the Petey again... cut through it like butter!
So, it'll be an expensive lesson (18" blades aren't cheap, especially the BD-303's), but a valuable one. And... I'll have two extra blades in case something really does go wrong! :-P
Thanks for listening.
Jeff
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,687
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Post by Fossilman on May 10, 2014 8:43:20 GMT -5
I should dress my blade very soon too.............Does any type of grinding wheel work??
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Post by FrogAndBearCreations on May 10, 2014 9:12:41 GMT -5
yes, and also fire brick and obsidian works best for me so I save my obsidian to cut as blade dressing
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rockpowell
having dreams about rocks
Have been rock hunting most of my life, love cutting rocks, have tons of slabs, just haven't posted
Member since February 2013
Posts: 73
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Post by rockpowell on May 10, 2014 9:17:46 GMT -5
ROCKPOWELL Thanks for posting, I agree with you. Dress those blades for better and faster cutting, bring up those diamonds, My 14" Lortone 3 1/2 yrs old has a built in auto dresser where I just put a square stick of silicon in it and push the lever down just a few seconds before the rock hits the saw blade,them release works beautiful the saw blade is a mk 303 and has about 1/16 or less of diamond on it now. It is cutting Cedar Agate like your expression ( like butter ) I do use a surge power bar on the saw, It shut the saw down if there is any flux in the power, saving my saw blade, belts and motor, (4 times now). They say not to use any thing like that,but I do. I am cutting 24/7 with it also have 2 new saw blades, for when the time comes to to replace the old one.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,687
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Post by Fossilman on May 10, 2014 11:22:08 GMT -5
Great,I cut a lot of Obsidian......So I get a two way enjoyment from it than! Thumbs up
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Deleted
Deleted Member
Member since January 1970
Posts: 0
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Post by Deleted on May 10, 2014 11:32:38 GMT -5
actually obsidian wont dress a blade. It will, however, clean a blade. The metal holding the diamonds is harder than obsidian. If you need to wear away metal to expose more diamonds then you need to cut an abrasive hard enough to wear away the sintering metal.
At Larry's recommendation I got a 6" 'medium' grade grinding wheel from Lowe's and have used that to expose new diamonds. I cut thru about 4" of this wheel to dress my 24" blade.
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Post by Rockoonz on May 10, 2014 22:44:56 GMT -5
The dressing sticks are Aluminum Oxide, not silicon Carbide. Silicone Carbide is a structured (sharp) abrasive and can rip the diamonds right out of the matrix on a sintered blade. Aluminum Oxide only removes steel.
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QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,634
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Post by QuailRiver on May 10, 2014 23:29:54 GMT -5
The dressing sticks are Aluminum Oxide, not silicon Carbide. Silicone Carbide is a structured (sharp) abrasive and can rip the diamonds right out of the matrix on a sintered blade. Aluminum Oxide only removes steel. It depends on what type of binder is used. Some of the SC wheels with hard binders will rip out diamond. Especially the SC wheels made for grinding metal. But most of the SC wheels made for lapidary work have a soft enough binder not to rip out diamond. The only exception to this I have found are the greenish colored SC lapidary wheels that Raytech used to sell (not sure who made them for Raytech but they may have also been sold under other brand names too). Those green ones will rip out diamonds and leave a bunch of tiny holes in the edge where the diamonds used to be. I use a lot of old SC wheels for dressing and have never had one of the gray or charcoal colored SC wheels specifically made for lapidary work harm a diamond blade. Larry C.
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rxscram
spending too much on rocks
Member since August 2011
Posts: 484
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Post by rxscram on May 11, 2014 1:11:31 GMT -5
The dressing sticks are Aluminum Oxide, not silicon Carbide. Silicone Carbide is a structured (sharp) abrasive and can rip the diamonds right out of the matrix on a sintered blade. Aluminum Oxide only removes steel. Will this one work? Dressing blade
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Post by Rockoonz on May 11, 2014 13:28:05 GMT -5
The dressing sticks work best IMO
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