darrad
fully equipped rock polisher
Member since September 2006
Posts: 1,636
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Post by darrad on Feb 20, 2008 21:21:24 GMT -5
Hi all, My 16" blade is cutting pretty slow. I think a dressing stick is the way to go to bring it back to life a bit. It has about 90 hours on it. I cut slow (1" per hour) and most have been in the 4"-5" thick range. but I have a couple of questions. #1 is this the best way to go? Is there a rock that will do the same? It seems to me cutting 220g SiC could ruin a blade pretty fast. Which leads me to question #2 If this is the best way how much do you cut the stick without causing damage to the blade? I am looking at one from Covington which is 6"x2"x1" This might belong in the slab saw thread but I aint sure since it is about dressing sticks. Any comments, advice, opinions will be greatly appreciated. Thanks in advance. Dave.
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Post by johnjsgems on Feb 20, 2008 22:01:43 GMT -5
The purpose of the dressing stick is to wear away the softer matrix material to expose new diamond. Once the diamonds are worn down cutting gets very slow. You won't hurt the blade by dressing. If you plan on using a 220 SC I'd cut through the block (a thin slice) maybe twice. Barranca has the best deal going in dressing sticks. Their stick is 60 grit Aluminum carbide, 8" x 2" x 1" and only $6. One slice should do it. I use broken pieces of cinder blocks in my bigger saws. Works fine and costs nothing.
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Post by captbob on Feb 20, 2008 22:22:13 GMT -5
Hi Dave, I hope that you don't mind a slight hijack of your thread, but I'm seeing a chance to learn something here.
(just when ya'll had hoped I was out of stupid questions!)
How do you know when your saw is cutting slow? Doesn't it HAVE to cut at the rate the vise/carriage is feeding the rock?
I've read that turning the saw blade around can help. Does it and is that worth the trouble?
How would I know when it's time to dress the blade or even if it's cutting slow?
And, just for Dave... your saw cuts at 1" per hour? Seriously?
Thanks for any schoolin' for this newbie saw owner!
Edited to add: Do smaller saws cut slower than larger ones?
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Post by catmandewe on Feb 20, 2008 23:14:24 GMT -5
If you are using an automatic feed system, you will notice more saw marks as your blade gets dull. A good sharp blade will make a smooth cut. If you are using a weight feed system, a dull blade will actually slow down the cut.
My big saw will cut at almost twice the rate my little saw will (30" vs 16") so I think a bigger saw will cut faster, although the big saw is a weight feed system and my little saw is an automatic feed system, so the little saw will never speed up. The slower your saw cuts, the longer the blade will last.
I use a fire brick to sharpen my saw blades, works good.
I have read numerous places that if you turn your blade around you will shorten the life of the blade, because as you turn in one direction, you wear matrix around the diamond, which makes a small sand dune like hill behind the diamond, that helps hold it in place until the diamond wears out or falls out. If you turn your blade around you wear this "sand dune" away and all the diamonds which are still supported by the sand dune will fall out. You will expose new diamonds this way, but at the expense of that layer of diamonds that gets lost when you turn it around, hence shortening the life of your blade.
Thats my story and Im stickin to it.....................Tony
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darrad
fully equipped rock polisher
Member since September 2006
Posts: 1,636
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Post by darrad on Feb 21, 2008 0:09:39 GMT -5
Captbob, It's weight feed and I keep the weight at a point that is the speed it cuts to preserve the blade life as long as possible. The things aint cheap. It went from 1" per hour to 1/2 - 5/8 per hour as I was cutting a chunk of Mook so I knew it needed dressed.
Tony - I heard the same thing about about turning the blade around from a couple of folks at my local rock club.
John- Do you sell the sticks? Sent you a PM. Dave.
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lsmike
spending too much on rocks
Maxwell's demon lowers tumbling entropy
Member since January 2007
Posts: 468
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Post by lsmike on Feb 21, 2008 10:56:07 GMT -5
Stonewizard:Serendippity!See my post of yesterday under Lap. Tips.Mike.
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Post by johnjsgems on Feb 21, 2008 12:21:54 GMT -5
1" per hour. Don't you spend more on electricity than you would on blades?
As far as reversing, 303 blades are directional and notched rims are not. I can't see an advantage to turning one around. If it is cutting slow you are trying to cut with the softer matrix material. Dressing (with bricks, blocks, or dressing sticks) is the sensible answer to me.
Dave- yes I do.
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