fanatic
starting to spend too much on rocks
Member since October 2007
Posts: 233
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Post by fanatic on Sept 11, 2008 12:08:06 GMT -5
Is anyone aware of any instructions, guidelines, advice on slabbing? I'm still saving up for a saw I hope to purchase in the spring. I've collected a bunch of decent rough from various sources and I don't want to mess up good material by making bad decisions. I've heard rumor of a process called "blocking"? I assume there are some guidelines describing how to decide which face and direction to cut first? Any help at all would be appreciated
Thanx Danny
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Post by Bikerrandy on Sept 11, 2008 17:47:57 GMT -5
I always take a slice out of the rock, if I don't like what I see then I simply turn it 90 deg. I've never blocked any of my stones, I use alot of wooden wedges though. Get a brass hammer. After you tighten the vise onto the rock, tap wooden wedges between the rock and vise clamps, tap on the backside of the clamp with the hammer and tighten again. Repeat until you can't tighten anymore. Grab the rock and try to move it. If it moves, even slightly, then start over. A loose rock will cost you a $400 blade!! If I can't find a good flat spot to clamp on to, I'll take the rock over to the workforce saw and make one. Your saw will slow down after using it for a while. Change the oil and flip the blade over. Also, it helps alot to cut up a piece of obsidian. This will refresh your blade. harder rocks such as Brazilian agate will take more time to slab, and put more wear on your blade. (it's worth it) ;D Hmmmm, I'll try to think of more stuff. If you have any specific questions, bring it on!! lol
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Post by Bikerrandy on Sept 11, 2008 17:48:43 GMT -5
Repeat.....wooden wedges!!
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lynskyn1970
noticing nice landscape pebbles
Member since August 2008
Posts: 93
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Post by lynskyn1970 on Sept 12, 2008 9:36:12 GMT -5
i agree i have used wood wedges alot. they really do help out on making the rock more level and stationary in the vise. also bikerrandy is right on the money about the rock moving. you don't want that rock to move one bit. it can come loose and destroy your blade.
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darrad
fully equipped rock polisher
Member since September 2006
Posts: 1,636
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Post by darrad on Sept 13, 2008 8:25:51 GMT -5
I think Randy covered it. I keep my chop saw handy and cut up a 2 x 4 into wedges if I do not have one that is quite right. Also REALLY try to get the rock out of the vise by pulling on it. I sometime have to reset the rock a dozen times before that sucker does not give.
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Post by stonesthatrock on Sept 13, 2008 9:09:50 GMT -5
we do pretty much the samething. Just make sure it in there tight.
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Post by johnjsgems on Sept 13, 2008 14:26:17 GMT -5
Tightening has been pretty much covered. Once you get it secured you want to be able to cut as many slabs as possible without reclamping. Some people cut off an end and glue the rock to a block of wood to slab the entire rock. I wish I could say I've tried this. I leave as much of the rock sticking out of the vise as possible. On my Highland Park that means using blocks in the vise on the opposite side slightly less thick than the rock. Otherwise the vise tilts and never tightens enough. After clamping I back off the crossfeed to clear the blade and push the rock past the blade to set the auto shut off. Then adjust for first slab. I count the crossfeed handle turns to give me the desired slab thickness. Eyeball the last slab and be sure blade will clear the vise jaws. Almost every used saw I see has at least some saw cut in the vise jaws.
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fanatic
starting to spend too much on rocks
Member since October 2007
Posts: 233
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Post by fanatic on Sept 16, 2008 8:31:19 GMT -5
Thanx for the great advice everyone. No doubt I'll have more questions once I actually purchase a saw. I hadn't thought about wedges, but it makes perfect sense. I'm thinking I need to find someone near me so I can gain some hands on experience.
What about types of vises? Does anyone purchase a special one? or just use what comes with your saw? I've only seen pictures, but I've seen what I'll call smooth clamping surfaces and surfaces with teeth as well. Flat or rounded clamping surface?
What is a slab grabber?
John also referred to a system where you can glue the rough to wood? Anyone with experience like to tell me more?
Also, for a saw, I haven't made any decisions and I do have a somewhat limited budget, but I'm strongly considering a 16" Covington. Anyone care to comment?
Thanx!!!!!
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darrad
fully equipped rock polisher
Member since September 2006
Posts: 1,636
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Post by darrad on Sept 16, 2008 20:08:18 GMT -5
Mine is a 16" Covington and I believe Randy (Bikerrandy) uses on as well or at least he did 'cause I asked him a lot of questions before I bought mine. As far as gluing I will carve out a depression in a cut piece of 2 x 4 and glue Thunder Eggs to half them. If I like what I see I slab what I can and the do the same to the other half. It holds and I takes about 3 days soaking in water before the end piece will come out of the wood. Never tried a slab grabber.
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darrad
fully equipped rock polisher
Member since September 2006
Posts: 1,636
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Post by darrad on Sept 16, 2008 20:19:12 GMT -5
I use Elmers glue and Randy uses "one" not "on" I tried to modify the post but that that D*** HTTP 500 internal server error is back. Grrrrrrrrrr.
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Post by akansan on Sept 16, 2008 21:24:24 GMT -5
I just recently started doing the glue route. Right now, I slab as much as I can that is sticking out of the vice. Then I glue the rest of the rock to a 2x4 or 2x6 and slab the remainder. A slab grabber works the same way - it's a vice that clamps on to the very edge of a flat (or mostly flat) surface and allows you to get one or two more slabs out of an end cut without having to glue it onto something.
I've heard the term blocking to refer to a couple different processes. One of them was cutting a 90 degree angle on the stone (one vertical cut, one horizontal) so the stone rests firmly on the bottom and you have a guide for the slab cut. Another process was the act of blocking out larger rough by cutting it down to the size your personal saw could handle. That process involved making sure to capture the patterns you liked on the final chunks to be cut (in other words, don't cut in the middle of the pattern just to make the piece smaller).
I tend to do like others here - cut one way, if I don't like what I see, turn 90 degrees.
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Post by johnjsgems on Sept 16, 2008 21:25:24 GMT -5
A slab grabber is a metal clamp like devise for holding rocks. You basically hold the rock with the clamp and the clamp is held in the vise. Every slab saw I've seen has some type of wood in the jaws. The wood grabs the uneven rock surfaces. My saw is as old as me probably and the hard wood jaws are sometimes too hard to grab. I use soft wood pieces to help grab. Also when cutting geodes I made som three sided pine 1x 4 or 6 open ended rectangles. The geode goes in the open end and the vise holds the wood frame. They get a little shorter every cut but work great and using scrap wood basically free.
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Post by Bikerrandy on Sept 17, 2008 18:50:16 GMT -5
Yep, I still use the 16 inch Covington. It's a keeper! ;D When you purchase your saw, it will come with vise installed. I'm pretty sure that most new saws are auto-feed, it's the only way to go. Also, do you have a trim saw or Workforce yet?
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darrad
fully equipped rock polisher
Member since September 2006
Posts: 1,636
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Post by darrad on Sept 17, 2008 19:35:18 GMT -5
Fanatic - I forgot to mention that I went with the weight feed. Randy says the power feed is fine and I think most prefer it I believe but I wanted more control of the feed. It is a little less expensive but that was secondary. I have not regretted that decision. You do have to pay more attention to the cutting, adding weight and then pulling it out as you near the end of the cut but that is not a problem for me. You can get more blade life this way as well. Dave.
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fanatic
starting to spend too much on rocks
Member since October 2007
Posts: 233
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Post by fanatic on Sept 18, 2008 5:37:14 GMT -5
As expected, lots of great input and advice. I love this forum!
I do have a WF Randy and I've been using it extensively. Pretty much everything I tumble sees the WF first. The learning curve wasn't bad at all.
I'm leaning towards the power feed as it isn't really that much more money.
I think I'll be able to buy a saw in March. Sooner if I have a good fall selling pendants....but thats a LOT of pendants! I got frustrated with ebay and found a guy that literally has a barn full of rough. I visited him a few weeks back and made a pretty hefty investment. Now I have all this beautiful rough and no way to slab it and its driving me nuts! Theres not a lot of rough available in my area - not that I'm aware of anyway. The fellow I visited is over 600 miles away.
Thanx again everyone. I'm sure I'll have more questions leading up to my purchase and even more questions after I start cutting.
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Post by johnjsgems on Sept 18, 2008 8:13:06 GMT -5
When you do get ready to buy look into the powerfeed system. Make sure it is really slow, adjustable or slipping clutch or otherwise kind to the blade when cutting hard rock. Lortone uses a fast feed rate that wipes out blades when the blade gets dull. Weight feed is a pretty good way to go if set up properly as it is infinitely adjustable.
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hope
spending too much on rocks
Member since May 2008
Posts: 477
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Post by hope on Sept 18, 2008 11:37:26 GMT -5
I have been having some problems with my power feed system on a larger, harder rock. I can't seem to get the clutch adjusted correctly. I probably turn it two full turns in one direction to get it to tighten up enough to turn the threaded rod. Then it won't slip. so I start going the other way until it gets loose enough to slip, then it wants to slip all the time and not turn the rod at all. Anyone else have that problem?
Hope
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Post by johnjsgems on Sept 18, 2008 21:18:52 GMT -5
Try dressing the blade. A dull blade may be the problem. There are a lot of blade dressing strings here and a lot of different opinions.
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Post by bobby1 on Sept 18, 2008 22:50:12 GMT -5
Here is a rock gripper that I made. I notch the rock on opposite sides with a dry diamond 5" wheel. Here is a 3/4" thick rock that I wanted to slice parallel to the large flat(ish) sides. Here it is in the gripper. Here it is in the saw. Here are the three slabs that I got from the rock. Here is a Bruneau in the gripper. Here are the slabs that I got from the rough. I use this device for most all of the rocks that I cut. It takes about a minute to notch, grip the rock and clamp it in the saw. The added advantage is that I can orient the rock any way that I want to. There are no precuts to block it out or to try to find how to wedge it in the saw. There are no requirements for wedges either. If anyone is interested in it I can post the materials and dimensions required to make one. The drawback is you need access to a mill to cut the grooves in the jaws. The grip on the rock is very secure because of the leverage you get with the length of the jaws. I use a 3/4" open end wrench to tighten the jaws on the rock. It is a big step up from the commercial grippers that you use wing nuts to tighten it with. Bob
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adrian65
Cave Dweller
Arch to golden memories and to great friends.
Member since February 2007
Posts: 10,777
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Post by adrian65 on Sept 18, 2008 23:01:49 GMT -5
Mr Bob, THANK YOU for posting that device! To me it seems the best grip for rocks I've ever seen.
Adrian
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