Post by deb193redux on Aug 21, 2011 22:35:25 GMT -5
Several folks told me about blocking large rough with angle grinder that is set up with a saw blade. Make a notch and then use a chisel.
I decided to give it a try when Harbor Freight put a 7" grinder on sale and then I also had a 20% off coupon. Unfortunately it uses 7/8" arbor holes, and all of my 7" blades are 5/8". So I had to go to Ace hardware and get a 7" MK Diamond masonry blade with 7/8" arbor.
Then I had to rig up a water supply. I clamped my hose nozzle onto a truck dolly that I pushed next to my work table (aka, a board on two saw horses in my driveway.)
Here are some pics of the 1st rock I did, an the water, and the grinder, and the notch I cut, and then the split with the chisel. (I don't have a pic of me using the grinder because nobody was here to take one for me.)
![](http://rocktumblinghobby.com/pb/IMG_0299-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0300-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0301-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0304-1.jpg)
It went pretty well. The blade did not bind up in the cut, and the water was easier to manage than I feared, and the rock split with the 1st wack of the hammer/chisel.
So, I continued to notch the rock and split off pieces until I had a bunch of pieces that would fit in either my LS12 or the LS10 saw.
![](http://rocktumblinghobby.com/pb/IMG_0306-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0307-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0309-1.jpg)
There is still one big chunk. I figure to slab the pieces I blocked and then come back to the big chunk if the rock proves to be worth the effort.
The blade had dulled and rounded a bit after cutting up that 1st rock, so I cut up a fire brick to expose more diamonds. It worked pretty good, so I cut a slice of brick between each rock for the rest of the day.
Then I blocked a piece of 4" thick tigereye, a large hunk of red-yellow-green jasper, a 5" cube of Rocky Butte that I had blocked using the 20" saw at the Salem club when I lived in Oregon - but it was still too big for my LS12, so I made 2 pieces.
![](http://rocktumblinghobby.com/pb/IMG_0310-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0311-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0313-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0314-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0316-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0318-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0319-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0320-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0321-1.jpg)
I decided to try a really large rock before I quit, so I got a piece of Rocky Butte that was bigger than a bowling ball. It was difficult to make notches deep enough, so the chisel and hammer did not make the pieces exactly as I wanted. But, it did give me some control over breaking up this stone. I got to roughly position the pattern the way I wanted it.
![](http://rocktumblinghobby.com/pb/IMG_0322-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0323-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0324-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0327-1.jpg)
I took several breaks, and was also feeding my slab saws, but I spent about 4 hours to set up and block the 5 rocks. Not a bad days effort.
![](http://rocktumblinghobby.com/pb//IMG_0329-1.jpg)
The blade shows a lot of wear. It is over half used up. I think I will get a bit better at being a little more gentle, but I think about 7-8 rocks may be the limit. It is a $27 blade, so that is about $5.50 per rock. I think this compares favorably with paying a few dollars per cut on a 20" or 24" saw. I will be on the lookout for cheaper blades, but I trust MK to put enough diamonds, so I will not go too cheap or too thin.
![](http://rocktumblinghobby.com/pb/IMG_0330-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0331-1.jpg)
Anyway, the method seems to work pretty good, and a cheap angle grinder seems adequate. You can make deeper notches by spending a little more to get a 7" grinder. If you do this make sure your grinder is plugged into a GFI outlet because of all the water and not wanting to get electrocuted.
I think I will make a plywood box with sides to control spray (my car got a rock snot bath). I also want to rig a vise on the bottom of the box because the big stones stay put, but the medium ones move around while you are trying to make the notch. Also, I think I can improve the water supply by putting a post on side of the box and maybe getting some positionable tubing.
ADMIN EDIT - repaired broken images, original code below
--------------------
I decided to give it a try when Harbor Freight put a 7" grinder on sale and then I also had a 20% off coupon. Unfortunately it uses 7/8" arbor holes, and all of my 7" blades are 5/8". So I had to go to Ace hardware and get a 7" MK Diamond masonry blade with 7/8" arbor.
Then I had to rig up a water supply. I clamped my hose nozzle onto a truck dolly that I pushed next to my work table (aka, a board on two saw horses in my driveway.)
Here are some pics of the 1st rock I did, an the water, and the grinder, and the notch I cut, and then the split with the chisel. (I don't have a pic of me using the grinder because nobody was here to take one for me.)
![](http://rocktumblinghobby.com/pb/IMG_0299-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0300-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0301-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0304-1.jpg)
It went pretty well. The blade did not bind up in the cut, and the water was easier to manage than I feared, and the rock split with the 1st wack of the hammer/chisel.
So, I continued to notch the rock and split off pieces until I had a bunch of pieces that would fit in either my LS12 or the LS10 saw.
![](http://rocktumblinghobby.com/pb/IMG_0306-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0307-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0309-1.jpg)
There is still one big chunk. I figure to slab the pieces I blocked and then come back to the big chunk if the rock proves to be worth the effort.
The blade had dulled and rounded a bit after cutting up that 1st rock, so I cut up a fire brick to expose more diamonds. It worked pretty good, so I cut a slice of brick between each rock for the rest of the day.
Then I blocked a piece of 4" thick tigereye, a large hunk of red-yellow-green jasper, a 5" cube of Rocky Butte that I had blocked using the 20" saw at the Salem club when I lived in Oregon - but it was still too big for my LS12, so I made 2 pieces.
![](http://rocktumblinghobby.com/pb/IMG_0310-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0311-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0313-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0314-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0316-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0318-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0319-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0320-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0321-1.jpg)
I decided to try a really large rock before I quit, so I got a piece of Rocky Butte that was bigger than a bowling ball. It was difficult to make notches deep enough, so the chisel and hammer did not make the pieces exactly as I wanted. But, it did give me some control over breaking up this stone. I got to roughly position the pattern the way I wanted it.
![](http://rocktumblinghobby.com/pb/IMG_0322-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0323-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0324-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0327-1.jpg)
I took several breaks, and was also feeding my slab saws, but I spent about 4 hours to set up and block the 5 rocks. Not a bad days effort.
![](http://rocktumblinghobby.com/pb//IMG_0329-1.jpg)
The blade shows a lot of wear. It is over half used up. I think I will get a bit better at being a little more gentle, but I think about 7-8 rocks may be the limit. It is a $27 blade, so that is about $5.50 per rock. I think this compares favorably with paying a few dollars per cut on a 20" or 24" saw. I will be on the lookout for cheaper blades, but I trust MK to put enough diamonds, so I will not go too cheap or too thin.
![](http://rocktumblinghobby.com/pb/IMG_0330-1.jpg)
![](http://rocktumblinghobby.com/pb/IMG_0331-1.jpg)
Anyway, the method seems to work pretty good, and a cheap angle grinder seems adequate. You can make deeper notches by spending a little more to get a 7" grinder. If you do this make sure your grinder is plugged into a GFI outlet because of all the water and not wanting to get electrocuted.
I think I will make a plywood box with sides to control spray (my car got a rock snot bath). I also want to rig a vise on the bottom of the box because the big stones stay put, but the medium ones move around while you are trying to make the notch. Also, I think I can improve the water supply by putting a post on side of the box and maybe getting some positionable tubing.
ADMIN EDIT - repaired broken images, original code below
--------------------
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0299.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0300.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0301.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0304.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0306.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0307.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0309.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0310.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0311.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0313.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0314.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0316.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0318.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0319.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0320.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0321.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0322.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0323.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0324.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0327.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0329.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0330.jpg[/img]
[IMG]http://i207.photobucket.com/albums/bb114/deb193/rough/blocking1/IMG_0331.jpg[/img]