Which belts to buy?

PetrifiedWood

Well-Known Member
I finally got my belt grinder situated, and now I'm looking to get a good selection of belts.

What I'd like to know is which type of belt offers the best value. I don't mind paying twice as much for a belt if it's useful life is more than twice as long as a lower priced belt.

And I'm also wanting to know which grits to buy, and which grits you use the most.

Through a lot of reading here and elsewhere I've learned that my Grizzly grinder has a reputation for running very fast. So I think I'll want to start with 80 grit instead of 40 so I don't remove too much metal at first.

I'd like to know which grits get used more than others so that I can buy appropriate amounts.

I'm figuring I want to buy a minimum of 3 belts in each grit, but if I'll be using twice as many 220 grit belts (for example), then I'd like to buy 6 of those instead of three. I think I read somewhere that some of the finer grit belts don't last through as many knives as the coarse grit belts, but I want to be sure before I place an order.

Thanks for all your help so far, this place has been a tremendous resource! :)
 
The belts that you will use the most will be the ones that you establish the profile and bevels with. That usually the coursest grit. The next coursest will refine the profile and beves but will primarily just refine the scratch pattern. You will probably return to it after heat treating to to remove fire scale. After that you will just be refining the scratch pattern. How fine of a grit you will go to will depend what type of finish you want to apply. For a satin finish I go down to about 400 grit the go to a Scotch-Brite belt. If you wanted to do a mirror finish you might want to go out to 800 grit before switching to a buffing wheel.

The first grits should be made with rather agressive abrasives like a ceramic. The last belts should be of a material that is less agressive.

Doug
 
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Near the bottom of page 3 of this sub-forum there is a thredd "which belts to buy", or something like that. with substantive replies. Personally, I use a 60 grit for primary bevel grinds so I use those the most. Usually I use a 120 after that. I also use the flexible 400 grit. But I had to "borrow" my friend's 36 grit the other day for some handle work- aluminum scales. The problem is, and I live in the Chicago area, there is no retail outlet where you can just stop in and buy 72x2 belts. And worse, I'm too cheap to order a bunch at once, so I'm always running out or using belts beyond the point where they are effective, which just builds unneccesary heat on the blade, and adds forever to getting the job done while your hands and arms are getting tired and more likely to grind where you don't want to.

I would get a few 36's for hogging unwanted steel while profiling and handle stock. I've read that the 36 grit run cooler than finer grit. As to taking off too much, maybe just apply less pressure if you want to remove less? A lot of makers run there grinders full bore. I read the Delbert Ealy, who is well known for his damascus and makes excellant razor thin chef's knives grinds at full speed because that's how he learned. He told me that he uses a 36 grit belt on his chef's kinves for the primary flat grinds after the steel has been heat treated, in part because the 36 grit grinds cooler and won't effect the temper.
 
Everybody has their own combination of grit/belt type that works best for them. The best advice I can give is try a few of each type and grit and decide what works best for you. I too own a Griz and the only real control you have is pressure. The Griz has a pretty steep learning curve but I think learning on one will make you a better grinder if and when you get something better. Having said all that this is what works best for me. Blaze in 36 or 40 for hogging and profiling. Blaze 50 & 120 for establishing bevels and pre- h/t on carbon. Post h/t on carbon I go back to a 50 or 120 depending on steel and blade type then go to a 45 micron gator then a 30 micron gator, from there I go to a scotchbrite for a belt finish or hand sand. On air hardening steel I use the same order but go all the way to the desired finish and clean it up after H/T. The Blaze, Gators, & Trizacts are a little higher but well worth it in my opinion. You will be amazed at how long the Gators & trizacts will last. They will grind all the way to the belt. If they slow down push a 2" wide piece of steel against the flat platen with a lot of pressure and it will expose new abrasive and bring it back to life. Sometimes turning them around will help too. The only thing I don't like about them is you can't get them wet, if you do the abrasive will just fall off. Some plain old A/O belts in the coarser grits are handy for handle material. Again this is just what works for me. Hope it helps.

Best Regards,
Darrin
 
Read BossDog's tutorial; it's an excellent primer.

As you progress, you will think of more ways for belts to be used.
Take into consideration the abilities of your machine. (Not referring to your specific machine, just in general.)


For metal removal, I would certainly use the ceramics.
Progressing to metal finishing, the engineered (structured) abrasives seem to last forever.
For profiling of handle material, I use the cheapest AO belts I can find.

Finally, be sure to incorporate a supply of quality sandpaper. Personally, I would let sandpaper take precedence over fine-grit belts if I did not have the money for both up front.


Rob
 
Thanks for all the responses. I apologize for starting a new thread, considering there is an existing one already going!

Anyhow, I live in a very small town and there aren't any places locally that carry 2X72 belts here either. The only belts you can find are ones for the hand held belt sanders, and the 4X36 variety.

I did read the tutorial on USA Knifemaker supply website about choosing belts and that's what got me thinking about it. I want to make sure I buy enough of them and in the right proportions so I won't get stuck waiting on shipping.

Another belt related question, should the belt "ride" the platen, or should there be a bit of space between the back of the belt and the platen surface? On my grinder, the tracking wheel gives the belt a slightly rounded shape so it bows outward a bit and contacts the tool rest if I set the tool rest to the recommended minimum 1/8" from the platen. But if I bring the platen and tool rest forward so the belt rides the platen a bit this isn't as big a problem.

Also, I'm wondering if I should make a new surface plate for the tool rest that would overhang the belt on either side to help prevent workpieces from getting pulled down between the belt and the tool rest.
 
I set my platen so the belt rides on it. But I have a KMG platen which is a different set up. It has a small "roller wheel" right above and below the platen and if your holding the blade vertically those wheels tend to grind unwanted gouges in the blade. If you use stiffer belts and you have to push the blade/belt to the platen you may get a distorted, i.e. non flat grind.

One thing I should get is the ceramic (glass) liner for the platen. USA Knifemaker supply sells them. I was surprised that in a fairly short time I deformed the platen...wore a grove in it from the backside of the belts.
 
I set my platen so the belt rides on it. But I have a KMG platen which is a different set up. It has a small "roller wheel" right above and below the platen and if your holding the blade vertically those wheels tend to grind unwanted gouges in the blade. If you use stiffer belts and you have to push the blade/belt to the platen you may get a distorted, i.e. non flat grind.

One thing I should get is the ceramic (glass) liner for the platen. USA Knifemaker supply sells them. I was surprised that in a fairly short time I deformed the platen...wore a grove in it from the backside of the belts.

Yeah, I have been eyeing the glass liners, and have read some about folks using ceramic tiles too. I guess I should see how it goes with the existing platen first. There's this "stuff" on mine that Grizzly calls "graphite" and it has been flaking off all over the place into little shiny round flakes that look like shotgun powder. I imagine I'd need to peel that off to apply the glass.
 
Yeah, I have been eyeing the glass liners, and have read some about folks using ceramic tiles too. I guess I should see how it goes with the existing platen first. There's this "stuff" on mine that Grizzly calls "graphite" and it has been flaking off all over the place into little shiny round flakes that look like shotgun powder. I imagine I'd need to peel that off to apply the glass.

Yes I think you could always add the liner. Do you have a home supply store near you where you could buy some soft steel, 3/16" x 1 1/4" or so. If so you may want to play with some of that to see how you want to set the grinder up and get used to how it grinds. A lot of folks use the soft steel to make patterns for knives that they want to repeat and that would be a good application for the practice.

Are you contemplating flat or hollow grinds for the knives?
 
Add the glass platen you wont regret it. To install it clean the steel platen down to bare steel, have it sandblasted with the coarsest A/O you can get, then JB weld it to your platen. Once its cured install it so it just touches the belt then go about another 1/8" - 3/16" and tighten it down. As far as the tool rest I just put a coarse belt on and pushed the tool rest into the platen until about a 1/4" deep notch was formed. This cuts down on thin blades being jammed between the tool rest and platen. Again this just what works for me.
 
Yes I think you could always add the liner. Do you have a home supply store near you where you could buy some soft steel, 3/16" x 1 1/4" or so. If so you may want to play with some of that to see how you want to set the grinder up and get used to how it grinds. A lot of folks use the soft steel to make patterns for knives that they want to repeat and that would be a good application for the practice.

Are you contemplating flat or hollow grinds for the knives?

I'm not planning to use any hollow grinds to be honest. I think most of my stuff will be flat or convex and the occasional Scandi grind. I like the idea of practicing grinding on mild steel. I guess it's cheap enough anyhow, and I would like a repeatable pattern for profiles I'm happy with.

Add the glass platen you wont regret it. To install it clean the steel platen down to bare steel, have it sandblasted with the coarsest A/O you can get, then JB weld it to your platen. Once its cured install it so it just touches the belt then go about another 1/8" - 3/16" and tighten it down. As far as the tool rest I just put a coarse belt on and pushed the tool rest into the platen until about a 1/4" deep notch was formed. This cuts down on thin blades being jammed between the tool rest and platen. Again this just what works for me.

I was really tempted to do that with the tool rest myself! I also think the platen bracket on my machine is bent to a slightly more acute angle than 90 degrees because the tool rest has a bigger gap on one side than the other against the platen, but the tool rest is square to the drive wheel. I want to get that bent to a perfect 90 degrees before I notch the tool rest. And I think the platen being out of square is causing tracking issues too. it's just another of those bugs that needs to be worked out. I still have to figure out where to mount my vise again in order to bend the bracket. I had to move it to make room for the grinder.

Here's a short video of my shop setup so far... It's modest, but it's what I have. :D

[video=youtube;e0PwaCPcIzw]http://www.youtube.com/watch?v=e0PwaCPcIzw[/video]
 
That's a great video. I had to make my tool rest because I made the GIB kit sold by Polar Bear Forge. My tool rest is 4"x6" (my own choice) and its too small. neither deep enough nor wide enough.
 
That's a great video. I had to make my tool rest because I made the GIB kit sold by Polar Bear Forge. My tool rest is 4"x6" (my own choice) and its too small. neither deep enough nor wide enough.

Thanks! Did you notch your tool rest as well?
 
I've attached a picture of my rig with the too small tool rest and a picture of Michael Kantor's MAP arm (articulating tool rest.) Unfortuneatly this won't work with your grinder or mine, but it gives you an idea of a good sized tool rest.

IMG00013-20110312-1019.jpg
map arm 2.jpg
 
I've attached a picture of my rig with the too small tool rest and a picture of Michael Kantor's MAP arm (articulating tool rest.) Unfortuneatly this won't work with your grinder or mine, but it gives you an idea of a good sized tool rest.

View attachment 24328
View attachment 24327

Thanks for the pics. Yeah that grinder in a box looks like a solid piece of equipment. Funny thing is I had to decide whether to spend my money on a mini milling machine, or a grinder and heat treat oven. I opted for the grinder/oven, but now I can see that eventually a milling machine will come in really handy too for making parts for the other tools. I'm just afraid I will need a bigger shop too!

I still have to get a 220V outlet and wire up a circuit for the oven too. But I'm waiting until it gets here because the local home improvement store has about 6 different 220V outlets and I want to be sure I buy the right kind.
 
Well, I wound up getting some Norton Zirconia Alumina belts in 80, 120 and 220 grit to get started with. They are supposed to show up today.
 
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