Hi Travis,

The belts that you ultimately wind up using will be a combination of what you find works best for you in your shop and what you get used to using . There are a lot of good belts out there that I have not tried, because I have I have developed a grinding style that works with the belts that I have used for a long time. I encourage you to experiment with different belts to find what you like best. Below are the belts that I use.

For rough grinding, I use 3M 967F belts in 80 grit. I heartily recommend these belts for your rough blade grinding. They last a long time and cut aggressively. They also track very true on my grinder, without shimmy. This helps you to cut cleaner plunge lines. Use these belts ONLY on steel. The grit matrix is not suitable for soft materials and will load quickly if you try to use them on handle material. Because of their aggressive cut rate, I am able to use a finer grit for rough grinding (80G) and eliminate one or two grit progressions. From the 80G belt, I change to a 320G belt to finalize my rough grinding.

For rough shaping of handle materials I use Klingspor CS411 belts in 60 grit.

The finer grit belts that I use are Klingspor LS 312 abrasive with J-flex backing. I have belts in 120 grit, 220 grit, 320 grit and 400 grit. I use these belts for both blade steel and handle grinding.

Another LS 3212 belt that I use is the 1 inch scalloped edge belts. These are great for getting into concave areas, like behind the guard on a hunter to finish the junction between the guard and handle material. The scalloped edge allows the belt to roll smoothly around the curve without cutting a groove into the material. I have these in only 320 grit and find that this one grit suits all of my needs for this type of belt.

I use 3M Trizact belts in A100 grit for rolling the convex edges on my blades. I like these belts for this purpose because they are stiff enough to run flat and give me a predictable cut. I find that more flexible belts (like J-flex back) tend to cup as they run and make it difficult to tell where they are contacting the blade.

I have an assortment of other belts in my shop that get occasional use. I have some Scotch-Brite belts that come in handy for some things. I think these belts in fine and ultra fine are most useful. I also have several grits of silicon carbide abrasive belts that I use for mammoth tooth material.

The most important thing to understand about belts is when to throw them away. Belts are expensive and we all try to get our money's worth out of them. But, using a worn out belt is a waste of time and will only cause you to have difficulty with your grinding. A worn belt will not cut predictably and cause you to have difficulty making a clean grind. You will find yourself struggling to make the grind as you want and you will spend unnecessary time trying to get the work done. Plus, you could wind up ruining your piece because the belt isn't cutting where and how you expect it to. If you are using a belt that has some time on it and you start having trouble with your grind, put a new belt on. You will likely find that the problem is with the belt and not with your grinding skill.

You didn't mention what type (brand) of grinder that you have. Grinders are a whole 'nother subject and there is much to know about how they affect the quality of your grinding. I have a KMG grinder. It has been squared and accurized to make precise and predictable grinds. I have built custom platens for it, made a number of modifications to it and built special attachments for it. This would be a good subject for a "How To" post.

Steve,

Thanks for the reply and answering my questions about the belts it was very informative. I plan on trying out some different types but allot of the ones you listed are on my list to try. I think you provided a good baseline for me to go off of. In regards to what grinder I am using it is a Burr king 960-272, I like it allot but am not very proficient yet. When I was picking the grinder I wanted I was somewhat limited because of my current duty location and shipping restrictions, and Burr King was very helpful with the process. You point about not knowing when a belt is bad is a good one I have a very hard time telling when I should switch belts.

Travis,

Dan had asked me to reply to your question, but I see Steve's beaten me to it! There is no better example of Steve's point that everyone will finally choose which belts suits his own grinding style and experience than to say that I'm going to try the 3M 967F's Steve uses, to see if I like them, and can go up a grit on my initial grind, as he suggests. If so, your question has already been valuable to me, and "Thanks Steve!"

Currently, after much prior experimentation, I use Norton R980SG Blaze Ceramic in 50 grit, and go to Klingspor RB406JF, in 120 and then 220. I get these from Tru-Grit.

As somewhat of a professional "sander", (I used to do linear polyurethane paint-jobs on boats, and sand 4 and 500 square feet of hull surface per job), I can strongly echo Steve's advice to grind with a sharp belt. It's difficult to tell you over the internet what "sharp" means, but in the case of the Norton 50 g that I use, a new belt will rough grind two 6 inch hunters, or one 10 inch bowie, before being shifted to shaping guards, etc.

Welcome to a fun avocation, and to the ABS forum.

John White

John,

Thanks for the welcome and the reply I appreciate it. I have a few Norton Blaze Ceramic in 80 grit, but I think I want to try the 50 grit to see how much of a difference there is. Next time I get a chance I think I am going to order some of the ones Steve mentioned and see how that goes.

Travis

Travis,

One thing that I forgot to mention is how to remove the forge scale from your blade. Forge scale is extremely hard and will quickly dull a grinding belt. I use a side grinder to remove the scale. I have both 4" and 7" side grinders. The typical grinding disc works well, but better yet are snagging wheels. The wheels last much longer than the discs. You can get snagging wheels from MCS Industrial Supply. Get a snaging wheel to fit your side grinder and use it to remove the forge scale before going to the belt grinder with your blade.

As for recognizing a dull belt; you can feel the grit on the belt as compared with the feel of a new belt to get some idea of how dull it is. The best way though is the appearance of the steel that you are grinding. A sharp belt leaves a flat, less reflective finish on the steel. A dull belt begins to polish the steel and leaves a shiny surface. Again, a little experiance helps with knowing what to look for.

Steve,

I did not think about the scale being harder thanks for the tip. I did notice my belts not lasting as long when I used them to remove it I guess I just wasn’t putting 2 and 2 together. I placed an order for some belts the other day I’m eager for them to arrive so I can try them out. Thanks everyone for the advice.

Travis

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Travis,

One thing that I forgot to mention is how to remove the forge scale from your blade. Forge scale is extremely hard and will quickly dull a grinding belt. I use a side grinder to remove the scale. I have both 4" and 7" side grinders. The typical grinding disc works well, but better yet are snagging wheels. The wheels last much longer than the discs. You can get snagging wheels from MCS Industrial Supply. Get a snaging wheel to fit your side grinder and use it to remove the forge scale before going to the belt grinder with your blade.

As for recognizing a dull belt; you can feel the grit on the belt as compared with the feel of a new belt to get some idea of how dull it is. The best way though is the appearance of the steel that you are grinding. A sharp belt leaves a flat, less reflective finish on the steel. A dull belt begins to polish the steel and leaves a shiny surface. Again, a little experiance helps with knowing what to look for.

You got that right!! I always get rid of the scale first, always. I sandblast it off. Alternately you might consider immersing the blade in muriatic acid for about an hour. It's a nasty procedure and ideally should be done out doors as the fumes are very bad to breathe and will rust your tols as well; BUT it will absolutely clean a blade of scale.

I use the klingspor products too. For real fast, aggrssive metal removal though, I prefer the 36 grit belts, the blue ones; I believe they're zirconium oxide?

If you are not in a hurry vinegar will knock the scale off also. Takes about 24 hours. It actually might take less time, but that's how long I leave them in.

Bob

Travis:

I asked Dan Johnson to answer your question on grinding belts. Dan Johnson is an Honorary Member of the ABS, owner of Stephen Bader &Co, and a recognized expert on abrasive belts.

Dan Cassidy

Forum Administrator

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Travis,

Dan Cassidy asked me if I might try to offer a few suggestions in answer to your question regarding belts. In the process I will stray from your specific subject with some additional suggestions which I feel are important for a new maker to consider. Please understand at the outset, I am neither a knifemaker nor a bladesmith. I have, however, been in the business of building abrasive belt machinery and supplying belts to a wide variety of industries for just over 40 years. I am an honorary member of the ABS.

Belt selection can be a daunting process for the new maker, particularly when he is located in an area where his choices are somewhat limited. Please excuse me if I assume that you are a complete novice. By doing so I hope to be able to suggest to you the steps which I believe will help you in determining which belts will best fit your needs both now and in the future.

The first essential step is to be sure that your machine is set up properly. It is important to plan your machine height, not just place it on whatever table or stand happens to be available. My suggestion for finding the proper machine height would be grip a blade in your hands as if you were grinding it and stand in a comfortable position in front of the machine with your feet positioned to give you maximum stability with your forearms parallel to the floor and your elbows snug to your sides. Now measure the height from the center of the blade to the floor. That should be the height of the horizontal centerline of your contact wheel give or take and inch or so. A grinding point that is too low puts undue strain on the back and one that is too high places more strain on the wrists. Proper grinding height better allows you to use your body for support and will help reduce fatigue. This is not to say that you can’t make a quality knife if your machine is not in this position. God knows that there are lots of master craftsmen out there whose machines are nowhere near this suggested height. All I am suggesting is that proper machine height may well speed your skill development and reduce the fatigue factor.

The next step is to grind away on any old piece of steel. The object here is to get over the natural fear of the machine and to feel comfortable delivering good firm controlled pressure against that contact wheel or platen. I would use any inexpensive aluminum oxide belt for this step. After you have developed that comfort level with your machine, I suggest that you grind a few knives with those same inexpensive aluminum oxide belts. Once you have a feel for how many blades you can get out of those belts, it is time to try some ceramic belts. The general rule of thumb is that ceramics are expensive to buy and cheap to use due to their superior life and cut rates. A ceramic belt, for instance, may well cost several times what an aluminum oxide belt costs, but yield five or more times the belt life.

In order to achieve these results, however, you must deliver good firm controlled pressure to that belt. Ceramics love pressure. A light touch on a ceramic belt will result in premature dulling and very poor belt life. That is why it is so important to develop that comfort level with your machine before spending hard earned bucks on premium priced abrasives. Ceramics also tend to like belt speeds in the range of 5500-6000 surface feet per minute or better. That is not to say that you cannot use them successfully at lower speeds. Some makers find that they can be far more productive at lower speeds. If you can be comfortable at higher speeds, however, you will generally realize better belt life.

The major determinant of rate of stock removal is pounds per square inch of pressure at the point of contact. The more controlled pressure that you can deliver to the belt the faster the cut rate and the better the belt life. The whole purpose of serrations on a contact wheel is to reduce the area of contact and, therefore, increase the pounds per square inch of pressure at the point of contact with the same pressure from you. The biggest enemy of belt life is heat generation in the tips of the grain. The faster you remove the stock, the more heat is dissipated in the swarf which you grind off.

Okay, enough of that dribble. Let’s talk about belts. As you have found, there are a myriad of choices out there. My personal preference is 3M for a number of reasons including the fact that I have worked with them and sold their products for 40+ years and because they are the only American owned and operated abrasive belt manufacturer left. They make a quality product in the broadest range of grit sizes, backings, and minerals on the market. All of the others are foreign owned, including Norton which is owned by the French. This is not to say that there aren’t lots of quality belts made by foreign firms. Klingspor, Norton, Hermes and Sait, to name just a few of the better known brands, all make a good product. You could follow the same steps which I am suggesting with products from any one of them.

To get started, however, I would suggest that you order some inexpensive 60, 80, 120, 220, 320 and 400 grit belts to use as you develop the machine comfort level I have spoken about above. Depending upon how much stock you are trying to remove you could begin with 36 or 50 grit as long as you keep in mind that the deeper the scratch the more difficult it is to remove. Any scratch you put in at the stock removal stage, you will need to take out later. As you begin to develop the belt sequence which works best for you and yields your desired finish with the least amount of effort, you will find that you can easily skip some of these grits. In the end you will, in all likelihood, reduce the number of grits used to 3 or 4. Obviously, your object is to be able to grind and finish your blade with as few passes as possible.

As indicated above, I have a preference for 3M products such as those which you have looked at on Pops Knife Supply website. By the time you feel ready to dabble in premium priced ceramic and Trizact CF aluminum oxide belts you will have a pretty good idea of the grit sequence which seems to work best for you. At that point I suggest that you select the product types and grits from the list below which best fits the alloys you are working with and the grit sizes which best match the sequence you have established.

For use on high carbon steel in grits from 36 through 80: – 3M 963G Regal Ceramic.

Regal is a pure ceramic belt designed for use on high carbon steel. It soe not have a heat dissipating agent built into it as such a coating is not needed when grinding high carbon steel.

For stainless steel or titanium 36 – 80 grit: – 3M 967F Cubitron

This Cubitron product is aggressive and long lasting. Some makers like to use it on high carbon steel. It is, however, a bit more expensive than Regal.

For high carbon steel as well as stainless alloys in grits 120, 180 and 220:– 3M 707e Regalite Polycut. Regalite poly cut is a combination of ceramic and upgraded aluminum oxide. Like Cubitron, it has a grinding aid built into it to help dissipate heat.

For high carbon steel or stainless alloys in grits finer than 220: – 3M Trizact CF (gaiter belt) in grit sizes A65, A45 and A30. You could substitute the Trizact CF A160, A100 and A65 for the Regalite Polycut grits 120 through 220. Trizact CF is an aluminum oxide product which is coated with little rectangles each of which consists of multiple grains of abrasive. As some grit is worn away new grain is exposed. Excessive pressure on this product can cause the resins holding it together to glaze over. At that point the belt looks like it has lots of abrasive left but does not cut. To cure this, grind across the belt once or twice with the edge of a piece of steel to open up the surface again. This product is available in grits equivalent to grades 120 through 400. If you like the feel of this belt you could use it for the entire range. One advantage to using this product for the entire grit range is that all of them are the same thickness, and in fact are also about the same thickness of a 60 grit Regal or Cubitron belt.

Obviously you could do the same thing with equivalent products from other manufacturers. The important thing is that you end up establishing a sequence which works for you. Once that is established, you can test competitive products against the grits and products which you have selected. You will, at that point have enough experience to judge whether the products you test will in fact improve your finish, save you time or reduce your abrasive cost.

I apologize if I have managed to confuse you even more. In the end you will find all of the answers you need through experience, trial and error, and perseverance. Advice from others can do little more than give you some pointers to try. There is no guarantee that what works for one maker will work for you.

Enjoy!

Dan Johnson

Stephen Bader & Co Inc

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Travis,

One thing that I forgot to mention is how to remove the forge scale from your blade. Forge scale is extremely hard and will quickly dull a grinding belt. I use a side grinder to remove the scale. I have both 4" and 7" side grinders. The typical grinding disc works well, but better yet are snagging wheels. The wheels last much longer than the discs. You can get snagging wheels from MCS Industrial Supply. Get a snaging wheel to fit your side grinder and use it to remove the forge scale before going to the belt grinder with your blade.

A scale removal method I learned from Don Fogg... sodium bisulfite in water, about 1/2c. to 1c. in 2-3c. water. Not particularly noxious... it is used to adjust Ph levels in hot tubs and pools. The product I have is "Spa Down". Soaking 2-3 hours removes all scale and, nearly as I can tell, does not go on to eat the bare metal... or, at least not at a rate that causes problems.

Mike