Newbie belt question

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unky_gumbi

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Aug 28, 2009
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So I started collecting the parts to build my grinder, well I got the motor so far and will be ordering some other parts next week. It will be a long build and I am in no rush because I wont be able to use it till the new year any how.

Something that has come to mind though is belt selection, not what brand but what grits. For the little 1X30 I was using on the last coupe of knives I would start out with a 80 grit AO belt and finish up with a 120 AO before going to a file to square things up and then hand sanding to 400 before HT.

With a proper grinder (2X72) what would be the best range of grits to buy? From my reading here it almost seems that people are getting a better finish at a lower grit then I am able to with the cheap grinder. Do real grinders give a better finish with experience, and will I notice the difference right away? The reason I am asking this is that I will probably order a few belts way before the build is complete just so I have them there to help with the alignment of the wheels and so I have something to run on it when its finished and not have to wait for them to come in after.

It also seems that a lot of makers swear by Norton Blaze belts so I think that may be where I go till I figure out what is best for me.

So many belts and I have so little knowledge in that area:o
 
The more I grind the better I get. I think you will notice the difference right away. 2" wide belts give you more surface to remove metal, plus a much wider area to align your steel to so you will get less dips and be less apt to misalign and screw something up. I start out with 50 grit to finish off my profile from the saw if from flat stock and then rough in my bevels. Same with a forged blade to knock down the hammer marks ( I am no Richards) then I go to 120 and 240. I use the 3M ceramic belts in these grits. Partly because they work great and I got a great deal on lots of 50 when I had some money. When they are gone I am going to try the Blaze. Then I go to the Norax belts. These are great belts. Very flexible and work for a quite a while. I now start at the A65, but, may drop the 240 step and start with these at A100(220 grit). Because they flex well I can run them over the edge of the platen or wheel and clean up and adjust my plunges. After the A65 (400 grit)then I go the A45(650 grit). I have been going to the disk and using Tracy's Norax in 30,16 and 5 from there on flat grinds. But, as I get better on the 2x72 I am thinking I will get some 16 and 5 in the belts. I love the disk, but, he belts are faster and last longer. I have a VFD and slow the machine down as I go up in grits. The slower I go and the finer grit I use the more control I get. Part of it is as I get better I get more confident and don't worry about screwing up a flat on the belts. Besides hand sanding it is the only way on the hollow grinds and I am doing that more now. I love my 2x72s. I have a KMG and a homemade clone. The clone I mostly leave the small wheel attachment on. I use a switch to change the VFD from one machine to the other.

I have some cheaper AO belts in 36, 80 and 120 that I use to rough in my wood before I go to hand sanding. On scales after I use these to get even to the tang on the edges I go back to the good belts to take the scratches out of the tang edges. When I do this I use the rubber belt cleaner a lot as the wood will clog up belts quick, but it doesn't take long to clean up the scratches on the edges and I keep the piece moving back and forth across the belt so as not to wear or clog one spot.

This is just my way and I am sure others have theirs. If we were all the same it would be pretty boring.
 
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Get a glass or ceramic platen face, I think in a lot of cases that is the real difference. That or just a stronger steel face than the cheaper grinders have. I just got the sears 2x42 and put a glass face on it from USAKnifemaker, big improvement.

Also, just passing on what I've learned here, the 3M Trizact belts are great. Make sure you write down what code = what grit, because it can be confusing and doing it by feel isn't easy like on traditional belts. They're only a little more money but so much better than the standard belts. I haven't done any bevels with mine yet, or any major profiling, hopefully today, but fooling around just to try it out showed that it's a huge improvement over no glass and standard belts.

My routine for steel (not just a knife thing) is major shaping on 36 grit then 60 or 80 to get closer to the final line. Then 120 to the outside of the line, maybe just a bit extra left. Then 220 to finish. If we're talking something that needs a real nice finish I keep going right on through 600 with belts. I actually start a lot finer on wood, you can tear through it way too fast for my taste on one of these machines.

Check out true-grit.com
 
Remyrw said:
Get a glass or ceramic platen face, I think in a lot of cases that is the real difference.
Click to expand...

It sure does help!

I'm going to a little against the typical grain here... I learned this from a post Ed Caffrey wrote, he mentioned who told him but I forget...

Try getting as close to finished shape as you can with your 50, then skip straight to 400 to clean up the scratches. It seems like it's going to take forever at first, but actually saves a lot of time in the long run.

I've been doing this for a few weeks now and I'm convinced that going through every grit in-between is a waste of time and money. Once you get up to a nice 400 or 600 on the belt, then hand-sand as normal. The finer grits naturally don't take so long and I don't know for sure yet if skipping right up 1500 or 2000 will save time or not.

If you're stepping up to better belts, you'll likely want to step up to better paper too, if you handsand. I've been using regular 3M s/c paper up to 1000 grit; there may be better options for those grits. I just started using Norton Black Ice paper in 1500 and 2000 and it's good stuff. Very consistent, cuts quickly and lasts well. It seems pricy at $1.00 a sheet, but I just finished two 4" blades with half a sheet of each grit. 50 cents a blade, baby, I can live with that.
 
Wow 50 -400 I can only dream, Grits 40 - 120 should track about the same since they have a very similar backing, 220-320 are usually similar and 400+ are kind of a floppy belt. I think a belt in each range will be needed to set up since they are on differnet backings and may track a bit different. The finer belts are the most difficult since they are really thin and flexible.
 
Unky, I've tried the Blaze belts, and I'm not sure they are that much better than the zirc belts. I don't have alot of grinding experience, but they don't seem to last much longer than the zirc's. Maybe they do run abit cooler ? Considering that you can get two zircs for the cost of one blaze ... just my .02
Shant
 
The main reason I am moving over to a 2X72 is to save some wear and tear on my elbows so the less hand sanding I have to do the better.

Now for the next grinder question, on average how many knives does a belt make? I know that some materials will wear them faster and that sometimes belts just let go even when new. With my little 1X30 I get maybe 2 knives and its time to get a new belt, and that is pushing them to the end of their usable life for a knife. I treat belts and sandpaper like they are free while I am using them, but the purchase price for them is still in my materials list. I haven't made that many knives, only completed 5 and now have 6 in various stages of completion, but after the first one I decided to keep track of my time and materials on each knife.

In the new year my goal is to have my new hobby pay for an EvenHeat 120V 18" Heat Treat Kiln with Rampmaster III controller. Its a long shot, but we have to have goals to improve:p In truth what will most likely happen is I will work a crap load of OT next year and buy it that way. As much as I like the HT service I am using I would like to be able to take a piece of steel to a finished knife completely on my own.
 
Blaze belts are that much better than the zirc belts, especially in rougher grits.

I use 40/80/120 blaze a lot. norton blue zirc in 80, 120, 220.

I've tried norax belts, and I like the thickness and stiffness and all, but I can't seem to get them to work for me. I can go all the way down to a45, cleaning, working slow, and I'm STILL having to run back to 220 to start my hand rub. I need to get a few more and see what i'm doing wrong. If I could start hand rub at 400 or even 600 on the full convex blades, I'd be stoked beyond belief.
 
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