Question on grinding belts... how many?

Justin.Mercier

Justin.Mercier

Joined
Oct 21, 2006
Messages
1,652
Ok i've searched this forum for quite a bit, i know all sorts of places from pops to trugrit to other places to buy belts for grinding... but what i havent been able to find anywhere is a good estimate of how many of which common sizes i should get to start with, so that i've got enough to do a good amount of work, but wont have to go out and order more in really short order.

What's a good number of what particular grit belts to keep on hand? Which ones will i find myself using the most often / eating up the fasest?

I placed my order and mailed my check to Norman Coote for a 10" contact wheel coote this last friday, and iv'e got a baldor single phase motor and 2 maska step pulleys comming from electricmotorsite.

Because the coote direct drives the contact wheel, iv'e got a 4-3-2 step pulley for the motor, and a 6-5-4 step pulley for the grinder side. With a 1725 rpm motor, this should give me 575, 1035 and 1725 RPM , or 1495, 2691 and 4485 FPM belt speed respectivly. I'm not sure if certain belts wear better at certain speeds or what.

If any of you with experience can let me know, what would be a good number of which belts to get, i'd appreciate it greatly.

I plan on picking up a whole mess of paint stirers to practice grinding with, since i've never had a belt grinder before, so i'm sure to make a mess of things before I get good... but practice makes close to perfect.
 
I made my first belt purchase about two weeks ago. I bought about 65 belts. Most from Pop's and a few from SuperGrit. About half were 36 and 50 grit as you will go thru the coarser grits more. I think Pop's offers a "starter set" of belts. See how that works and go from there. Good luck....
 
I only use 50 grit for heavy removal and go to 150 before hand sanding. I make about 1 to 2 knives with one of each belt depending on the size of the knife. This includes profiling the blade, grinding bevels, the guards and handles.
 
Buy a LOT:D I buy the real good 36 and 50/60 belts like Norton Blaze or Norton and Klingspor blue zirconia for rough grinding steel and the cheap Hermes 36 grit A/O belts for roughing out wood. I still use Norton zirconia 100's and 120's for some finer grinding, but I have gotten really hooked on the 120 and 220 Klingspor gold stearate treated A/0 belts for fine grinding of blades. They bump a bit because the backing is so thin and flexible but they are great for doing plunge cuts. I still use the 100-120 Norton zirconias to grind heat treated blades down to a thin edge and then finish with 120 and 220 Klingspors. i have been very unimpressed with the "structured abrasives" type belts like Gator, Trizact and Micron and I don't think that most of the ceramic belts are worth the extra money over the zirconias. If you went with the Klingspor zirconia and sterate A/O belts in the grits that Mace recommends, you would have all that you need. Just remember that they are pricey and you don't need great large grit belts for wood.
 
I'd get about three each of the coarser belts in about 36, 60, 80, 120 grits. I really love using 120 grit, it seems to be the all purpose belt for me except hogging and finishing.

You'll go through your finer grits (i.e. 220, 400, 800, 65x, 30x, 5x) at a much slower pace. I'd get two each at most to start.

From this assortment, you'll get a feel of what you'll use more of and then place another order at that time.

BTW, why practice on paint sticks? I know the reasoning, but you might as well get some blade steel and practice on it. That way, you'll be sure to try your best to produce a working blade in the end. There's nothing like practicing on the real thing to get a feel for it. In the end you may end up with a good blade that can be used, rather than a useless piece of wood. With this method, I scrapped my first two blades but learned alot in the process. I'm still a newbie, but have since completed 8 blades without scrappage. The hands-on learning that I received from those two scrapped blades was worth many times more than the $18 of wasted ATS-34.

I suggest you go right to grinding on some good blade steel.

Good luck,

Mike L.
 
logem said:
I'd get about three each of the coarser belts in about 36, 60, 80, 120 grits. I really love using 120 grit, it seems to be the all purpose belt for me except hogging and finishing.

You'll go through your finer grits (i.e. 220, 400, 800, 65x, 30x, 5x) at a much slower pace. I'd get two each at most to start.

From this assortment, you'll get a feel of what you'll use more of and then place another order at that time.

BTW, why practice on paint sticks? I know the reasoning, but you might as well get some blade steel and practice on it. That way, you'll be sure to try your best to produce a working blade in the end. There's nothing like practicing on the real thing to get a feel for it. In the end you may end up with a good blade that can be used, rather than a useless piece of wood. With this method, I scrapped my first two blades but learned alot in the process. I'm still a newbie, but have since completed 8 blades without scrappage. The hands-on learning that I received from those two scrapped blades was worth many times more than the $18 of wasted ATS-34.

I suggest you go right to grinding on some good blade steel.
Good luck,

Mike L.
Click to expand...

i foun that you can even do some hogging on smaller blades with 100 grit zirconia belts. If you go with the Blaze belts, you can use 60's. The hog very well and they don't throw grit at you like 36's can. The bad news is they are very expensive.
 
The reason i was going to practice with some wooden 'blanks' first... was because then i wouldnt be wearing out belts before i get more practice. I've got a decent stock of 1084 (about 30 feet of 1'x1/4) but all the other stock i have is O1 round stock that i need to forge to shape. Paint stirers would give me something quick to just get the feel of things with without chewing up a bunch of belts in the mean time =)
 
Yes, better to use less grits and better quality belts. Also, trying to take things too far on a grinder can cost you way more time, money, and tears than simply taking the time to hand finish.

John
 
I've found in my limited experience that coarser grits wear out much faster than finer grits. How faster I don't know. Maybe twice as fast. Or perhaps is just because one uses them more.
Anyway, purchase more coarse grit than fine grit.
I use 40, 80, 200, 400 and 600. I have also 800, 1000 and even 2000 grit belts, but in my opinion past 600 is not worth the time on carbon steel, and a 600 grit lengthwise satin finish (by hand) looks much better than a 2000 finish, especially if you have a differential quench.
On stainless, especially powder steels, you may go for a mirror surface, but again a good hand finish beats the grinder. In that case you may perhaps go for 800 grit cork belt before hand finishing.
A lot of people use a cloth wheel or felt wheel with tripoli and get marvellous results, but I've heard too many horror stories about the polisher, and much prefer hand polishing.
 
Justin: I would recommend not going coarser than 50 grit to start. I use 60 grit myself. I find they last longer than 50's

From 60, go to either 120 or 180 grit. I go to 180.

From 180, go to 220, then HT. After HT, you can regrind with a 220 grit belt, then finish as you desire.

I recommend either scotch brite belting or buffing with one of the 220 or 240 grit compounds that come in the plastic tubes. If you use a 1/3 HP, 1750 RPM motor and an 8" wheel, you'll get a nice finish and be able to use the buffer safely.

So, my recommendation is 20 of the 60 grit, 20 of the 180 grit and 20 of the 220 or 240 grit. See how this ratio plays out for you, and adjust your second order accordingly.

Once you become proficient at grinding, you can start using finer belts and working on your finish. I would rather see a nice, crisp 220 grit finish than a poor 600 grit finish. Keep it simple at first until you have mastered the technique.
 
rj martin said:
Once you become proficient at grinding, you can start using finer belts and working on your finish. I would rather see a nice, crisp 220 grit finish than a poor 600 grit finish. Keep it simple at first until you have mastered the technique.
Click to expand...

Those have got to be some of the wisest words ever spoken regarding grinding! I killed myself on the first several blades trying to bring them up into micron belt territory, only to waste it because I didn't know what I was doing.

...well, I still don't know what I'm doing, but you know what I mean!
 
I'm just starting out but one word of advice I was given that is proving true is to start slowly. By that start with a bit finer grain belt than you normally would. This keeps you from making an irreparable mistake from grinding too aggressively. You can't put metal back on.

Charles
 
Thanks for all the advice so far. I'll go with some 60 120 and 220 belts for now, and get some 36s or so when i'm more comfortable hogging material without screwing up. Now for a follow up question. There are a ton of different types of belts out there, which should would you reccomend?

Blue zirconia belts for hogging at the lowest grits, then ceramic 3M belts at 120 and 220?

Should I be picking up some of those yellow Klingspor belts for grinding plunge lines over the edge of my contact wheel? Are the 3M belts fleible enough to do that on their own?
 
I start with 60 grit ceramic belts. I try to take my flats up to 400 grit before heat treating. I don't like to have to do much work on the flats after I'm done with the main grind. So I usually go 60, 120, 220, and 400. After I fininsh the flats I'll start my grind. I do 60, 120 and 220 before heat treat. After heat treat I grind the flats with 400 again then 600 and I'm done. Sometimes I'll leave it at 400. Some times I hand sand it to 600, but it depends and how the blade is looking or if I'm afraid using the platen will start affecting my grind lines. Then, I grind the blade using a 400 and then 600. If I'm going to polish the blade I always go to 600. If I'm going for a satin finish I stop at 400. If I am "attempting" a hand finish I stop at 600.
 
I just placed my first order w/ Klingspore a couple of months ago....NICE products and customer service!
I talked the salesman into sending me a couple of sample belts...
The one that stood out the most was a "RED" ceramic belt in 36 grit.
These things just keep on cutting. I taught 2 of my nephews and 1 of thier friends to forge blades...we ground 4 blades using the one belt....heat treated....used the same belt on all 4 knives for the clean up. I've used it to grind a couple of more blades and just the other day profiled 6 more blades with it. I just tossed it out.
Great belt...in my book. Expensive...but worth it!
Mace
 
I use 50 grit belts 120, 320, 400,800,1200,2000 and I hand rub starting with 120,180,320,400,500,600,800,1000, and then it starts to come into it. I like using Norton, 3M belts. I get good miles out them.
 
Thanks for all the help everyone. I just placed an order for some belts from Pops. getting 15 60grit zirconia belts, 10 120grit 3M ceramic and 10 220 grit 3M ceramic belts for now. My budget after ordering the coote, motor, pulleys and other stuff this last week is down to almost nothing, so I got as many belts as I could for under $150
 
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