How many belts to buy?

J

J. MacDonald

Joined
Jun 8, 2000
Messages
3,140
OK, so my KMG is incoming (yeah!) and I need to order some belts as I'm sure the 2x42s I have laying around aren't up to the new machine. So I have to order in a bunch of 2x72 belts asap.

I'll have a variable speed set up so I can slow them down a bit.

From the research I've done (yes, I can use the search function) it looks like the Norax or Trizact belts would work for the 50/60 grit and 120 grit belts, and then the nod seems to go to Klingspor for 220 and 400 grits.

My question really comes down to how many of each grit to order? What is the ratio of coarse grits to finer grits that I can expect to use? So far I've only used A/O belts on my Craftsman, so this is a whole new arena for me. I expect to be grinding 154CM, S30V and 6/4 Ti along with various handle materials. While I'm a hobby maker, I don't want to have to re-order in sixty days, so how many overall should I order?

Any more recent recommendations regarding the various compositions would be welcome if there have been new developments regarding the various abrasives, but mostly I'm looking for recs on overall quantities and ratios of coarse to fine.

TIA.
 
If you can afford it, I would say get 10 each of 60 and 120 and 5 each of each successive grit you desire, up to 320 or so....and the more expensive belts are absolutely the way to go. My two peso's
 
I usually order 50-70 belts at a time, the grits I order depend on what I've used up since the last order.
 
Here's the ratio as I use them, based on what I've thrown away in the last six months, 36 grit being 1:

36 - 1
60 - 2
220 - 10
320 - 6
400 - 16
600 - 7
800 - 5

The best advice I've ever heard about belts is "use them like they're free." It's so true, and so hard to live by. ;)

I use the 320s mostly for handles and the 400 and beyond for metal. In the heavier grits I use ceramic, mostly 3M 967 or 977. I'm not sure of the brand of the 220 ceramic, but the backing of the ones I have is too stiff for doing contours on handles; I'm looking for a second 220 for that purpose, and probably it'll be A/O. The 320 is A/O and the 400 and up are Norax. I use the 600 and 800 pretty much only when I'm mirror polishing a blade, otherwise I go from 400 to either hand rubbing (starting at 220) or Scotchbrite Ultrafine for those hard working inexpensive knives.

The thing I like about Norax is that you can refresh the grit surface by scraping it with the burr of a steel cutoff or other sharp edge. That makes the belts last significantly longer and they become far cheaper to use than anything I've tried before. I haven't been able to do that with Trizac.

Ceramic belts work best with heavy pressure, which helps to fracture the surface and keep it cutting.

I get them all from Tru Grit though I believe Pop's has them too. One more thing to consider is sheet abrasives; someone recommended here a while back to get sheets from all the same manufacturer, and that is good advice. That way the grits maintain the same relationship, which I've found is not dependable between manufacturers. I've been using Klingspor from Tru Grit and it's good stuff. They have decent prices on 50-sheet packs, something like $35. I use 220, 400, 600 and 1500, more of the 220 than anything.

I'm sure you know this since you ordered variable speed, but faster for the heavier grits and slower the finer the grit. Perhaps more importantly, variable speed greatly enhanced my learning curve, and I couldn't live without it anymore.

Good luck and have fun! I know how psyched you are, and you're going to be living in heaven for a while when you get that bad boy running. :D

Edited to add: Should have read your question more closely. I try to order belts once a year, and usually order about 30 220s and 40 400s. This is the first time I had the sense to keep track of what I've thrown away rather than try to figure out what I'd ordered the previous year vs what I had left over. Live and learn. I'll have a better fix on this ratio in a couple of years. Anyway, I usually end up spending about $500 when I order belts.
 
I concur with Dave. I bought three 36 grit belts on my original belt order in March and I still am using one of them. Same with 60 grit, but the higher grits wear out a lot faster. Things I've learned:

1) For titanium, buy some of the Cubitron ceramic belts from 3M. I think I got a 60 grit belt (they're about $5 a pop) and it cuts titanium like you wouldn't believe. The same people who turned me on to these also said to run the belts as slow as possible, and I use very little pressure, too (fewer sparks = better, I guess) and it worked fanstastic. Pop has these, as well as other places.

2) For the higher grit belts, run slower speeds. I use pulleys on my grinder, and I run at the highest speed up until 120 grit, then I switch to my slowest speed and it seems to work good.

3) I like the aluminum oxide Klingspors in 220-400 because they are so flexibly and they come in on the plunge grind nicely. They seem to wear out very quickly, though.

4) It's true that the gator belts have no discernible "bump" on the platen. I have an A30, I think, that is about 600 grit and it's smooth. Hope it lasts a while, though! :eek:
 
"as if they were free" . I'll add that I've found the simple belts by Klingspor and Hermes are by far the best, and when they even hint at cutting a little less, just pitch their three dollar ass out the door. You will find that there are very good uses for the more rigid belts as well as the "J" flex stuff and then it's to hand sanding.........


m
 
Yep. When I first talked with Pop he was selling me up on the really high grit stuff, but I had this notion that I was still going to be doing lots of hand sanding. Even when I go up to 600 grit on a flat grind I go back to 220 grit wet-dry and hand sand 200, 320, 400, 600, 800, 1000, 1500. And even then I have a scratch or two still winking at me from the belts! Little bastids! I'll get you! ;)
 
If I'm going to be doing hand sanding I take it to 400 on the machine and back to 220 to start the hand rub. But if you angle the blade against the platen or wheel a bit, even 30 degrees or so, you can see the scratches left behind from the previous grit and get them out. Took me a while to convince myself that was true, but it is.
 
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