Recommendation? Is 36 grit worth it?

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Alex T., Dec 2, 2019.

  1. Alex T.

    Alex T. Beginner knifemaker Knifemaker / Craftsman / Service Provider Basic Member

    86
    Mar 10, 2019
    Hi all,

    I had luck finding myself a local supplier (the store is litterally 10 minutes from my home, add to that free shipping and a discount for large quantities) of SIA abrasive belt in ceramic (2511 siabite). Now, I have never used 36 grit belts are they worth the extra price compare to a 50 grit? (The 36 grit are 3$ more than the 50 grit per bel, and thats with a discount since I will be partner with my store), I never found the need to go smaller than 50 grit, but if you tell me that a 36 grit will outlast a 50 grit then let be it. I would only use the 36 for profiling blades and bolsters, not for bevel. Would it be worth it?
     
  2. scsep178

    scsep178

    4
    Oct 21, 2019
    In my limited experience, if I didn't use 36 or 40 grit belts, I would be grinding forever on my 1X30. It already takes longer than I would like, so I can only imagine the same would apply for a 2x72. I only use them for profiling like you said, but I find them a welcome option in my shop.
     
  3. Alex T.

    Alex T. Beginner knifemaker Knifemaker / Craftsman / Service Provider Basic Member

    86
    Mar 10, 2019
    I didn't state it but yes Iam using a 2x72 grinder, drirect drive, 2hp with vfd.
    And for the belt life? From your opinion, does 36 grit outlast a 50 grit belt enough on profiling to justify 3$ more? I might also just use them for my 304 ss bolsters. I'm really ambiguous about it, that's why I am asking here :)
    Thanks for your input!
     
  4. scsep178

    scsep178

    4
    Oct 21, 2019
    I suspect that my belt life will not coincide with the life on a 2x72, but for reference I can grind out the profile on a handful of small EDC type knives per belt before it starts to under perform. With a 60 grit belt (the next size up I have) it wouldn't last that long. I would say they are worth a shot.
     
    GABaus likes this.
  5. E.Carlson

    E.Carlson KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    738
    Mar 28, 2016
    I feel like they strip out faster when you are profiling with them, If you use 50 grit to grind your bevels, I'd just use the worn ones to profile with.
     
  6. Sam Dean

    Sam Dean Gold Member Gold Member

    Aug 3, 2012
    I agree with Erik. I now use 36 grit AO/Zirc belts to rough shape handles, but that's it. 50 grit VSM ceramic on rough bevels and profiling.
     
    buckfynn likes this.
  7. Tom Lewis

    Tom Lewis

    Feb 24, 2000
    I get lots of use out of 36 grit. First I use them to taper tangs. Then when they start to lose their cut on the tangs I use them to grind bevels. When they start to lose their cut on bevels I use them to profile blades. I like the Norton 980's. I also run a fast speed and use a lot of pressure. That breaks the ceramic grit up and keeps a sharp belt.
    I might say before I grind bevels I use a dull belt to grind a 45 degree angle on the edge. That way the grit doesn't get stripped out.
     
  8. Alex T.

    Alex T. Beginner knifemaker Knifemaker / Craftsman / Service Provider Basic Member

    86
    Mar 10, 2019
    Thank you mr Carlson and Dean. I am also using 36 AO on handle, it is very fast.

    Mr Lewis, do you think a 36 grit would outlast a 50 grit for the same task? Time is not a problem for me, but the belt life is. I don't have a lot of cash and I don't want to shell out a lot of money on a 36 grit if a 50 grit last as long. With one 50 grit (merit ceramic), I estimate I can profil and taper about 5 knife (about 11" each, 5/32 thick and 440c). I start my bevel like you, break the sharp edge than switch to a new belt. Can you grind and taper more knife with a 36 grit?
    Anyway thank you guys, I will probably just order the minimum quantity for 36 grit and see by myself if the price is worth!
     
  9. Natlek

    Natlek

    Jun 9, 2015
    It is not wise to use NEW coarse belt on small surface of steel , they will wear fast ..........
     
    GABaus likes this.
  10. Alex T.

    Alex T. Beginner knifemaker Knifemaker / Craftsman / Service Provider Basic Member

    86
    Mar 10, 2019
    So they would basically be useless? Since I would only use them for this?
     
  11. Natlek

    Natlek

    Jun 9, 2015
    5/32 thick is around 4 mm , right ? So with 36, 40 grit ceramic you will have small amount of grit in contact with steel , so they will break down FAST exposing fresh sharp edges .............
     
  12. Natlek

    Natlek

    Jun 9, 2015
    This is recipe for long life of ceramic belts
     
    Last edited: Dec 2, 2019
  13. Natlek

    Natlek

    Jun 9, 2015
    Take coarse file and try to use it on spine of thin piece of steel , then take fine file and see difference ;)
     
    GABaus likes this.
  14. Tom Lewis

    Tom Lewis

    Feb 24, 2000
    The way I grind, 36 is way faster and lasts me a lot longer than a 50 grit belt.
     
    GABaus and Storm W like this.
  15. Natlek

    Natlek

    Jun 9, 2015
    You use them in smart way , Tom :)
     
  16. Sam Dean

    Sam Dean Gold Member Gold Member

    Aug 3, 2012
    @Looney36 - You should really get a few and find out for yourself. I think with any craft, a lot comes down to individual style and personal preference. You might find the 36 grit belts are everything you wished for - or they might not work at all with your setup. We all do things a little bit differently, and the best belt life for me may be radically different than what works best for you. However, if you don't try for yourself, you'll never really know for sure.

    One thing that helps me extend life the lower grit ceramic belts (and structured abrasives too) is dressing them with a diamond grinding wheel dresser when they glaze over. The dresser fractures the abrasive particles and keeps it free cutting a little while longer. I usually do this when grinding hardened blades, when I want to keep heat down but still cut metal. When grinding pre-heat treat, I just use more pressure & hog metal away.
     
  17. razor-edge-knives

    razor-edge-knives Moderator Moderator Knifemaker / Craftsman / Service Provider

    Apr 3, 2011
    I'm with Tom on this,they are good stuff. Check out the economy line at pops knife supply. I can get 3 grinds out of each belt on hardened m390 folder blades, fill full flat ground
     
  18. Alex T.

    Alex T. Beginner knifemaker Knifemaker / Craftsman / Service Provider Basic Member

    86
    Mar 10, 2019
    I just had a talk a few minutes ago with a technician in abrasive from SIA, and I probably learned more things about abrasives than by reading on the net for a year. A few things, while not fully related with the subject (but I think you guys will find this interesting) the tech mentionned:

    - Ceramic belts are priced with how much % they have of ceramic (more ceramic = higher price). With the stats I was given, it was clear that the nortons, vsm and klingspor were not cheaper after all if you take into account the % of ceramic they got vs their price. Only the 3M were comparable in price to the SIA for the amount of ceramic.

    - Depending on the situations, zirconia belts will outperform both in cut and durability a ceramic belt on simple carbon steel (mostly depends on the way the steel approches the belt). In fact, ceramic belts are not suited for mild steel, or even annealed high carbon steel.

    - Unlike popular believe, ceramic belts don't need a high pressure to work properly. In fact, too much pressure will clogg the belt, make the piece hotter and make your belt not last long. The tech told me: the abrasive is here to help you grind the steel, if you have to put all your body on the piece it means the grit or the belt you have is not suited for this steel, switch to a different belt or go to a more aggressive belt.

    - Using anti clogg (the tech suggested using simple a bar of soap) will significantly help avoid clogging and facilitate the grain to break

    - Silicon carbide sandpaper will cost you more and have a shorter life but will give the best finish

    - AO sandpaper will cost less and have a longer life but it might take longer to achieve the same finish

    - With heat, AO "fuses" with the chromium oxyde in stainless steel (a chemical reaction), making it useless for this application (now think about what I said before about the amount of ceramic in a belt)

    - A 70 duro rubber wheel is to soft to get the most out of a ceramic belt, 80 duro and up would be ideal. It is better to use the flat platten if you have a softer contact wheel to ease the breaking of the ceramic grain.

    Now, theses infos are not from me, they are from someone whose only job is to recommend industries wich abrasive is best suited for the job, the tech even told me to try the other brands and see by myself, she seemed really confident that her product outperform Norton and VSM, she told me only 3M was a challenge. Now you do what you want with this information, I just tought this information could be useful. But in the end, the tech told me the same as you @Sam Dean , I have to try for myself, I am the one in front of the grinder so by trying I will know what suits the best for me. Base on this information, I will go with the 36 grit. I will also keep you updated on the Norton vs SIA vs Merit (have some left), turns out I ordered some Norton R999B in 36 grit, I will compare it to the 2511 from SIA (they apparently have an even more concentrated ceramic belt, the 2515, but the tech told me it might be too much for my application)
     
  19. razor-edge-knives

    razor-edge-knives Moderator Moderator Knifemaker / Craftsman / Service Provider

    Apr 3, 2011
    that is some interesting info. I don't think I have ever even heard of SIA until this thread
     
    GABaus likes this.
  20. Hengelo_77

    Hengelo_77 Basic Member Basic Member

    Mar 2, 2006
    Just on the side, in shoe making we use 24grit belts on leather and rubber. Works very good on hard wood as well
     
    Willie71 likes this.

Share This Page