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Hand sanding final grits

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by Ian Fifelski, Jan 21, 2019.

  1. 007Airman

    007Airman

    254
    Dec 23, 2018
    I only sand in one direction. The goal is making finer and finer scratches on the metal until they are so thin you can't discern they are there. To make them blend together you need to move the metal in one direction only with long smooth strokes.
    Move down one grit if you aren't getting the scratches to blend then move up the grit for each stage, I count the strokes to keep them evenly applied. A hard foam backer helps keep flats flat and gives nice straight lines.
     
  2. Kali4nia

    Kali4nia

    100
    Aug 12, 2015
    I find going in the same direction hides scratches, I understand there are many ways. It's just never worked well for me. I always end up finding a stray scratch once I get polishing. Once you have a true 60,80,120... grit finish, it's not too hard to change the direction of the scratches to ensure you didn't miss anything.
     
  3. Brock Cutlery

    Brock Cutlery KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jan 10, 2015
    There is a big difference with any grit between a fresh piece of paper and one that has been used for just a minute or so. When it is fresh you are going to get deeper cuts that when it is slightly worn. Likely the center is going to be worn quicker than the edges too, so take care that you wear the edges of your paper down evenly with the center or you can have grief.
    Wear your paper a bit before you bear down much. Go a little light with a new piece of paper, especially toward the end of that grit session.
    I use back and forth as long as the fishhooks are shallower than the scratches I am trying to get out. It's quicker. But when you are getting to the end of the grit you are using, then one direction strokes are in order. Push or pull. Never end a grit session with a new sheet. It should be towards the end of it's bite, not fresh.
    So when you are getting to the end of the 1500 session with one sheet and you can get a decent finish, keep going with that sheet to burnish out the final finish. Switching to a new sheet now will introduce the opportunity to scuff the finish or lay down deeper scratches than you have.
    If you want to see what I am talking about, pick a section of blade and do back and forth strokes way beyond the period where you might normally change out the paper. You will see it begin to polish. This is how some makers can get a nice polish with 400 grit. On back and forth strokes you have to take care not to dig in the front or back of the sanding block you are using, especially with a fresh sheet. practice and muscle memory help there. Keep the block flat and pressure even all around.
    Get a feel for that. Then do that but in a one direction stroke. But if you have scratches in that polish then you aren't where you need to be yet. I find I don't need to pull necessarily. I get great results on a push stoke too. Just takes practice. Have to take care at the tip though. It sands more quickly due to less material.
    If you get it to a pretty good finish, but not quite there, and have to start with a new sheet then you are going to have to go with care until that sheet is worn in a tad.
    Any slight twists or deviations in your sanding path with a new sheet will give you grief. If I get a bad section like you talk about, I will take a worn sheet and do some back and forths until it's polished out. Then start carefully with a new sheet and take it through to polished.
    I use a metal bar, similar to Wheeler's and then put a piece of leather under it to finish up, especially on a convex grind. Hollows are another story of course. The leather gives it a little grace. Experiment with both sides of the leather.
    I use a light mineral oil instead of Windex or wd40, but do a lot of dry sanding also. I finish with oil always.
    Just some things to think about and experiment with. Plenty of good advice here from others too. Take it for what it's worth.
     
    Hengelo_77 and Natlek like this.
  4. Adam Buttry

    Adam Buttry

    552
    Nov 10, 2010
    @007Airman I've literally never heard, or read, another knifemaker suggest that technique for working through the grits and applying a proper hand finish. You should post a pic of one of your knives.
     
    Ian Fifelski and john april like this.
  5. 007Airman

    007Airman

    254
    Dec 23, 2018
    How is this not the norm? A belt sander only moves in one direction and a good maker takes advantage of that with multi stage grit. Are makers really sanding in random directions? That would be the worst way to develop a fine grain pattern prior to finishing.
    My teacher Harold Atterbery explained it this way, the goal is to continue to double the amount of scratches every time you increase the grit until you can't discern where a scratch existed and it is far easier to achieve if you move the lines in one direction. I don't make knives much anymore but I always follow his teachings because it worked well. Whether length or width always move metal in one direction, it's the same for any material you are trying to polish, it's not wax on wax off.
     
    Natlek likes this.
  6. Adam Buttry

    Adam Buttry

    552
    Nov 10, 2010
    The answer is obvious if you're a maker and do hand finishes. There is no way to verify that ALL of the previous grit scratches are completely removed without the following grit being applied in a bias direction to the prior. No pics of your knives eh? SMH
     
    john april and Josh Rider like this.
  7. 007Airman

    007Airman

    254
    Dec 23, 2018
    So more work for similar results that's not efficient at all. If you are putting crosshatch intersecting lines into your work because you can't see the lines getting evened out then perhaps use a magnifier, that's what I do.
    You take more time removing intersecting lines in every stage and that makes no sense. I guess it's a new world of knifemaking that contradicts what I was taught. Whatever achieves the results you want then stick with it.
    The only work I've done lately is some handle work for clients but I did a regrind and mirrored my DPx HEST F. Only sanding the length in the tip direction for both edges. 400-600-1000-1500-2000
    http://imgur.com/hPzBnEu
     
    Natlek likes this.
  8. Richard338

    Richard338 Gold Member Gold Member

    647
    May 3, 2005
    Am I seeing the right photo? Just doing a final bevel is easy for me to mirror (using my wicked edge), but I think people here are talking about large flats.
    I tried hand finishing a katana and got all set up and enthusiastic after watching the Wheeler video. He recommends switching directions. I quickly found it very slow going. Hand sanding is for the birds! I more recently hand sanded the fuller groove on my viking sword. There I was forced to stay along one direction. I counted something like 3000+ passes of various grits (on each side). Again, for the birds!
     
  9. 007Airman

    007Airman

    254
    Dec 23, 2018
    I don't have a wicked edge, just an old smiths, that is all done with a diamond stone as a backer with multi stage paper and oil, for sure each stage was about 100 strokes. I have also handmade a few swords, lots of work. Done plenty of large flats too. What I don't understand is why not just use dykem or markers to coat to see where the lines need more work, why do more work than needed? Hand sanding goes much faster if you only work in one direction. To each his own I guess I'll stick to my way.
     
  10. Maelstrom78

    Maelstrom78

    Sep 21, 2013

    I too am on the quest to eliminate hand sanding!!!

    So far here is what I have:
    -Get better on the grinder/disk :)
    -When you are at the point of hand sanding a padded/platen/disk is your friend for chasing trouble spots
    -Dang the hand sanded lengthwise scratch patters still looks the best IMO!

    I am messing around with padded platens for lengthwise grinding. But I do 90% chef knives and really their "flats" are not 100% flat and they really shouldn't be for good geometry IMO. Maybe a really soft platen and scotchbrite for lengthwise grinding.
     
  11. Richard338

    Richard338 Gold Member Gold Member

    647
    May 3, 2005
    You are probably on the right track.
    I learned the hard way that Wheeler knows what he is talking about.
    I was using some 3M finishing belts and running the piece lengthways under the contact wheel.
    It works really well, except that like Nick says, it creates subtle ripples.
    In the end, some amount of hand sanding seems to often be necessary.
     
  12. Natlek

    Natlek

    Jun 9, 2015
    All this have a lot of sense to me . . . . :thumbsup:
     
  13. 007Airman

    007Airman

    254
    Dec 23, 2018
    For sure one direction sanding works very well. This is at 2k grit and it's my daily carry so it's seen a fair amount of use since I polished it. Imagine if I went to diamond paste, next time when it needs a sharpening I will level up.
    http://imgur.com/9WjJ76B
     
  14. Spalted

    Spalted My name is Britt Askew I like making knives Knifemaker / Craftsman / Service Provider

    817
    Dec 9, 2010
    I wonder if you are talking about the same thing? :confused:
     
  15. Hengelo_77

    Hengelo_77 Basic Member Basic Member

    Mar 2, 2006
    I grind on my machine to 280 and have scratches from the spine to the edge.
    Then I hand sand ricasso to point with 240, spine to edge 400, after that ricasso to point only (600, 1000, 1500)
    Works well for me
     
    Brock Cutlery likes this.
  16. Brock Cutlery

    Brock Cutlery KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jan 10, 2015
    That is about what I do, but 300/600/1000/1200. It's nice progression.
     

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