Saw making advice needed

Discussion in 'Saw Makers Forum' started by Matthew, Nov 18, 2020.

  1. Matthew

    Matthew Member

    Messages:
    5
    Hello,

    I have bought a few things to make a few saws. I have a retoother with bars up to 16ppi, I have some. 020 spring steel. 6 inch by 25 inches. Plenty of of old/recycled saw screws from old saws.

    But I need to buy or make some backs. I do not have a mill but I do have a drill press. I cannot access the link where someone used a drill press to slot backs. Did that work?

    I searched and found that Blackburn Tools sells backs. I reached out and I will see what he says. TGIAG and Florip Toolworks sell backs but not currently.



    What should I look for in a saw back? Thickness? Height? Slot depth? And are these pressed on at all? Or do I need a .020 slot for a .020 blade and glue it?

    Personally I'm ok with either folded or slotted. But I know I cannot get any from TGIAG or Florip Toolworks at the moment.



    Matthew
     
    Last edited: Nov 18, 2020
  2. Dusty Shed Dweller

    Dusty Shed Dweller Most Valued Member

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    121
    Matthew, you're starting to paddle in murky waters here and risk opening up the old "slotted" versus "folded" backs argument. Those doing it will certainly not give you the 'how to' as this IP is typically closely guarded proprietary information.

    I'll state my bias up front, I'm very much in the folded backs camp.

    The bottom line..... Folding backs is very difficult to do well, and we don't know how the old Sheffield companies managed to do it so effectively. It's not as simple as squishing bar in a press. The benefit of folded backs is repairability - the ability to re-tension the plate as it can move relative to the back if there is a problem such as a catch etc. Folding requires tooling that costs thousands of dollars and a big press, plus knowledge of working brass. It's not a backyard operation.

    The slotted back school is a purely modern development. Basically you mill a slot into brass/steel bar and glue the plate in. Only nominal clearance is required and you don't crimp it later. Technically it's an easier operation because a competent mill operator should be able to this basic work on a standard mill, but in reality accurate slotting is difficult over significant lengths. Any wobbles will transfer directly into the plate. The main issue with a glued back is that the plate is fixed, so any issues in use will irreparably kink the plate. Another problem I have is that many of the slotted backs aren't solidenough, and any movement will mess up your dovetails.
     
  3. pedder

    pedder Active Member

    Messages:
    38
    We use slottet spines. for a 0,5mm Sawblade i wloud use a 6mm strong and 15-25mm wide Spine. Question of taste if you like heavier saws better or lighter.

    To saw the spines you need a circular saw blade lik this

    https://www.ebay.de/itm/201681556204

    and a holder for the sawblade:

    http://woodworking.de/webbbs/media/leise/83/83090_11.jpg

    I don't have tat kind of holder at any distributor . You might want to make your own.

    Here is a report of some german makinghis first saw. I think it is well made!
     
  4. Matthew

    Matthew Member

    Messages:
    5
    For the time being I'm using slotted backs from Blackburn tools. I wanted folded as well so I could use both and decide what I prefer. Unfortunately only slotted are available right now because Florip Toolworks and TGIAG are not currently selling any. Unless you guys know of another source?
     
  5. TraditionalToolworks

    TraditionalToolworks Most Valued Member

    Messages:
    181
    I'll offer you some advice, and to answer the question as to if the drill press method worked, yes, Ray has slotted backs on a drill press as I recall. This is Ray's site.

    If you want to make saws you need to solve the problem of making backs. Dusty offered you pretty sage advice, it's not easy to fold backs and not easy to slot them in most regards either. However with a bit of persistence you can make pretty good backs that will server you well.

    If you really want to make saws you will need to solve the problem. Either way you will need to learn about and understand metalworking as the problems you'll need to solve are metalworking related, not woodworking. Getting a mill is a valuable tool, you can do many things with them, as-is a lathe, they come in handy to turn your own screws and nuts.

    There are 3 important pieces to making a saw, the saw plate itself (i.e., stamping/cutting the teeth), the back (whether slotted or folded), and the screws/nuts to attach the blade/back to a handle. Some people find places to buy these components, some make their own, and some buy some and make some of their own.

    One way you didn't mention is the laminated method of laminating the plate between two pieces of the back and either using epoxy and/or adding pins that are peen'd together. There was a guy named Vlad that used that method some years ago.

    Either way if you really want to make saws you will need to learn to do this yourself. You will need a pretty hefty brake in order to fold brass thick enough, so that's a deterrent, and for slotting it's not so much that a mill is so expensive, it's the knowledge to be able to precisely slot the backs and assemble it all. As with everything most people get better with time...

    I'll state my bias also, I'm in the slotted camp.

    Oh, quite contraire, I think it's safe to say they used brakes. In days of lore they didn't have the ability to easily slot a back, and the slotted back is something that came out when Independence Tool which Lie-Nielsen bought came up with the idea. It was actually Pete Taran who came up with the idea.

    I don't think saws need to be as precise as you make them out to be, it's a tool after all, you get used to the tool you use.

    The reason I'm in the slotted camp is that I don't buy into the whole "tension" concept, as metal doesn't need to be in "tension", or even hold tension unless force is applied to it. it just needs to be straight in order to work correctly.

    There are 2 things for certain with a folded back.

    1) it has the advantage that You will be able to readjust the saw plate at a later date without heating the back/plate up to separate, since the back can be removed fairly easily.

    And

    2) You will almost certainly need to readjust a folded back as when they drop it distorts the blade and back, and this is why I don't care for folded backs. Very rare you will find a vintage saw that doesn't need to be readjusted.

    I will also add that you don't need to spend massive amounts of money in order to either fold or mill slots in brass. Mike Wenzloff did it for years using a cheap mini-mill, and his jig was made out of wood to hold the brass backs when he slotted them.

    Leif Hanson built his own brake to fold backs, years ago, here's a good document to read: http://www.norsewoodsmith.com/files/image/backsaws/pdf/Backsaw_Project.pdf

    If there is a will, there's a way. But it will take some ingenuity and persistence however you do it.
     
  6. Charlie Earnest

    Charlie Earnest Member

    Messages:
    6
    Matthew,
    Blackburn has a blog section where Isaac lays out the process for making a saw start to finish. The depth in his backs are 5/16”, I believe, except on the 9” saw. I slot backs using a drill press, not even a nice one, and slitting saw blades I bought for a dollar from an antiques place. I don’t use epoxy. I prefer a friction fit like the one described in the Blackburn blog. Although this does come with its own trial and error process. McMaster- Carr is where I buy my materials. Brass bar for backs, spring steel, and you can also buy a slitting saw and slitting saw arbor from them as well. Good luck.
     
  7. Matthew

    Matthew Member

    Messages:
    5
    I am working on the important pieces now.

    First I have plates cut and a retoother and retoothing bars up to 16.

    The screws I am having to buy.

    The backs... I have purchased materials to press them in my press. Ill keep you guys posted.


    Blackburn walkthrough is where I started. I still have some of his milled backs too. I havent tried to make my own slitting jig yet though. Starting with the folded backs project.
     
  8. Matthew

    Matthew Member

    Messages:
    5
    Success!

    I made some new toys for my press. I finally got the proper die and punch setup welded together. Made my own lower die. Perfectly folded brass. .093 thick, 11 inches long. Just a test piece but very happy. No bows, twists, or cracks.
     
  9. Charlie Earnest

    Charlie Earnest Member

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    6
    nice job. I think I’ve already told you this elsewhere though....
     
  10. Batman3000

    Batman3000 New Member

    Messages:
    4
    I've recycled a folded back from a rusted out trash market saw.