Adjusting a stuck back

Discussion in 'Forum: Saw Identification and Discussion' started by sumo, Apr 24, 2012.

  1. sumo

    sumo Member

    Messages:
    8
    Hi there everyone, first post!

    I am/was mainly a Japanese saw user but I decided to look into Western saws to experience them too and now I am kind of addicted to back saws...

    So I got my first one in the post a couple of days ago and it needs a lot of work. The handle wood is warped and now way off center, the teeth are well formed but so dull they wouldn't cut be able to cut into butter but they are all minor issues as they can be fixed with relatively little fuss.

    My main problem is that this saw has a severe cant to it and I don't think it is original. I found a picture of another saw exactly like mine on this forum ( a Henry Rich ) and that one has way less cant. So I tried to tap the back at the toe end with an ebony block but the ebony split before the back moved. So I tried spraying a small amount of WD40 on the back/plate and got a couple of steel blocks on either side of the blade and tried tapping but again, no luck in moving the blade out of the back.

    Does anyone have any magic formula to get a saw plate out of a back? The back is steel so it could be rusted on... I'm scared of hitting the back too hard in case it bends or something.
     
  2. ray

    ray Administrator Staff Member

    Messages:
    671
    Hi Sumo,

    Welcome to the forum, you might be right, in that it could be rusted on, but here is how I've generally removed backs..

    Clamp the blade firmly between two blocks of wood in a vise, then use another block of wood to hit the back,

    [​IMG]

    Not a very good photo, but I hope you get the idea.

    If it's rusted on, then I'd just continue with the WD40, or something similar, and let it soak for a day or so.

    Regards
    Ray
     
  3. sumo

    sumo Member

    Messages:
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    Yup, I tried that and I ended up splitting the wood. I'll remove the handle and then soak it in WD40 some more and try again. I found that a hacksaw blade chopped off at the little mounting hole makes a good makeshift split nut driver!
    The handle on this saw is a mess:(
     
  4. fred0325

    fred0325 Most Valued Member

    Messages:
    1,084
    Hi,

    I have never tried this but I read it on a site about removing surface rust from a keris(kriss).

    Soak it in diesel for three weeks and what rust is going to come off, will have come off by then. Now I know that this was about surface rust but if the diesel has sufficient penetrative power, it might just work. It will not be as good as WD40, but a lot cheaper to soak the blade in, and it is less viscous than penetrating oil.

    The only other way is to heat the back to red heat, but that would be a frightening thing to do unless you knew what you were doing and were capable of smithing it staright again and re-tempering the blade if the worst happened.:(

    Hope the diesel works.

    Fred
     
  5. sumo

    sumo Member

    Messages:
    8
    Unfortunately I don't have access to small amounts of diesel. It did give me another idea though. How about electrolysis? The only thing I am worried about is the hydrogen embrittlement. Has anyone eletrolysis-ed their saw and found that it is detrimental to the teeth?
    I'll post some photos of the saw in my gallery when I get my workspace cleaned up.
     
  6. ray

    ray Administrator Staff Member

    Messages:
    671
    Hi Sumo,

    The old adage, if at first you don't succeed, use a bigger hammer... :)

    You could clamp the blade between blocks as per the normal technique, but drop the blocks down a bit and clamp two pieces of steel near the toe, so that the steel fits against the back tightly, and give it a few sharp whacks.

    I suspect that once it breaks the rust seal it will come off the rest of the way.

    Regards
    Ray
     
  7. kiwi

    kiwi Most Valued Member

    Messages:
    355
    Hi Sumo,

    I use Ray's method, and mostly it works,
    [The Wilkes Sarum saw, posted earlier this week, had an apparent 3/4 inch blade cant, but it was relatively easy to tap the spine into a position about parallel with the tooth line, and tight against the handle to eliminate the handle slop. Occasionally though, on a stubborn saw back that doesn't respond to mighty whacks, I give up out of fear of doing irreparable damage. Heat works great on nuts and bolts and solid sections, but I haven't tried it on saws for fear of affecting the blade tensioning and warping the blade]

    The spine may be locked on at one end only, so if hitting at one end of the spine doesn't move it, it is worth trying at the other end instead, to take advantage of the leverage effect.
     
  8. toolfrank

    toolfrank New Member

    Messages:
    2
    loosening saw backs

    This past winter, while trying to take out a sway in a backsaw blade, I held the saw upside down by the handle, with the teeth up, then I struck the end of the saw back upon a wooden picnic table top.

    This action resulted in the back end of the blade coming out of the backing. When I clamped the blade against the saw blade ( taking care to protect the teeth with a strip of wood), I got the blade back in quite easily, and also took out the sway in the blade.

    A kinked blade would be a different matter; but this method did manage to work well with a uniform sideways bend in the blade.
     
  9. sumo

    sumo Member

    Messages:
    8
    I managed to take a few pictures yesterday evening so I have a record of the saw in its original state. First I'm going to try removing the handle and giving the saw a good soak in WD40. Otherwise the big hammers are coming out ;)

    Just to make sure, this saw isn't really rare or historically important is it? I mean, if I mangle it a little bit I won't be cursed by the tool gods will I? I'm guessing its not so rare since Fred has another one just like it in better condition but I want to be careful.
    In any case I won't hit it too hard, I promise :D
     
  10. sumo

    sumo Member

    Messages:
    8
    OK, so a few updates. I managed to get the back off with a lot of hammering with fortunately not damage whatsoever to the back. They made that steel pretty hard! My steel block I as whacking on is seriously dented now.

    I had to drive the bolts out and I found they were pretty bent. I'm going to make a new handle and hardware I think. When I pulled the handle off a whole bunch of rust flew over my room and I found a very rusty saw plate. Its not quite eaten through the plate but it looks like its almost there.

    Anyway, I'm going to rehandle and lightly clean the plate up and make this a user. The plate is still pretty straight and I think it deserves some more use.

    I've got some pictures in my gallery if anyone is interested.
     
  11. ray

    ray Administrator Staff Member

    Messages:
    671
    Hi Sumo,

    I had a look at the pictures in your gallery, it looks like you got it off in good condition.

    Nice looking saw. Should clean up well.

    I haven't yet looked for any information on Henry Rich, other than he's not listed in the usual places... so I'd guess it's a brand used by someone, but who?

    EDIT.. I should have looked in the most obvious place... on this forum... :)

    http://www.backsaw.net/index.php?option=com_jfusion&Itemid=58&jfile=showthread.php&t=233

    Regards
    Ray
     
    Last edited: May 4, 2012
  12. sumo

    sumo Member

    Messages:
    8
    Yeah after I got the handle and back off, I've got my hopes up for this saw.

    That thread was the same thread where I found out about Henry Rich ;)
    It looks like Fred's saw is an 8 incher where mine is 10.
    His handle looks superb!

    I'll post some more pictures once I get a new handle made and mount it.