Spear & Jackson 12" Backsaw

Discussion in 'Forum: Saw Identification and Discussion' started by TKW, Dec 15, 2014.

  1. TKW

    TKW Member

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    Picked up this Spear & Jackson a year or so ago and never did anything with it, until recently... It is a 12" saw with 12 TPI.

    After some careful testing, the split nuts seemed fine with being removed, so I went ahead and did that. I love finding things like the original bluing on a ~170 year old saw.

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    Decided to keep that on there when I cleaned up the back and plate. Went after the handle with the intention of removing dirt but leaving the patina.

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    It has a clean logo, but the "Warranted... Cast Steel" is a bit faint...

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    There are two chips on the bottom horn, and, aside from the initials on the right side, it is in fine condition and retains very crisp detail. I'll probably leave the chips alone for now. I originally intended on fixing it up and selling it, but... I'm afraid this one isn't leaving the shop.

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    (Sorry, I didn't clock the third saw nut to appease the Split Nut gods for allowing me to easily remove and return them. I'm OK with this.)
     
  2. fred0325

    fred0325 Most Valued Member

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    It has turned out to be a lovely saw.

    BSSM does not have a mark quite like yours. The nearest that they have with regards to font and general layout is a John Spear mark and which is dated around 1850. The mixed upper and lower case Sheffield put is between 1840 and 1870, but looking at the position of the Warranted and Cast steel and the chamfered base to the back, I would hazard a guess at the earlier end of this time-frame.

    Which co-incides very nicely with your own dating.

    Now forgive my ignorance on technical matters, but the bluing intrigues me. I assume that it is the left-over markings from heating during the manufacturing process and not, as we can do nowadays, apply bluing chemically to the finished steel.

    Fred
     
    Last edited: Dec 16, 2014
  3. TKW

    TKW Member

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    Fred,

    I know very little (er... nothing?) about the history of the bluing process. I don't know when it started or when it was commonly used. I would think discoloration from a heating process would be difficult to remove, whereas a chemical coat of bluing can be removed with abrasives like 0000 steel wool quite easily. Whatever it is on the heel of the back seemed to be removed quite easily, as was noted when I went a little far with the abrasive block on the right side at one point.

    For historical evidence, in Disston's 1876 catalog, they offer the No. 4 with either a polished steel back, a brass back, or a blue back (blue being the cheapest of the three).

    http://www.disstonianinstitute.com/backsawpage.html

    So the process was definitely in use in the latter half of the 19th Century. I'll see if I can dig up any historical information on the actual process itself.

    Cheers,

    Ethan
     
  4. summerfi

    summerfi Most Valued Member

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    Very nice saw, Ethan. As you pointed out, the spines on American-made saws were frequently blued. I have an older Disston that the bluing is still rather strong on. I don't know about bluing on British saws, but it would be interesting to find out more. Your saw suggests that at least one British maker used the technique.

    Bob
     
  5. wiktor48

    wiktor48 Most Valued Member

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    Fred, what is suddenly going on here? With all dating going on this forum, sometime to an exact year, you giving us a 130 years spread? Come on...

    On the serious note, I think this crown is much later than 1850s... I would think it is closer to the end of the century... not too close though... ;-)
     
  6. Dusty Shed Dweller

    Dusty Shed Dweller Most Valued Member

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    I suspect Disston used heat to assist the folding process when making backs, which caused discolouration, hence blueing or polishing to hide the marks of manufacture.

    There are a lot of "blueing" or metal patination (colouring) processes, many originally developed for firearms and bladed weapons/tools. Aside from looking beautiful they supposedly also afford some measure of corrosion resistance. Many involve nasty chemicals (especially heavy metal compounds of copper, selenium, chromium etc), corrosive etchants/fixants and hot solutions and are beyond the home tinkerer.... the fumes can be very bad and disposal of spent chemicals is an issue. Really consider the safety aspects if you are going to try this at home.

    The standard patination process is throwing heated tools like pliers etc into oil which leaves a matt black finish. I don't like it, aside from heating up tools. Disston blued the back of their backsaws and being a "hot" blue process it is relatively penetrating and "fixed"...I have successfully reblued some using cold gun blue... but as a home tinkerer the results are patchy. Some work, some are disappointing. Some comments;

    1. Some steels just don't blue well, they may come out purple-ish, blackish, black/blue or combination of all three. A good solid bright blue seems to need a hot process and I've never got it with a cold product. Any old rusty patches or pitting colour differently and look awful under blue. Polished surfaces seems to come up best.
    2. The substrate must be degreased, seriously degreased, or it won't take. Degreasing chemicals tend to be nasty things like TCE as well, BTW.
    3. You need to apply it quickly and smoothly or the final product looks patchy. I get a small disposable brush and try to get an even coat with one of two swipes... anything more and it looks spotty (probably to do with differential etching time).
    4. Be prepared to do it, polish it up with 0000 steel wool and light machine oil and repeat it again to get an even finish.
    5. After cleaning it up oil it ASAP to even the colour and stop the rusting.
    6. The cold blue I use has nitric acid in it and selenium... it pongs and seriously scares me. I wouldn't want it on my skin, to inhale the fumes or any to get into the local creek...
     
  7. TKW

    TKW Member

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    I tried bluing one of my Disston saw backs a while ago. It looked great at first, but six months later it all just started coming off. Didn't waste much time trying to analyze why; I assume I probably didn't degrease it well enough.

    Like you, I was iffy about it in the first place, so when it didn't take, I decided to just leave it be, put a coat of paste wax on it, and spend my time on future restorations doing something else.
     
  8. summerfi

    summerfi Most Valued Member

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    I hot blued a rifle 50 years ago, and it still looks great today after a lot of hard use. More recently I've cold blued some saw backs and they don't look nearly as nice. I've used a couple different brands of cold blue and they perform somewhat differently. One is fairly blue but blotchy. The other is uniform color but more black.
     
  9. fred0325

    fred0325 Most Valued Member

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    Wiktor,

    Edited and corrected. It is a pity that the 8 and 9 are next to each other.:)

    Fred

    Also re the bluing. I sharpen axe blades using a flapper wheel on an angle grinder (apologies to the purists out there but it is so much quicker than a wetstone).

    I sometimes get a little overenthusiastic and overheat the edge which becomes blued. I can remove this bluing, which is definitely heat caused, by going back over the surface very lightly with the flapper wheel so as not to generate much heat. This does not re-grind/re-profile the edge to any noticeable extent as the pressure used is so minimal.

    Even when the bluing has gone through the steel to the other edge, I turn the blade over and remove it from the other side in the same manner.

    I assume from this that the bluing has something to do with the heated metal surface in contact with the air, otherwise I would have to re-grind the entire patch and put a notch in the edge if it went deeper.

    Fred
     
  10. wiktor48

    wiktor48 Most Valued Member

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    On Bluing and re-bluing - There is a great article on how to do this here: http://www.wkfinetools.com/contrib/bSmalser/rustproofing/rustproofing1.asp . I use the same method on restoring small bits for hand drills made by various companies. I have this method modified a bit - I keep bits in OXPHO-BLUE overnight. There are two very important steps: degreasing and rubbing with 0000 steel wool after each bath. I actually do the "rubbing" on very soft wire wheel. Degreasing is paramount after every OXPHO-BLUE bath. I repeat the whole process 3 time, sometimes 4. Results are very good.

    Fred, your example is not bluing - you simply overheating steel to the point that the temper is lost at that spot. To correct this you should regrind the edge to remove this spot. Going over the spot with a flap-wheel only removes the color. The edge however is defected.

    Here is an example of restored bits that are produced with this method:
     

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    Last edited: Dec 19, 2014
  11. TKW

    TKW Member

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    Fred, I know what that kind of bluing looks like, having done it to a chisel when I was first learning sharpening. It does it easily on your ax at the edge because the metal is so thin at that point. As Wiktor said, you have removed the temper in that spot (whether or not you buff the color out) and need to now grind past it or re-temper it before that part will properly hold an edge.

    I do not believe the color on the spine is a remnant of some process of heating it up to a certain point. We already know spines were being blued during that era; this looks like bluing, just like what I've found on the spine under every Disston saw handle I've removed.
     
  12. ray

    ray Administrator Staff Member

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    Thanks for that Ethan, nice cleanup job, it's always good to see a 160 year old saw still getting used and appreciated. The gun trade in places like Birmingham dates back well before saw making in Sheffield, so I'd be surprised if blueing wasn't a well known process at least 100 years or more earlier..

    Ray
     
  13. TKW

    TKW Member

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    Thanks, Ray! I'm really not a collector of any kind of tool, beading tools being the one exception, so I don't have a ton of old backsaws - a handful of early 20th C. Disstons, one I made myself in a Matt Cianci class, and (now) two British saws, the S&J and a lovely little Tyzack open-tote dovetail saw I picked up at the second Woodworking In America that feels like an extension of my first finger when I hold it. When I get some free time, I'll start an album so I can share pics of it.

    Thanks for setting up the environment to facilitate discussion on these great tools. I need to watch myself. I really don't want to collect tools; I'd much rather use them. But I know how easily the "bug" can bite. I've felt it before. :)

    Cheers,

    Ethan
     
  14. Barleys

    Barleys Most Valued Member

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    Lots of interesting contributions here: am away from home (in allegedly sunny California, where it hasn't stopped raining since we got here 5 days ago....) but can say from memory that Sheffield saw makers supplied saws with an optional blued back, the metal being iron, not steel at this date (agree with Fred, 1850-ish). The marks on the lower edge of the back are less deeply struck, in the manner of 'bright struck' marks on a hardened steel blade - but if what I've just said about this being iron, not steel, is true, that can't be the case, so I am puzzled (yet again).
     
  15. Curly.

    Curly. New Member

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    I was searching for info on my Spear & Jackson 12-inch 12 TPI backsaw and came across this thread about what is almost exactly my saw.

    I got mine at an estate sale for a few dollars about five years ago. I loved the way the handle fit my hand as well as the figure of the wood, but it wasn't usable. It came with only one good screw and one nut, plus two broken screws (shown in the second photo). I tried off and on over a few years via a number of different avenues to find replacement hardware, but only hit dead ends.

    In 2019 I took a class at Roy Underhill's school in North Carolina, and brought the handle and hardware along with me. Ed Lebetkin has a tool shop above Roy's workshop/school, so on the first day of class I left the handle with him to see if he had any parts that would fit. He brought it back to me the next day with a couple of replacement screws and nuts.

    I went home happy and did some refurbishment and sharpening (only the third saw I've ever sharpened). There was some not-very-visible damage to the bottom of the upper horn that I filled with a little epoxy putty and smoothed so it wouldn't dig into my hand. The screws and nuts have some damage and are not an exact fit, but I'm just glad I can use it now. It's my favorite saw.

    The logo is the same wording as Ethan's but differs in the details of letter shapes and spacing. The "WARRANTED" and "CAST STEEL" are partly worn off, but still partially visible. The logo side of the back also has initials K.E.R.

    So, I was quite pleased to come across it here, and learn a little about its probable age!
     

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  16. ray

    ray Administrator Staff Member

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    Hi Curly, Welcome to the forum, Nice saw in excellent condition, the hook in the handle always seems to add a little extra bit of elegance. There are numerous threads on S&J on the forum.

    Regards
    Ray