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Primus No.41: Full disassembly and fettle.

Discussion in 'Fettlers Master Class' started by Tony Press, Jan 7, 2017.

  1. Tony Press

    Tony Press Australia Subscriber

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    Here is the full fettle of the 1955 Primus No.41 posted in the Reference Gallery here.


    As it came:

    IMG_9684.jpg

    IMG_9819.jpg

    IMG_1193.jpg

    IMG_1194.jpg

    IMG_0014.jpg

    IMG_1202.jpg



    Disassembly

    1. The first job was to straighten the flame ring:

    IMG_1203.jpg

    I used the "beer bottle" technique to get it properly rounded...
    IMG_1205.jpg

    and the @kerophile pliers technique to straighten the flare.
    IMG_0010.jpg


    2. The second job was to remove the packing nut using a 10mm spanner.

    IMG_1208.jpg

    IMG_1209.jpg


    3. The third job was to remove the burner from the rest of the stove using a 19mm spanner.

    IMG_1215.jpg

    The first try showed that the burner was locked on tight so I applied some heat from a propane torch,
    IMG_1216.jpg

    added some penetrating oil (Note: 1:1 acetone:automatic transmission fluid is as good, if not better, than commercial penetrating oil),
    IMG_1218.jpg

    and placed the nut below the spirit cup in the vise lined with leather.
    IMG_1222.jpg

    The bottom of the burner had some heavily oxidised residue of some sort,
    IMG_1225.jpg

    as did the fuel tube and mounting nut.
    IMG_1226.jpg


    4. The next job was to take off the burner nipple (jet/nozzle) using a specialist spanner. A standard Optimus 111 spanner will work (see three photos below), but I find them more fiddly that this great little tool).

    IMG_1212.jpg

    IMG_1213.jpg


    5. After the nipple had been removed, and with the spindle still in place, I turned the burner upside down and turned the spindle to the "clean" position and the cleaning needle fell out. Note that the cleaning needle ratchet came out without the needle, which was still stuck in the nipple).

    IMG_1228.jpg

    IMG_1230.jpg

    Note that the nipple had had a hard life in the past.
    IMG_1234.jpg

    I then removed the regulating spindle with the control wheel. The spindle was in very good condition, with all its parts unworn.
    IMG_1231.jpg


    6. I then cleaned the burner using some carburettor cleaner and flame. It was not very dirty, so I did not have to do anything more than that.

    IMG_1232.jpg

    IMG_0011.jpg


    7. The next job was to remove the non-return valve (NRV) from the bottom of the pump tube.
    As this stove had not been used for a long time, I did not want to risk damaging the end of the NRV, so I used a specialist NRV tool (@loco7stove). I had soaked the pump tube/NRV with penetrating oil overnight.

    IMG_1237.jpg

    I locked the tool in the vise (note the use of a pipe cleaner to stop the sliding part of the tool from moving down the shaft),
    IMG_1239.jpg

    and carefully slipped the tank onto the tool locking it onto the NRV correctly. I then pressed down on the tank and turned the tank slowly anti-clockwise with both hands. The NRV came out fairly easily.
    IMG_1240.jpg

    Undamaged - no washer.
    IMG_1241.jpg


    8.
    I used a drill chuck to hold the bottom end of the NRV (Note to the unwary: using a screw driver in the slot at the end of the NR sometimes results in it shattering - I know this from personal experience!).
    IMG_1245.jpg

    IMG_1276.jpg

    The NRV was dirty but in good condition. The pip was very withered cork that I replaced with a Fettle Box viton pip.
    IMG_1247.jpg

    I then cleaned to pump tube with carburettor cleaner and a bottle brush. It had the remnants of the leather pump cup and lots of oil residue stuck to the tube and end. I checked to see whether there was a lead washer down there, but there was not.
    IMG_1248.jpg

    IMG_1235.jpg


    9. All the parts were all given a clean, but as I did not intend to bring this stove back to "new", I didn't use 25% vinegar, or citric acid. I soaked the tank, NRV parts, and burner parts in "Marine Clean" (but not for too long to make sure they didn't discolour). I then rinsed the tank with old kerosene and then new kerosene, and gave the burner a last blast of carburettor cleaner.


    10. Here are all the pieces ready to reassemble the stove.

    New cleaning needle (from Fogas); seals, washers and pump leather from The Fettle Box; and note that I have used a washer on the NRV.

    IMG_1269.jpg



    Reassembly

    11. Replacing the NRV with its new washer

    IMG_1277.jpg



    12. Replacing the control spindle and packing nut:

    IMG_1278.jpg

    IMG_1279.jpg



    13. Replacing the cleaning needle. There are a number of ways to get the needle in the correct position for adjustment:

    The finger (it hurts and you are prone to get a hole in your finger).
    IMG_1280.jpg

    The matchstick - but sometimes you can bend the needle.
    IMG_1281.jpg

    My preferred method is the eraser on the end of a pencil.
    IMG_1285.jpg

    IMG_1282.jpg

    NOTE: The technique for getting the needle set in the correct position is:

    A. Ensure that the control wheel is set fully to the open position (in this case turned to the right).

    B. Position the cleaning needle with the teeth facing the cog of the spindle.

    C. While keeping steady downward pressure, and ensuring the teeth of the needle remain against the cog of the spindle, turn the control wheel to the "clean" position (in this case to the left) until you hear 4 or 5 clicks (I use 5 clicks).

    D. Then turn the control wheel fully to the open position (in this case to the right) and replace the nipple.


    IMG_1283.jpg

    IMG_1289.jpg



    14. Note. When adjusting the cleaning needle, I noticed it was catching in the nipple. It was ever-so-slightly too large on the edges, so I had to file it down a little, and clean the burrs on the inside of the nipple.
    IMG_1288.jpg

    IMG_1287.jpg



    15. The trickiest bit of the fettle of this stove was getting the burner tight and in the correct position:

    IMG_1242.jpg

    I started with one washer, but ended up with two (one above and one below the sprit cup). The burner needs to be tight and the spindle facing directly to the cut out in the tin.
    IMG_1291.jpg

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    16. Refitting the pump cup with a wide screw driver and 15mm spanner,

    IMG_1295.jpg

    IMG_1296.jpg



    Now for the test burn. Note the orange elements in the flame. This will be the residues of the cleaning process.
    IMG_1298.jpg

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    IMG_0028.jpg

    And here is it set up in the tin:
    IMG_1374.jpg


    The fettle of the tin is shown here.

    (I will post photos of the painting process for the tin later).


    Cheers

    Tony
     
  2. Robert Bruce

    Robert Bruce Australia Subscriber

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    Very good explanation Tony, especially the setting of the cleaning needle. A great example and reference.

    Cheers
    Rob
     
  3. Metropolitantrout

    Metropolitantrout United States Subscriber

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    Hats off to you Tony for the thorough cataloging of this restoration!
    Well done! Jerry
     
  4. Doc Mark

    Doc Mark United States Subscriber

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    @Tony Press

    Wonderful presentation, Tony! Very well done, and I actually learned a little trick from you, in reading this. I've been trying to figure out how to make sure a removed burner lines up properly, and you have shown me how to accomplish that little task. No muss, no fuss, just good information!! Thanks, a bunch, Mate! Take care, and God Bless!

    Every Good Wish,
    Doc
     
  5. janders

    janders Norway Subscriber

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    :clap: Wonderful!
     
  6. Tony Press

    Tony Press Australia Subscriber

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    @Doc Mark

    It's good to know that I can still teach an old Doc new tricks. :lol:

    Cheers

    Tony
     
  7. presscall

    presscall United Kingdom Subscriber

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    @Tony Press
    Masterly work and presentation.

    Where'd you get the 'great little tool' to undo/tighten the jet nipple?

    IMG_3795.JPG

    @shagratork
    Trevor, given the comprehensive strip-down and reassembly on a rare model of stove, including lots of really helpful ideas and tips (the beer bottle flame ring straightener for example) Tony's post gets my vote for retention for easy future reference in the Fettler's Masterclass section.

    John
     
  8. Lighthouse

    Lighthouse Sweden Subscriber

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    I was just about to suggest that John. Immaculate write-up, detailed pictures and lots of tips 'n tricks. Yep, deserving of that!

    Frank
     
  9. richmay

    richmay Subscriber

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    Excellent :thumbup:
     
  10. shagratork

    shagratork United Kingdom Moderator Subscriber

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    @presscall
    Hi John, I have just seen this thread and my thoughts matched yours and it is now duly moved to the 'Fettlers Master Class' where it will not get lost.
     
  11. Tony Press

    Tony Press Australia Subscriber

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    Thanks for the compliments.

    @presscall

    John,

    I bought it online from the USA a couple of years ago after reading about it here on CCS. It was relatively expensive (post from US to Oz is a killer), but it has been worth every penny.

    Because it has those handle holes all the way around, you only have to fit it once to the nipple, and then you take the bar out and reposition it in a new hole. I keep it in the top draw of my fettling toolbox.

    If there was the equivalent for the smaller Primus-type nipple, I'd be in like Flynn.

    I'll see if I can dig up where I bought it from, but my recollection is that @Doc Mark has/had one, too (that he couldn't find in the Hobbit Hole).

    Cheers

    Tony
     
  12. Doc Mark

    Doc Mark United States Subscriber

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    @presscall, @Tony Press,

    Morning, Gentlemen,

    Yes, Tony, you're right. I do have those wrenches, too, and they do work very nicely, indeed! I bought both of his little brass wonders, as you used, the small and large, and two articulated wrenches that he offered, as well. Since I "lost" these, down in the Hobbit Hole, I decided to go for a rescue mission, and spent some time down there, seeking them out again, with success! YAY!!

    Here are a few quick shots of the items I have purchased from this very nice man.

    DSCN6663.jpg

    DSCN6664.jpg


    His eBay name is "40Varga", and if you would like his email, please send me a PT, and I'll send it along to you. His tools are all very nicely made, and they work nicely. Are they perfect? Few things are, but his tools come very close. You must pay very special attention to those little handles, as they do go missing, IF you're not careful! Don't ask me how I know this...... :oops: :oops: :doh: As soon as I contacted the seller, and told him of my stupidity, he very kindly and promptly sent me some new handles, at no charge.

    I checked his offerings this morning, and do not see any wrenches at this time. However, if you are interested, I'd recommend contacting him, and seeing when he will make up a batch again, and offer them for sale. John, if you don't have any luck, I would be happy to act as a middle man in obtaining items from this Gentleman. Just let me know, and if he doesn't want to ship overseas, for whatever reason, I'll be happy to help.

    Tony, once again, excellent work on your 41, and hearty congrats for having been rewarded by having this excellent post placed in a special place of honor, where it can continue to help others, for untold years!! Bravo!! :clap: Take care, and God Bless!

    Every Good Wish,
    Doc
     
  13. presscall

    presscall United Kingdom Subscriber

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    @Doc Mark @Tony Press
    Thanks Mark and Tony for the info.

    Thanks too Mark for the offer to broker a potential purchase but I'll confess sight of the tool has got me thinking about fabricating one or an equivalent myself for the fun of it. Just the inspiration I needed!

    John
     
  14. Doc Mark

    Doc Mark United States Subscriber

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    Hi, John,

    If anyone has the skills to do this, it would be you, my Friend!!! I look forward to seeing how it (they) turn out!!! Take care, and God Bless!

    Mark
     
  15. shagratork

    shagratork United Kingdom Moderator Subscriber

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    Looks like the perfect job for Ray @Longilily
     
  16. Doc Mark

    Doc Mark United States Subscriber

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    @shagratork,@loco7stove ,@presscall ,

    Hi, Trevor, Stu, and John,

    I wanted to run something past you, just to see what your take on it might be. I feel a bit odd about any of us copying 40 Varga's wrenches, and then offering them for sale here at CCS. To my way of thinking, it's OK for John to make one, for his own use. But, selling them here, seems, somehow, not quite right. IF the maker here in the US is still going to offer them, and will ship overseas, I believe we should all support the fine work he has put into doing so. IF, on the other hand, he has no interest in making more of his wrenches, nor in shipping them overseas, then that would change the equation, me thinks. I would feel equally odd about someone copying Stu's excellent tools, or Gary's outstanding lightweight stoves and kits, and have not been happy with others have copied Ross' success with The Fettle box, and gone into competition with him. Just doesn't sit right with me.

    I have sent the 40Varga a message, asking what his plans are for his wrenches, and furthermore, if he will ship them overseas, if he is, indeed, going to make and offer his tools again. I believe we all owe him at least that much consideration. What say you, my dear Friend? How about the rest of you? Any comments, or thoughts would be welcome, in this matter, and I would appreciate your sharing, should you wish to do so. Not trying to be a prig about this, but something just doesn't seem right, to me, when it comes to copying another's design, and then selling them. Food for thought, maybe.....?? Take care, and God Bless!

    With Utmost Respect and Friendship,
    Mark
     
  17. LB1LF

    LB1LF Norway Subscriber

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    What the Doc said.
     
  18. presscall

    presscall United Kingdom Subscriber

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    Fair comment @Doc Mark. I hadn't visualised a copy, just working with the concept of an improvement on the stock Primus/Optimus wrench and as you suggested, were I to do so it would be for my own use and not for sale.

    Sorry now to have initiated a drift of Tony's fine post off topic!

    John
     
  19. LB1LF

    LB1LF Norway Subscriber

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    @presscall - I didn't get the impression Doc thought that was what you had in mind; it certainly wasn't how I read your post, either! (I have to admit I got curious after seeing those photos - curious as to find out hom nimble the CNC machine at work can be coaxed into being, that is.)

    Oh, and I forgot - wonderful OP; the most enjoyable posts I see here on CCS are ones just like this - which doesn't only show the (impressive!) end result, but also the steps taken to get there.
     
  20. Doc Mark

    Doc Mark United States Subscriber

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    Hi, John, Tony, and All,

    I hope we didn't drift too far, and never intended for my comments to drift, at all. I was responding to Trevor's post, and thought it germane to the OP, since we were discussing the NRV tools. Please accept my apology, Tony, John, Trevor, and all, if my comments were out of line. Back to Tony's outstanding post, it truly deserves to be honored by including it in the Master Fettler's area!! I know that I'm proud of your work, Tony, and I'm sure everyone else is, too!! AND, I'll be referring back to this post often, as I finally get into a project involving my own 41. Mine works fine, but I've always wanted to add a proper silent burner to it, and Tony's most excellent work, and report, has made it possible for me to do so!! Huge thanks, Tony, and God Bless!!

    Sincerely,
    Mark
     

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