Questions about US made Early Primus.

Discussion in 'Stove Forum' started by Doc Mark, Jul 19, 2020.

  1. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Greetings, Friends,

    Today, I got out three early stoves, which are very similar to one another. Only one of them is marked in any way, and those markings are on the fuel cap. Otherwise, there are no additional markings, or engravings, on the stove body of any of the three.

    Here is the fuel cap from early Primus, compared a fuel cap from one of the other two stoves.

    IMG_5076.jpg

    The other two stoves are similar to the Primus, but not enough to make me think they were made by that company. In truth, I think the other two were made by Khotal, or another such company. The Primus is just better made, with much better fit and finish, IMHO. Also, the other two stoves both have the pump tube setup that needs to be removed from the stove, in order to service the NRV assembly, whilst the Primus has what looks like a standard NRV, or something very close to it.

    So, here are my questions: It appears that Primus did engrave many models of the US made offerings, though some others were not engraved, other than their fuel caps. Were the non-engraved models the earlier ones, or the later ones?

    And, please take a look at this pump bucket setup.

    IMG_5075.jpg
    The glop of solder on top of the retaining nut, "looks" like it's just soft solder, to me. I gave thought to using a solder sucker, and a torch, to remove that, so I can service the pump bucket. But, I don't want to damage any of the thin brass parts of this setup. What are your thoughts, please? Does that look like soft solder to you, too, or brazing? Do you think the torch and solder sucker would work OK, without damaging any other parts?

    The burner on this stove is original, as is the inner cap. But the original outer cap was missing when this stove was sent to me. I installed a steel Optimus cap on it for the time being, until I can source a Primus replacement that is at least close to how the original cap would have been.

    So, what are your thoughts on this, Fellow Stovies? I look forward to hearing what you have to say about this stove, and servicing the pump bucket! Thank you, very much, and God Bless!

    Every Good Wish,
    Doc
     
  2. Tony Press

    Tony Press Netherlands Subscriber

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    I’m not familiar with the yankee Primus, but the blob on that pump looks like soft plumbers solder. I would use a very hot soldering iron to melt it, rather than a torch. If that’s not possible, I would use a small torch with a fine pointed flame.

    Cheers

    Tony
     
  3. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Evening, Tony (@Tony Press ),

    Thanks, that's very good advice! I do have a very large, electric soldering iron, and I'll dig it out, and give it a go. What about a solder sucker? Once the solder begins to flow, the sucker it placed up against it, and triggered, whereupon, it sucks up the liquid solder. I'll see how that works and report back here! Thanks, very much, for your always good advice, and counsel, my friend!! Time to hit the sack, up this way, but I need to do the dishes, first. SB taught an online class today, so I cooked, and will clean up before hitting the hay. I'll, of course, tuck her in, first. Have a great day, and God Bless!

    Every Good Wish,
    Mark
     
  4. Wim

    Wim Subscriber

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    To make sure the solder is the soft type, try to "cut" it with a sharp knife. It will easily enter soft solder but hardly scratch any "hard" type of solder. I am pretty sure this will be soft solder as otherwise, putting it on, the leather cup and thin brass items would be damaged by the heat to apply it.
    Another option would be a bastard file. No heat needed! (Both for testing or removing the blob)

    ATB,

    Wim

    @Doc Mark
     
  5. cottage hill bill

    cottage hill bill SotM Winner Subscriber

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    Mark,
    If it's soft solder (betting it is), I'd heat it with a micro torch and when the solder gets soft give the pump rod a sharpish rap on the edge of the work bench. Most of the solder will fly off. Re-heat and wipe the remaining solder off with a wet rag or wet paper towel. that should get enough of it off to disassemble and clean up. You could also use one of the wooden handled, stainless bristle brushes that are about the size and shape of a toothbrush.
     
  6. presscall

    presscall United Kingdom PotY Winner SotM Winner SotY Winner Subscriber

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    @Doc Mark
    Hi Mark.
    I’ve had stoves with the pump cup assembly retaining nut intentionally burred over and removal entails separating the pump cup retaining washer nuts in situ, unscrewing the pump knob and sliding the large diameter pump cup washer retaining nut off the pump rod, ditto the washer and replacing a washer with that process in reverse. Takes a lot longer to write than do!

    John
     
  7. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Hi, Guys,

    Many thanks for your great suggestions! I tried the only bastard file I have, which, unfortunately, is old and very worn (bought used). It did take off some of the solder, but not enough. Then, I used a brass bristle brush, and that worked a little, but still, not enough. I got out my Demel tool, and used a spinning steel brush. Again, nothing, so far, as removed enough solder to make the nut accessible. The only torch I have is a huge one, and even IT didn’t do too much. I was afraid to use too much heat, as I didn’t want to melt the thin brass parts. John’s excellent idea would have worked, except for one fact: the guy who soldered the nut, also soldered the back washer to the rod!! HOLY MOLY!!

    A74E5DBE-5236-48E7-A6FC-E836B4D4588F.jpeg

    D9B394A7-675F-49AC-9C40-981D2E5DC0B4.jpeg

    7FCE440D-299C-4576-82E6-1D72CF4B7DD6.jpeg

    6139FAA2-519D-4CFB-938D-366C993C9AB9.jpeg


    You can see the leather smoking, in that last photo!! Guess I’ll have to buy a new Bastard file, and/or a Micro torch, in order to get this job done!! Thanks to one and all for your excellent suggestions! Every one was worth trying, and in the end, I am confident that I’ll get this pump bucket replaced!! Many thanks, and God Bless!


    Every Good Wish,
    Doc
     
  8. The Warrior

    The Warrior United States Subscriber

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    Wow, they sure didn't want that leather to come off, haha.
     
  9. presscall

    presscall United Kingdom PotY Winner SotM Winner SotY Winner Subscriber

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    Now that’s excessive.
     
  10. ArchMc

    ArchMc SotM Winner Subscriber

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    Wow. So much for any hope of field repair.

    ....Arch
     
  11. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Morning, Guys,

    Yeah, I, too, thought all that solder was a bit "over the time", and definitely excessive!!

    Any suggestions as to a good micro torch that I might buy? I'll look on "the bay", but our local Ace does not seem to carry that sort of stuff. I'm afraid to use more file work, as I don't want to damage the threads of the pump rod. Thanks for your comments, my friends, and thank you all for your excellent suggestions. Had a previous owner of this old Primus not gotten to heavy handed with the solder, I am certain this Old Timer would have been up and running long ago!! Talk later, and God Bless!

    Every Good Wish,
    Doc

    PS- @ArchMc , Mac, you bring up an excellent point. NO field repair possible, with all this solder!! SHEESH!!
     
  12. roby03

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    Hello Doc

    Sometimes I use this solder removal wick. Its a soft cooper braid. One heats up
    a soldering iron, then press the cooper braid against the solder you want to remove
    with the hot iron on top of it. The solder will be sucked up into the braid, pull
    it away and let it cool for a moment, then snip that part off and repeat till most
    is cleaned off. Sometimes I heat solder then used compressed air from a can to blow
    it away. Of coarse its under a piece of glass. Eye protection!

    Hope this might help.

    Good Luck....Roby
     

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  13. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Hi @roby03 ,

    I'd forgotten about solder wick! I've got some in one of my tool boxes, and I'll definitely dig it out, and see how it works, once my Micro Torch arrives, which should be tomorrow!! Great idea! Thanks, for reminding me of that product! Take are, and God Bless!

    Every Good Wish,
    Doc
     
  14. threedots

    threedots New Zealand Subscriber

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    Hey @Doc Mark . That brass washer is supposed to be soldered there where it is. It along with the leather washer in front of it and between the brass pump cup holder provide an air tight seal on those older pump rods. I hope you haven't desoldered it yet. John
     
  15. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Morning, @threedots ,

    John, thanks for the head's up! CCS to the rescue, once again! So, I'll leave the brass washer as it is, and continue to focus my energies on removing the solder lump from the pump bucket nut. I have to other stoves like this, and will check their pump rods to see of they, too, are soldered in the same manner. Since their NRV's are of a completely different type, their pump rod assemblies are very probably different, too. Thanks, again, John! Much appreciated!

    Doc
     
  16. Doc Mark

    Doc Mark SotM Winner Subscriber

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    Morning, Guys,

    The new micro torch arrived yesterday, but I didn't get a chance to fill and test it. Hope to do that, today. I also found that my old Novy Formaldehyde Generator has a spare brass part hanging from it's windscreen, put there by some previous owner, possibly our own @Jim Henderson . This is the part I was worried about melting, when using my big torch. Now, if the micro torch doesn't work, I'll go back to the big boy, and "damn the torpedoes"! :shock: :lol:

    Here's that part:

    IMG_5088.jpg

    I'll use that part, if necessary.

    I also removed the pump rod assembly from an unmarked stove like this old Primus, and that set and the one from the Primus are almost identical!

    IMG_5091.jpg


    Whilst the Primus rod has it's retaining nut soldered in place, the other rod is just peened in place, which seems a much better idea.

    IMG_5092.jpg


    You will note that both rod assemblies DO have the rear washer soldered to the rod! The unmarked setup only had a tiny daub of solder, however, compared to the mess on the US Primus rod! And, the washer on the unmarked rod has worked it's way free of the solder, and can rotate a bit. Still enough solder is there to hold that washer in it's proper position.

    IMG_5093.jpg

    Primus rod setup on the left, and unmarked setup on the right.

    IMG_5094.jpg



    Using a proper wrench, with the rod clamped a vise grip, I tried to unscrew the peened nut. It worked!! With just a bit of pressure, the peened over edge broke, and the nut unscrewed fairly easily. The edge came free, and just became a bit of detritus which is easily removed.

    IMG_5095.jpg
    IMG_5096.jpg

    So the upside in all this, is that IF the Primus rod becomes unserviceable, I can easily add a new pump bucket to the unmarked stove's rod, and use it with the Primus stove! I am HOPING that I can bet both the old Primus, and the other stove, up and running, and that is now my goal! We'll see how it turns out! Talk soon, and God Bless!

    Every Good Wish,
    Doc
     
    Last edited: Jul 23, 2020
  17. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi Doc, a similar part to the one you show a photo of is available from Base Camp

    upload_2020-7-23_17-42-46.jpeg

    46S Spreading Spring for pump leather, keeps leather in contact with pump bore and improves pump performance. £ 2.45 GBP.

    Best Regards,
    Kerophile.
     
  18. Doc Mark

    Doc Mark SotM Winner Subscriber

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    @kerophile ,

    George, many thanks for that info! As it turned out, I finally succeeded in removing enough solder, using a new micro torch, to remove the nut. I'll save that info, and photos for later posting in the Stove Reference Gallery, and will include all the photos heretofore posted in this thread, too. Thanks, again, and I'm hopeful that this old Primus will be working again, soon! Take care, and God Bless!

    Every Good Wish,
    Doc