Svea No. 14

Discussion in 'Svea No:14' started by Ben Hall, Sep 28, 2021.

  1. Ben Hall

    Ben Hall United States Subscriber

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    Here are some photos of my latest acquisition, a Svea Number 14. It's another purchase from the e-place and again, I probably paid too much, but it looked like it needed a loving home. ;) As will be seen in the photos, it's not the rare tubular burner, but is the later style burner made in similar fashion to the silent burners we're all familiar with. Based on what I've read here, this stove is likely post 1915 but having the external NRV, is pre-late 1930's maybe even early 1940's.

    svea14-01.jpg
    Eagle-eyed viewer will immediately note the missing inner flame spreader and the missing burner "top cap." This went into the purchasing decision, so I did pay less for this stove than I would have had it been complete. I figured at worst, I could cobble something together.

    svea14-03.jpg

    svea14-06.jpg

    svea14-07.jpg In this photo, you can see the amount of baked-on carbon present on this burner...along with a nice layer of dust and dirt. It's clear that this stove has not been fired for a very long time...and that the last time it was fired, it likely was not running properly and did not get the burner hot enough to burn that carbon off.

    svea14-08.jpg
    Something I will say about these stoves of this vintage is that the craftsman ship is always pretty good. Look at the consistency of that solder seam on the bottom of the tank - quite nice.

    svea14-09.jpg
    Now the question came as to what to do about the missing inner flame spreader and the top cap.

    CCS user "Twoberth" had a very interesting post about modifying a plumbing fitting to work as an inner flame spreader.

    Makeshift Primus No. 4 inner cap

    This was such an excellent idea that I copied the idea, but instead of a brass fitting, I found a steel fitting in my box of "junk parts" that I keep for times like this. :)

    So what what started as a steel hex reducer that looked like this:
    Screenshot 2021-09-28 110626.jpg

    Was...after some cutting, drilling, filing, and grinding...became this:
    IMG_5383.JPG
    Note that in this picture, the fitting appears to be copper. It's not, it's steel, I'm just terrible at proper color corrections with my camera. :(

    Inserted into the burner...it looks okay:
    IMG_5387.JPG
    And in this photo you can see that the insert is steel...and that I did a lot of working cleaning up the burner. Usually, I don't like to clean things up this much, but since I wanted to get some accurate measurements for another purpose (more on that later) it was needed.

    Now the question was - what to do for a cap? Rummaging around my garage, I found an empty can of PB Blaster. This is an aerosol penetrating oil common in the Southern USA. (It may be common elsewhere, but I don't recall seeing it on the shelves in stores in the Northeastern USA when I lived there.) The "dome" of the bottom of the can looked like it would be perfect. So I cut out the bottom of the can, made a little "form" on my 3D printer, and after some careful cutting, trimming, bending, and hammering...created this:

    IMG_5384.JPG

    IMG_5386.JPG
    When installed, the whole thing looks obviously home-made, but not terrible!
    IMG_5388.JPG
    Certainly, both the homemade inner flame spreader and top cap are of good enough design / quality to support a test firing of the burner and stove to check for other issues.

    Earlier I noted that I cleaned the burner up because I wanted to get some good, accurate measurements. That's because using Mr. BernieDawg's 3D printed metal burner caps as inspiration (see YouTube BernieDawg Cinema channel) I figured I could design up and having Shapeways 3D print up some much better looking, better designed pieces.

    Inner flame spreader part:
    Screenshot 2021-09-28 103843.jpg

    Screenshot 2021-09-28 103942.jpg

    The above design is very loosely based on a flame spreader for a "number 1" size burner that's been scaled down to fit the Svea 14 burner. While the originally was stamped from sheet steel, this is a lot thicker, almost 2mm, as I'm not sure how well 3D printed metal will work with a thinner section.

    And the top cap:
    Screenshot 2021-09-28 103903.jpg

    Screenshot 2021-09-28 103922.jpg
    The shape is based off of a patent drawing from a tubular burner found here on CCS plus some consideration for the 3D printing process needing a thicker cross-section than the original that was stamped from sheet steel. The two "nubbins" that can be seen (four total) are to allow the cap to sit evenly in case it is a little large in diameter. That is one thing I'm fairly uncertain about when it comes to 3D printing metal - what sort of tolerances can I expect?

    One of the issues with 3D metal printing is that it still is fairly expensive. Both parts above printed in "steel" by ShapeWays is about $80 USA total (2021 prices) including taxes and shipping. If the homemade parts I've built work fine and show that the stove has no other problems, I may try it out. :) Of course, it may be that the homemade parts work well enough that I don't try it out either! ;)

    Thanks much,
    Ben
     
  2. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi @Ben Hall Great Work and good photos and diagrams.
    The problem has been tackled before and I recall that use was made of later cap designs to “donate” parts for the replacement of missing parts.
    The top section of an outer cap from a silent burner provided the top cap for the outer perforated element.

    It is possible that a later inner cap might fit your burner requirements....

    In this old post of some silent caps I provided dimensions:

    Which Primus caps???

    It might be worthwhile examining the possibility of transplants before following the costly 3D metal printing route,

    Best Regards,
    Kerophile.
     
  3. igh371

    igh371 SotM Winner Subscriber

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    @Ben Hall Another method of making a No.4 inner cap is to modify a standard domestic plumbing copper pipe end stop piece, see here.
    Top covers for those old type silent burners can be made from suitable size engine core plugs (e.g.), but I think your homemade one will work perfectly well too.
    3D printed, however, that is really intriguing, be very interesting to see how that would work.
    Ian:thumbup:
     
    Last edited: Sep 28, 2021
  4. Ben Hall

    Ben Hall United States Subscriber

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    Greetings all! Thanks much for the replies, much appreciated!

    @kerophile - thanks much for the link to the thread with the inner and outer cap measurements.

    It appears that an inner cap for a Primus No. 4 stove would be a perfect fit without modifications...and that an outer cap also for a No. 4 could be made into a nice top cap for the Svea No. 14 burner. I'll have to be on the lookout for both!

    @igh371 - a copper pipe end cap would also work very nicely. The next time I'm at the hardware store / home improvement place I'll have to see what they've got in stock if the one I have fashioned from a hex reducer doesn't work well.

    I really like the freeze plug idea! I'll have to check that out as well. The freeze plugs I'm familiar with here in the states are steel and are of nice thickness, perfect for a top cap. I'll have to see what is available here in the USA, I seem to recall that the ones I've used in the past were pretty flat, without any dome at all? Without the dome, I don't think they would clear the spigot in the number 14's burner?

    Correction / Edit / Update: Appears that freeze plugs in the USA are somewhat flat and not domed, but do have rounded edges so the plug would sit a good ways off the top of the burner, not blocking air/fuel flow.

    Certainly, one concern I've got about my homemade one is that it is made from thin steel, about 0.3mm.

    For sure, anything homemade or modified from plumbing parts or auto freeze plugs will be a lot cheaper than anything from ShapeWays! :)

    thanks much!
    -ben
     
    Last edited: Sep 28, 2021
  5. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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  6. Dean

    Dean United Kingdom Subscriber

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    @Ben Hall @igh371
    I have a good range of sizes of core plugs - all new old stock.
    Don't ask why!
     
  7. Ben Hall

    Ben Hall United States Subscriber

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    I've spent about the last hour looking at core plugs. Found one that looks like it might be close:

    Dorman Products - 555-029

    Ten of them from Amazon are $15 US delivering to me on Friday. :) It is quite possible that the ID is going to be a little large, but I figure I can use the trick shown in one of the shared links and do a little silver brazing of a piece of sheet brass to make up the difference. :)

    Thanks much y'all!
    -ben
     
  8. Ben Hall

    Ben Hall United States Subscriber

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    This evening's test burn was not an outstanding success. Lots of soot and yellow flames as can be seen below. I suspect that my top cap is too flat, is restricting flow, resulting in a rich, yellow flame versus the blue flame we'd like to see with good combustion. More experimentation is in order! :)

    Photo-0.jpg
    In this photo, the flame actually looks a lot better than it really is. The camera is not doing a good job showing the yellow, likely due to the sun being low in the sky.

    Photo-1.jpg
    This shows it better, but still doesn't match what I see with my eye. The burner also appears bent in the photo, tilted towards the camera, and I can confirm that is real. I think some of it may be that the riser tube is bent, but for sure, the burner is bent too.

    Thanks much,
    ben
     
  9. Tony Press

    Tony Press Australia Subscriber

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    @Ben Hall

    You can straighten the burner by clamping the hex in a vise, and very gently pulling it by hand back to vertical. You can do similar to the riser, with your knees as the vise.

    If the burner is not leaving soot that can be wiped off with your finger on the pot, your burner is ok.

    Cheers

    Tony
     
  10. ally

    ally Subscriber

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    the ingenuity never ceases to amaze

    nice work!

    :)
     
  11. Ben Hall

    Ben Hall United States Subscriber

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    @Tony Press - sounds good on the vise straightening method, will give that a shot today hopefully. Unfortunately, it is leaving soot on the pot that I can easily wipe with a finger:

    soot.jpg
    I'll be fashioning a taller top cap sometime today from the bottom of a spray paint can while I await delivery of the core plugs. :)

    thanks much,
    ben
     
  12. Ben Hall

    Ben Hall United States Subscriber

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    Good afternoon all,

    So I quickly fashioned up another top cap with additional height that would give less resistance to air and fuel flow. As you'll see in the photos, it's rather crudely thrown together just for test purposes. The good news is, this seems to have worked! Nice blue flame now, with just a touch of yellow every now and then. :)

    Photo-12.jpg

    Photo-11.jpg

    Unfortunately since it was sunny out and I only had the cell phone camera, the blue flame is very hard to see but it is there. :)

    Tomorrow I may get some of the freeze plugs in the mail, we'll see.

    Thanks much,
    ben
     
  13. Ben Hall

    Ben Hall United States Subscriber

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    Greetings all,

    The freeze plug (expansion plug) suggestion was right on target! In today's UPS delivery there was a box containing 10 Dorman 555-029 steel expansion plugs. They were too small to go over the burner, but the exact perfect size for a piece of brass to act as a guide! In one of the posts referred to above, another member did the same thing, but silver-brazed the guide on to the cap he was making. I don't yet have silver-brazing equipment, so I instead used three stainless steel 4-40 screws, lockwashers, and nuts. Here's photos:

    newcap1.jpg

    newcap2.jpg

    newcap3.jpg

    Not too bad! Probably a little too tall, but should work fine. I'll test fire sometime tomorrow, it's fixin' to rain outside here.

    I'm going to create a new post with additional info in the Fettling Forum. :)

    Thanks much,
    ben