Primus #3 c.1959 with original cast iron trivet

Discussion in 'Primus No:3' started by Go Scout, Apr 15, 2016.

  1. Go Scout

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    Here are some pictures of my #3 with it's original 'roarer' burner part #4131. The cast iron trivet is intact, but in need of some TLC to get it looking nice and to help preserve it. I think the trivet was originally painted a gold colour from new. There are no markings on the base of the stove, but the riser tube has a date code of 204859 indicating it's manufacture as 1959 (last 2 digits). At the bottom of the burner, inside, is part number #4749 which is a restrictor, presumably to help prevent 'resonance' or a 'pulsating' noise and flame. On good advice from experienced members on CCS, I have made and inserted a brass gauze baffle in the lower part of the riser tube which should also help reduce the 'pulsating' noise and flame. The baffle is made by tightly rolling up some brass gauze to form a cylinder, mine being about 2cm tall and a 'finger tight' fit into the riser tube. Having said all this about the pulsating flame and associated noise, the stove does run happily in 'pulsating' mode. Smaller 'roarer' stoves seem less prone or unaffected by this phenomenon. It's pretty easy to work on, but obviously takes a bit more 'polish'. The pump tube is longer than normal and I found that my 'standard' sized NRV removal tool is not long enough to reach all the way down to the end. The tank cap and air bleed screw are pretty standard Primus parts, as is the leather pump cup washer. Heat proof burner washers, although available, are harder to come by than standard sized washers.

    20160415_134028.jpg 20160415_134018.jpg 20160415_133957.jpg 20160415_134324.jpg 20160415_134247.jpg 20160415_134226.jpg 20160415_134217.jpg 20160415_134127.jpg 20160415_134114.jpg 20160415_132024.jpg

    Here are some more pictures, more to do with the burner head and the restrictor part #4749, mentioned in the text above.

    20160414_095637.jpg 20160414_081459.jpg 20160414_085804.jpg 20160414_084729.jpg 20160414_084718.jpg

    And finally, some YouTube clips with the stove running straight after fettling

    1) Warming up
    2) Full throttle
    3) Shut down



     
  2. kerophile

    kerophile United Kingdom SotM Winner Subscriber

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    Hi, I believe that the noise you get from your No.3 is just normal for this stove.
    With a stated fuel consumption of about 1 litre per hour it has a maximum theoretical power of around 10kW, or approx 4 times more powerful than a No.1 or No.5 Primus/Optimus designation stove.

    Some of that power comes as noise, and that "fluttering" tone is not uncommon with these large burners.

    I was using this set-up to melt lead for fishing weights today:

    https://classiccampstoves.com/threa...fitted-to-monitor-78-stove.26806/#post-272938

    This burner is also noisy.

    Best Regards,
    Kerophile.
     
  3. Go Scout

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    Hi Kerophile

    Thanks ever so much for your kind advice and help with my fettle, it's greatly appreciated. I think my stove is running as well as I can get it and the fluttering is easily at an acceptable level. I've just got to sort out the trivet which seems quite intricate and deserves a bit of extra care and attention to do it justice.

    Nice Monitor stove by the way! My 2 pint Monitor, which came with a silent burner, now sports a Liberty roarer burner, which fits well and runs beautifully. I'll probably leave it in place and retain the original burner in the stove box (when I make it).

    My Primus #10 temporarily had a Liberty #2 silent burner fitted, but the thread was a little bit on the tight side. It ran just fine. Having now cleaned up the original Primus burner, I have now swapped it back to original condition and it now runs lovely, but with a slight leak from the old burner washer. New washers have been ordered from The Fettlebox and should be with me soon. My Primus #5 is also awaiting for the same envelope to arrive as I ordered washers for it too.

    Thanks once again for your invaluable help

    Best regards

    Baz
     
  4. threedots New Zealand

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    Hello Baz.
    Great topic, a nice stove and excellent photos. :thumbup:
    I like the trivet as well.
    Cheers, John
     
  5. Go Scout

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    I have to admit to being rather embarrassed or shamed into photographing a rather sorry looking trivet. It is indeed a work of art in itself, with lots of fine workmanship gone into it's making. The casting is of fine quality and quite thin, and I imagine that it was skilfully made.

    My neighbour, 2 doors along, has been restoring a Mk2 3.8 litre straight six Jaguar that he saw rusting away in a field. I have been following his restoration with interest and have even been called upon from time to time to offer a bit of help here and there. The Jaguar is now finished and is in 'show room' condition after much welding and tears. Fine job by a very clever neighbour - nice grit blasting booth he has . . .

    Today, I went round to see him. "Do you know anywhere around here where I can get this grit blasted?" I ask casually holding up the trivet, whilst sipping a cup of tea in his kitchen :whistle:

    "That's a fine bit of ironwork" he says, admiring the sorry looking trivet I'm holding up. "As it happens, I have a small booth in the garage and I'll be happy to do it for you"

    Tah dah! Correct answer I thought. Of course, it does mean a trip to his garage, where we stand and discuss the Jaguar for a good hour or more, including starting the beast up and listening to it purr away. Anyway, a very fruitful visit to see the Jaguar I thought, as I returned home.

    Now indoors, I'm frantically searching for heat proof gold paint on Google. I've come across some good stuff I reckon that is sprayed on, allowed to 'air dry' and then cured by baking in the oven (when the missus is out and the extractor fan running at full blast of course!). Best get that order placed, as I don't want pristine, ready to paint trivet going rusty again!

    Baz
     
  6. Tony Press

    Tony Press Australia Subscriber

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    @Go Scout

    If you are going to use the stove/trivet, don't bother with the paint. I now "cure" my cast trivets like I would a cast pot: clean them, paint the with olive oil, and bake them in the oven for 2 hours at 150C (checking and reoiling in the process of baking).

    The trivet can then be used and re-oiled if needed from time to time.

    Cheers

    Tony
     
  7. Go Scout

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    The neighbour brought the trivet back :cry:. He'd done about 1 inch square and decided that his machine wasn't working properly etc., etc.

    Much phoning around and emailing pictures also failed to secure someone willing to grit blast it.

    Out with my Como drill (Dremmel type thing) and many hours of tedious work eventually found me spraying it with "gold" stove paint, supposedly good upto 900 degrees C or something.

    Now, if I imagine 'gold' paint in my mind, a sort of, well ...... gold colour appears, not a sort of ....

    ... well, make your own minds up, but that's it, this is the colour it's staying. It's been baked in the oven for an hour at gas mark 8, which I think is about 230 degrees C. It certainly looks better than the rusty old thing it once was, pictured above.

    20160421_164126.jpg
     
  8. Go Scout

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    Maybe worth a mention? Look carefully at the 2 pictures of where the trivet is seated on the pan supports. The measurement between top of support to top of trivet is 1/2" - so a pan would be 1/2" higher above the burner when the trivet is used. Don't know if this makes any difference, but thought I'd mention it anyway.
     
  9. Go Scout

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    Some recent pictures of the same stove and trivet, now with a storage box. The trivet looks like it could do with a touch up as some rust has flaked some of the paint off. The box was made to be sturdy enough to sit on as well as protecting the stove. The prickers are Primus in origin, part number 4751 and are for the 0.6mm jets used on this stove.

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    The other stoves (all Primus) are a #96, #5 and a #10 and give an idea of the size of the #3. The wind shield has been fashioned from a piece of boiler flu pipe.