Sea Anchor woes (generator foot valve?)

Discussion in 'Fettling Forum' started by Adrian, Oct 14, 2020.

  1. Adrian Romania

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    To cut it very short, the lamp turns into a raging inferno when the valve control disc is turned with the arrow down. If turning it up (so the valve should be closed) the lamp works almost normally (pulsates badly every second but works).

    I took apart the control mechanism, the eccentric block is being moved correctly so the only thing I haven't disassembled is the foot valve. Can this be a case of a weak spring?

    When testing with the lamp cold the valve cuts off the fuel just fine.
     
  2. Adrian Romania

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    Update: generator foot valve no longer holds even with the lamp cold. It takes only a few pumps and the fuel starts bursting trough the jet.

    I will try to get some 99% alcohol and preheat with zero pressure in the tank, then build up pressure and see how it goes.

    Can it also be that the jet is enlarged and the needle in the off position helps restrict the fuel flow? (given the fact that the gen foot valve is allowing fuel to go up)
     
  3. JEFF JOHNSON

    JEFF JOHNSON United Kingdom Subscriber

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    The most likely cause is an enlarged jet or it may be loose or both.
     
  4. Adrian Romania

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    Foot valve was a very easy fix, just unscrewed the bottom gen, took apart the valve and discovered that the gasket had jumped out of it's place on one side. Flipped it over for good measure and it now seals perfectly. Lead washer still sealing well.

    Sadly it didn't helped one bit with the other problem, either the jet is way too large or the preheater torch is not working properly despite the flame looking good. I will try tomorrow to get some 99% alcohol and heat it up using the preheater cup.

    Th fact that it sort of worked when the foot valve was malfunctioning and the needle acted like some sort of restriction to the jet makes me believe that the jet may be badly enlarged. Don't know why would it happen tho, it was turned on maybe 5-6 times since changing it. Maybe the material is too soft and the needle enlarges the jet too quickly trough normal action? (looked at it using a magnifying glass, no rough edges near the top).

    Jet is not loose, was installed using a drop of dishwasher soap on the threads, checked it already.
     
  5. Fireexit1

    Fireexit1 United Kingdom Subscriber

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    Hi @Adrian. I had a similar issue with an optimus. It turned out that I had managed to get the excentre (the rod that connects the knob to the rod - part 105 on a petromax diagram) in the wrong place on the conducting rod connector (part 103). If the seal is good at the base of the vapouriser and it still lets fuel up then it is not closing properly. In my case it was prevented from closing by the incorrect position of the excentre - sometimes.
    The other issue does sound like insufficient heating or a poor condition jet, but as the jet is new it is probably the poor heating.
     
  6. Adrian Romania

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    Thanks for the advice :) I double checked that too when sorting out the generator foot valve. The whole assembly works as designed now. I even added some aluminum foil around the rod in the restriction area so the fuel is properly directed trough the Preston loop.
    It's most likely an enlarged jet but will get some alcohol tomorrow and test the preheating too. Can't get another jet locally so the replacement (and the needle) will have to wait a bit.
     
  7. MYN

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    You can still preheat it with a propane torch if the right alcohol is not available. Be gentle though on the heating or you'll melt a mess out of the vaporizer.
    That's only to verify if the reason was inadequate preheat or a worn jet....while waiting for the new jet to arrive.
     
  8. Adrian Romania

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    I got 99% technical alcohol (a mix of meth, ethanol and isopropylic) today (had to drive almost 1 hour in total for a product that costs 1 pound / 0.9L ) but the issue doesn't appear to be the preheating. Got the same big orange flames after burning 2 full cups.

    I'll see how it turns out after getting my hand on new jets, may be able to test sooner then expected. :mrgreen:
     
  9. Adrian Romania

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    Well, I purchased a totally messed up Anchor 350CP clone (old style, no rapid torch) which also came with a bunch of much needed spares, including two 500CP and two 350CP new jets. It was cheap and also came with about 25 mantles. After about 4 hours of cleaning, tinkering, straightening the upper generator and whatnot I got this one to work just fine.

    However the Sea Anchor is still a raging inferno, tried it with the upper assembly of the Anchor (J tube, mixing chamber, ceramic burner) and with a brand new 350Cp jet.

    Last thing to try is to use on the Sea Anchor the jet that worked on the Anchor. Will try this one tomorrow. I'm also considering the possibility that some fuel is escaping trough the jet threads, despite the jet being screed in as tightly as possible.

    Any other ideas?
     
  10. Matti Kucer

    Matti Kucer Sweden Subscriber

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    I sometime needs to use some exhaust mounting paste there, i seals perfectly.

    Matti
     
  11. Adrian Romania

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    Thanks Matti, I'll try to get some.
     
  12. Henry Plews

    Henry Plews Subscriber

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    Nickel or Copper based grease also works.
     
  13. Adrian Romania

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    Like the one used for squealing brakes? (on the bottom of the piston and so on)
     
  14. Henry Plews

    Henry Plews Subscriber

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    Yes.
     
  15. Adrian Romania

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    Well, it wasn't the jet, as I installed the old 500CP jet and needle on the Anchor lamp and it works. Has a halo around the mantle so it is running a bit rich but it works.

    350Cp new jet (working on Anchor) produces the same raging inferno on the Sea Anchor. At this point I suspect either a leak on the upper gen (maybe a crack that opens up on heating, as I tested the damn thing when cold and it holds air for as hard as one can blow into it) or fuel leaking past the jet thread.

    It is worth mentioning that the alcohol assembly on the Sea Anchor doesn't appear to work very well as the high flame from the tube is rather erratic. Now sure what other method should I try for pre-heating?
     
  16. MYN

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    Its interesting. I've experienced the elusive hairline crack on one of those Preston loops before. They would hold while cold and only open up when they reach operating temperatures. You could well be pretty close to ascertaining the cause of the inferno. How about checking out the vaporizer? I won't be too surprised even if the loop is somehow obstructed and most of the fuel short-circuiting straight through the constricted part of the generator.
     
  17. Adrian Romania

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    Well, after about 2 hours of flawless work, the Anchor started to pulsate badly. I turned it off, then upon attempting to restart it ... bam... orange flame inferno, leak on the glass near the jet area, the full works. Keep in mind that it was using the 500CP jet of the Sea Anchor.

    This pretty much provided the much needed hint. I checked the jet and it appeared to be as tight as it gets. Regardless of it I removed it, installed the 350CP jet of he Anchor and tadaaa it's so bright you cannot see the needle on the pressure gauge.

    It looks like both jets that came with the Sea Anchor (500 and 350CP) have a tendency to start losing pressure around the threads. Now it's time to test the Sea Anchor with another jet.

    As a side note, while both being Chinese clones the Anchor appears to be clearly better built then the Sea Anchor. However the Sea Anchor uses the same thread on the needle as the genuine Petromax while the Anchor has a slightly smaller thread on the rod.

    And among the various bits that came with the Anchor there are two brand new jets which have a clearly different thread. Both are labeled Petromax but the inscription is very crude and I suspect these would fit yet another Chinese clone.
     
  18. Adrian Romania

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    So, it turns out that the Sea Anchor does the orange inferno regardless of the jet used. The top with the J tube works when used on the Anchor so there are two remaining hypothesis:
    1. Failure to pre-heat
    2. Crack on the upper generator that only opens when hot.

    I tried to test the Sea Anchor using the upper gen from the Anchor and it worked VERY dim. Apparently the rod from the Sea Anchor is thicker then the rod on the Anchor so the test was somehow irrelevant.

    Any other idea?
     
  19. MYN

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    What about the other basics? For instance, insufficient air gap distance between the jet and the J-tube inlet.
    If there is a crack in the vaporizer, you'd notice a tiny yellow flame at the point of fuel leakage and the it'll likely pulsate as well.
    I'd assume you've eliminated the chances of leakage at the treaded part where the jet fits into the vaporizer with copper antiseize compound or similar stuffs. If it still leaks after a while, you could wrap a piece of mantle tie string, smeared with copper slip around the jet's threads and screw it in tightly.
    If the height of the cleaning needle is not correct(too high up) when you were using the Anchor generator on the Sea Anchor, it'd be dimmer than usual due to insufficient fuel flow. The needle needs to completely clear away from the jet orifice when you lower it by turning the pricker wheel. Otherwise, the orifice would be partially obstructed and you'd get a frayed or skewed fuel stream, which wouldn't draw sufficient air into the J-tube. You should be getting a sharp, straight fuel stream from the jet when you lower the needle.
     
  20. Adrian Romania

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    Finally I have some success: I transplanted the upper generator and the top assembly with the J tube from the pulsating/breathing Anchor to the Sea Anchor, keeping the original Sea Anchor rod in place. I also placed a copper wire around the rod.
    The result is a working lamp, even if the Leidenfrost effect is still present. No orange halo, no abnormal sounds, the working sound is calm and even. The pulsation is also different, very short.
     
  21. MYN

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    Congratulations for the success but what are the actual dimensional or other differences between the two sets that could be relevant to the problem?
    It'd be great if the exact cause of the problem for this case be known and specifically remedied.
     
  22. Adrian Romania

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    No difference whatsoever except for the fact that the Anchor upper gen is quite far bent forward and it matches the hole in the Anchor "hat" that holds the J tube. So in order to install the Anchor "hat" on the Sea Anchor after I transplanted the Anchor upper gen I had to loosen the central screw and move the lamp body a bit. Otherwise the hole in the "hat" would not align with the jet.

    Hope it makes sense.

    Now, keep in mind that the Sea Anchor wasn't working (orange inferno) due to a suspected hairline crack in the upper gen. The foot valve and the whole rod plus the rod control assembly were in good working order.

    The problem of the Anchor clone (Darth Vader breathing and strong pulsation) remains to be solved.
     
  23. Adrian Romania

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    So the hairline crack on the Sea Anchor upper generator is confirmed. I pressured it, preheated, turned on carefully, the lamp would start but there were flames above the ceramic nozzle area. Opened slowly the pressure release and stream coming from the crack of the Preston loop became evident.
     
  24. MYN

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    Yes. That solves the mystery:).
    I've experienced a similar scenario on one of my Petromaxes. Only thing was I noticed the very tiny flame at the leak point early. I had to braze it to make it useable as I had no spares at hand during that time.
     
  25. Adrian Romania

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    How did you go about brazing it? It's unlikely that the solder could penetrate trough suck a tiny crack that only opens up when the loop is heated up.
     

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