Anchor clone pulsates heavily unless control wheel is in 10 o clock position

I ended up owning an older Anchor clone which was in a rather bad shape. After a few hours of fettling I got it to work quite nice with one exception: when the control wheel is in 6 o clock position the lamp pulsates heavily (and breathes like Darth Vader, only faster ).
This also coincides with the fount warming up a lot.

I only managed to find a workaround by fiddling with the control wheel: somewhere between 9 and 10 o clock the pulsation (and the heavy breathing) stops and the lamp works as it should.

What can cause this behavior? It's not like the lamp is unusable as it is, bu I'd rather have it work flawlessly after all the effort I put into it.

Thanks a lot for any advice.

 

It's not getting the proper mixture of fuel and air, carbon on the pricker rod can cause that, also the pricker rod is adjustable, the bottom end is threaded and there is a nut for setting the position.

 

The pricker rod is definitely adjusted correctly as the needle just barely sticks out when the control wheel is in the 12 o'clock position. The air gap is set correctly too.
Will test with another jet.

The overheating of the fount suggests that hot fuel makes it's way down when the lamp pulsates.

 

I have a hot running Anchor which is a real workhorse .. it just works perfectly every time but I've had to adjust the air gap and I suspect the jet is worn. This is ok but I'll have to replace the jet at some point and re-adjust the air gap again to compensate.

Worn jet = more fuel delivered = more air required = larger air gap on the J tube... hope that makes sense.

 

When you turn the control knob - does it go all the way round smoothly ? (no snagging or uneven resistance apart from the spring pressure) and in both directions ?

 

Thanks Colin. Have you experienced any heavy pulsation/breathing sound with your Anchor?

 

Not really smooth but it's a very slight friction on some points. I blame it on the fact that the slight bend of the rod isn't perfectly aligned with the slight bend of the upper gen (had to adjust the rod length when fettling it).

In any case , the needle comes out in the center of the upper gen and the rod has some play in all directions, as it should.

 

I have in the past but I've fitted copper wire or brass mesh round the pricker rod which increases the surface area and that usually settles the pulsing issue.

 

BTW, I've used solid copper wire from mains cables. It may not be a standard fix bit it works for me and it's readily available... I've pulled loads of old electric cables out of skips for just this purpose. Recycling at its best if you ask me!

 

In that case I really would double-check that the small pip on the end of the excentre rod is engaging in the correct place on the rod joiner. I had exactly all of these same symptoms and chased round and round until I worked this out. It is easy to get it in the wrong place while re-assembling. picture courtesy of Restoration of a PETROMAX 829 Lantern

 

I'm very sure that I put it in correctly (it engages and disengages the valve correctly and it doesn't "jump" when disengaging) but I was thinking it may have something to do with the height adjustment of the two rods. On the Anchor (and the Sea Anchor as well) both ends of the rod can be adjusted for height. This means that (within certain limits of course) you can adjust how much will the valve be opened. I understand that in theory that shouldn't matter but the fact that I can bring the control wheel to 9 o'clock and get read of the pulse/breathing sound seems to point that I'm somehow reducing the fuel flow either at the valve or with the needle.

 

Colin, where exactly did you installed the wire? I was thinking to make a coil that will just fit on the inner wall of the upper gen and install it jut below the threads of the jet. This way it can't go down as it it stopped by the constricted area of the generator and it can't go up as it encounters the jet threads.

 

Things tried this evening: installed a coil of 1mm gauge wire just under the jet and replaced the jet with a 350CP. Lamp acts exactly the same, just it's a little dimmer (as expected with 350CP) and the pulsation/breathing are less powerful when the control wheel is at 6 o'clock.
Next thing to try is a bigger air gap, the trouble being that the J tube is a bit closed so it cannot get it any higher unless I straighten it up.

 

Well... I coil it round the pricker rod and then reassemble the vaporiser/jet/Preston loop.





Here is is assembled again and working (any excuse!)

 

To be perfectly honest, now they've been fettled and properly adjusted, my Anchor 950s are my go to lantern in a powercut or if I need light where there's no power.

 

I placed a coil above the constricted area of the upper generator, just above the jet. There were no improvements. Will also try to put a coil below the constriction as in your picture the next time when I disassemble it.

However I found another workaround and that was to bump the pressure to 2.5 bar. It took care of the business, the lamp is now running smooth with the control wheel at 6 o'clock.

Like you, I am also pleased with the build quality of the older Anchor when comparing it with the more recent Sea Anchor clone. The differences aren't that big but a bit here, a bit there and suddenly the overall impression is of a far less flimsy product. Looks to me like they are made in the same factory but over the years the QC became less and less accurate and the workmanship also went down.

 

Btw, is the upper generator in your Anchor clone slightly bent towards the center of the lamp? Mine certainly is.

 

@Adrian
What you observe is called Leidenfrost-effect.
The pulsating comes from intermittend spontaneous vapourization. The ressilting gas bubbles isolate the liquid kerosene from the generator inner surface.
What you need is larger surface for more evenly warming the kerosene and vapourization.
This is by means of brass mesh or stranded copper wire coil inside the lower end of upper generator part, below the preston loop.
Ideally the wire coil or brass mesh should touch the inner surface of the generator for good heat transmission.

 

Thanks for the suggestion.

I just ran the lamp to empty and it turns out that it needed less then 4 hours to go trough 0.8 Liters of fuel. Not sure how this is even possible as it didn't smelled of partially burned fuel. Could it be that a slightly enlarged jet and a bigger air gap resulted in vastly increased fuel consumption without an orange aura?

Will test again starting with 1 liter of fuel and a brand new 350CP jet.

 

I've found that the generators on these go in all directions, maybe because of the heat and on mine I often bend them gently into the correct direction again.

 

Brass gauze stuffed in the section between the lower end of the vaporizer and the constricted part. Wrapped around the pricker rod.
That'd reduce the pulsation. The heat transfer to the fuel would be somewhat improved.
It would also reduce the volume occupied by the fuel inside the vaporizer at any time and ensure a smoother and just sufficient fuel being vaporized. In addition, it provides some resistance to backflows into the fount as the heated fuel expands.

 

Thanks, I will try to use a thicker copper wire around the rod (to try and somehow block the backflow) and will test again.

 

Reading back the first topic I think that the problems lays in the adjustment of the central rod which operates the foot valve as well as the needle.
If while pre heating the lamp breaths like dart vader the foot valve is leaking.

The valve control has two positions: close/open.
Anything between is adjustment or wrong handling.

 

Wim, the lamp doesn't behave abnormally during preheating. It does the pulsation and Darth Vader breathing when operating, if the control wheel is in 6 o clock position. But even in this situation it gives good light.

After it is heating and operating, if moving slowly the control wheel I can find a sweet spot where it no longer breathes/pulsates but operates normally giving a steady and very good light. Even after running 1-2 hours normally, if I move again the control wheel to 6 o'clock it will start to pulsate and breathe heavily again.

Sometimes (but not always) if bumping the pressure to 2.5 bar after 1 hour or so of operation, I can get to move the control wheel to 6 o'clock and still have the lamp work normally.

 

The fact that you can move the pricker control wheel to find a 'sweet spot' where it burns correctly means you are restricting fuel until it reaches the desired amount. This is pretty good evidence that the jet has become enlarged and needs changing.

 

I thought the same but I already tried 3 jets. Two were 350CP and one 500CP, it does pretty much the same thing.

 

Hmmmmm, maybe the pricker rod it set too high or too low and needs adjusting? It's worth a try.

 

The needle just comes out of the jet, enough only to catch it with the nail.

I'm thinking about testing with a different batch of fuel.

 

I had a dirty batch of fuel a while back and I still have a minor blockage now and then that requires me using the pricker on whatever lantern I'm using.

 

I moved the upper generator and the J tube assembly from the Anchor on the Sea Anchor clone and it worked flawlessly. Fuel was the same in both lamps.

At this point the only remaining suspects from a mechanical standpoint are the foot valve, the rod control assembly and the rod itself. But I'm thinking that maybe the lamp body alignment could play a part as well.