I Just finnished restoring this Primus 1020 from 1933 with new gaskets, jet and needle. The lamp ignites and burnes, but im not really happy with the result. It is like the gases are burning outside the glow mantle, lika a "halo". Im using a "Veritas Mantle Model 3890 3/400c.p s.t". The lamp should put out more light, the light intensity is a bit low. Should i test another mantle type, or could i have done something wrong when restoring the lamp?
The symptoms would indicate it is getting too much fuel, pointing to a worn jet. You say you have changed this so another option could be a blockage in the air tube. Btw, the mantle should be fine for this lantern. I have experienced a batch of Luxor mantles, which are normally good, giving a decidedly yellow light.
On one of mine I found that I had not screwed the new jet in deep enough to seal between the top of the vapouriser and the shoulder of the jet. It had felt tight enough when I fitted it, but could screw in half a turn more when I checked it later. Since then I've started using a small lick of copper bearing grease on the screw threads and turning the jet in and out a bit so that it turns easily before finally tightening down. Less torque on the screw thread and more pressure on the sealing surface.
I tried re tightening the jet and some other parts, and at first it did burn nicely, but after a while it started "burning" again. I have restored two other lampos of the same model, that work very good. This one is slightly older so its possible that i have missed something.
I had this exact problem with an Optimus 930. Cured it by cleaning out the vapouriser loop using a flared out old bicycle cable in an electric drill. Terry
The 1020 doesn't have a preston loop but making sure the vaporiser is clear of any carbon build up is always worth doing.
The carb was indeed full och carbon build up on the walls of the tube. I still have the same problem though, burning nicely in the beginning and after 10min its burning outside the mantle.
If everything is clean with no restrictions in the air tube and the jet is seated without leaking then it sounds like you need a new jet. ::Neil::
I tried changing the jet, but all the jets i tried give the same result. The lamp does burn nicely with the rinse needle inserted though.
Yes. Or possibly a blocked/restricted air tube, but considering that this was the problem with , I assume that was the first you checked on this one.
I wonder whether a bigger mantle closer to the gen tube would help here? It may be a stupid idea but suppose it's not getting enough feedback, the vapouriser is hot after preheating and it gets some heat from the mantle but not enough. It's going to slowly cool down. I just wonder if after 10mins what the jet is emitting is not just vapour, it's vapour and atomised fuel. A bit like a Coleman white gas lamp does when starting up. It would be very interesting to run this without the globe - in still air otherwise it will cool even more. When it starts to play up wave the flame from a cook's blowlamp over the Vap tube to see what happens. If its stays the same nothing has been lost. If it improves it was too cold.
I tried JonD's advice, using a Petromax 500cp mantle instead, and the problem disappeared. My other lamps that did run OK on the old mantles did actually run a lot better on the Petromax 500cp, no flickering or burning outside the mantle at all. I guess it is possible that i got a bad batch of mantles. The question is what the drawback is from using an oversized mantle, loss of light intensity?
Compared the light beside my Petromax 500, and the Primus 1020 light is far less intense, and alot more into the red/yellow part of the spectra.
My first response on seeing the pic above would be low pressure. I take it the pump NRV seal and fuel cap seal are good? If the fount pressure is good, have you checked how much fuel comes from the fount through the vapouriser with and without the jet (outdoors)? And you are sure it is a 1020 kerosene jet and needle and no restrictor fitted on the air intake? There is not much that goes wrong with those lanterns.
It does look to be running a bit rich. Is it stable now and will it run like that indefinitely? I don't know these. Is there a Utube at the top and can the spacing be varied to adjust mixture like a Petromax I wonder? That did the trick for mine - it's an absolute powerhouse of a lantern now. Too bright for most situations. Later - had a look in the gallery where there is a 1020 burner disassembled thanks to Christer. Looks like mixture is fixed. A restrictor in the air tube as suggested above or some other obstruction seems most likely then.
The lamp is very stable, it burns that way until it runs out of fuel or pressure. I changed all the gaskets, there is no leaks and there is enough pressure. I guess it is possible that i got the wrong jets from the supplier, but i tried using the old ones and all of them had the same results.
If it is stable now it would tend to indicate that the vaporiser wasn't getting enough heat from the mantle. Of course a 500cp mantle is too big and will not fill properly giving a yellow light. Maybe the batch of Veritas mantles you have are suspect in some way (bad storage, humidity, who knows). Have you used the Veritas mantles on anything else?
I have used them on other lamps, with similar problems. I just put an order for 200-300cp mantles from Luxor, i will give them a try.
This might seem like a dumb solution but how many time are you pumping the lamp? I have a 1020 circa 1935 and I had a similar problem. After the usual cleaning, replacing parts, etc, I tried less pressure in the tank. With a full tank of kero I pumped it about 18 times. It worked great, no more burning outside the mantle. I have two 1020 lanterns 1935 and 1955 and they both gave me the same problem so now I pump them slowly and I never exceed 18 pumps. They both work great. This model seems to be a low pressure lantern. This is worth trying, won't cost anything.
I would expect them to be too small. They are the right size for an Optimus 200 etc. The Luxor 300-400cp mantles would be the right size for the 1020. Luckily I still have a good supply of Optimus 350cp mantles which work well.
Have The issue been solved? I think i have the same problem. Have a 1020. After rebuild with new jet i works really well, very bright and stable. But after 10 minuter it starts going rich with flames out of the glownet. I have identified the problem to leaks between the jet and the vapouriser. I tried put a soft copper washer betwen the jet and vaporiser, and it works for about 10 mins before the leak reappers. I have retightend this about 5 times, but it always start leaking again
Yes, no change, still leaks. I think the heat cycling with different thermal expasions loosens the jet when copper is used. I have now removed the copper washer and planning to use some exhaust cement/paste (avgaslagningspasta in swedish) to the uppger parts of the threads and base of the jets sealing surface. I think i have some ever so slightly scratched or warped sealing surfaces. But i managed to break the needle, so i have to fix that first...
Welcome @mrxxxsweden Triple X of Sweden? The copper grease or antiseize is quite tolerant to heat cycling. It should still provide enough sealing on the threads of the jet/vaporizer if enough is applied. I have experienced similar issues when lighting up a Primus. It lighted up ok after a spirit preheat but the heat from the mantle could not sustain the vaporization of the fuel. The lantern began sooting up the mantle and other parts with yellow flames a short while after light up. You might be able to find a spare needle from Fogas Sweden.
I have had success sealing leaking nipple threads by wrapping a woven strand of fiberglass in the thread and smearing it with copper or nickel grease. avgaslagningspasta could make the joint permanent? @mrxxxsweden
Tank you all for your inputs. The leaking was only part of the problem it seems. I finally seem to have corrected the leak. I tried silver soldering and then grinding the mating surface on the vapourizer än then use a freshly softened copper washer. I have now no sign of any leaks. It got a bit leaner, but after 5mins burning, it got back to rich yellow flames. But IF I dont put on the top i was ok, and after puttning top on again during operation i went rich after a few minuters. Lift the top again and it will lean out after a few minuters. Same if I ran without the glass. I also switched some parts with my other 1020 and came to the conclusion that it is the mixing tube (the U-bent tube) that has some dents in it, and when that gets really hot it starts to go rich for some reason. I have tried to insulate the mixing tube, ait tube and bottom plate with aluminium foil to make the piping and mixing air as cool as possible, but it seems to make no major diffrence (the aluminium on the mixing tube melts). I will now try with mixing in some isopropyl alkohol in the fuel to lean it out a bit, I have had some success mixing in E85, but i think i have some problems with too great diffrence in boiling points an then som separation of the etanol. I hope the IPA will solve this
You are probably getting an internal burning in the J-tube(U-bent) mixing tube. With the hood, it might get very hot after a short while and the fuel-air mixture had tended to burn internally in the tube. The j-tube will turn red hot and the mantle eventually dims. Are you able to check and verify if what I mentioned here is correct?
