Hi Folks I have been asked by a friend to renovate to working order his father in law’s Primus 1020 which has a “faulty on/off knob”. Now unfortunately I do not possess any Primus lanterns so I am learning on the job and have told my friend this. The control cock spindle seems to be seized with the outer packing which is loose as received. Not knowing what to do next and not wishing to cause any (further) damage I would greatly appreciate any assistance. In case my explanation is wanting I have shown the problem here: Many thanks. Regards Jeremy
Hi there , the bottom of the push rod is flattened with what looks like rack and pinion type movement, keep turning and the rod up it should come out.
That is not an uncommon problem with old 1020s. The shaft is seized and because the cleaning needle rod uses a rack and pinion control, you can't just unscrew it. A lot of penetrating oil and gentle persuasion is needed. And patience and the odd swear word as well. Try gripping the shaft with a drill chuck then gently trying to move the block (I don't have a word for this bit) with a spanner.
@X246A Glad you brought this up Jeremy. Stripping my lantern down to get you the photos I found that the pricker tip had discarded its needle - stuck in the jet. Sufficient protruded from the jet to remove it, thankfully. Two prickers ordered (part no. P6131) from Base Camp. With a spare nipple (P6145) and half-a-dozen mantles, a goodly sum, but well worth it for a favourite lantern. John
@Darryl Durdin @Nils Stephenson @presscall Hi folks. Excellent information once again, I’ll get on to it soon and report back. Would the application of gentle heat possibly assist? John thanks for the pictorial, very useful. Regards Jeremy
You would want to be very careful with heat. It is very close to where the fittings are soldered into the tank.
Humm... Jeremy, can you work the valve knob shaft so that the pricker rod moves up, slightly pull up on the rod at the same time turning the knob shaft? I personally would not use heat, too close, as Nils said, to parts you could accidentally unsolder. I had this happen on my 1955 1020, and if you just put some oil down there where the little "rack and pinion" is located, I think it will ease right out. Just don't force it!
Hang on, it’s surely evident from the photos that when the component bearing the shaft is fully unscrewed from the tank riser, there’s nothing preventing the assembly from coming out of the riser. Once separated from the lantern it’s just a matter then of working on freeing up the control shaft in the component.
@X246A That’s how it goes sometimes Jeremy. While you’re here, did you check whether your FL6 has the gauge gubbins (float/arm) inside the tank? I’ve made another of those dials for you to install if so. John
@presscall Hi John 1) Really strange, but your suggestion works with your photograph however when I unscrew (anti-clockwise) the bearing shaft in my case it actually lowers the cleaning rod so it has at some time been assembled the opposite way round. 2) Oh bu@@er! Completely forgot to check. Will do do as soon as my chores have been completed. Regards Jeremy
It hasn't been assembled the wrong way around. That is the way it should work. You can see on the photo of the valve block (for lack of a better word) that the hole is to the right. That means that the cleaning rod goes down the left side. Makes it a pain when you have this problem.
@presscall @Nils Stephenson Sorry folks if I’m testing your patience (no to mention my comprehension) but now I’m really confused. John, I’m not able to fully unscrew the component bearing shaft because I run out of teeth on the cleaning rod and if forced any further I am likely to damage the teeth on the cog. Am I being a complete fool or am I missing the bleeding obvious? Many thanks and regards. Jeremy
’Running out of teeth’ on the rack is when it parts company with the pinion and can be removed from the tank riser.
@presscall Hi John Sorry if I’m being dense here, but when I try to unscrew the bearing shaft it lowers the cleaning rod bringing the cog teeth on to the fully circular part of it: Apologies but I seem to be lacking the words to explain myself clearly today. Does my crappy diagram help. Regards Jeremy
It’s actually a rather good diagram Jeremy. I doubt I could draw a pinion feehand so well. I see, it’s me who’s been thick. My excuse is I’ve not had the control spindle seize up on that component and couldn’t visualise it, in spite of your video. My apologies. Yes, turning the spindle forceably anti-clockwise would risk damaging pinion and/or rack teeth and maybe shear off the spindle to boot. Darn! It’s down to penetrating fluid and judgement when it’s had a chance to work as to how much torque you can apply to the spindle clockwise, freeing the pricker rack, or anti-clockwise on the hexagon flats on that spindle bearing - just enough to jam the pinion/rack teeth without damaging them. Could take a while! Cheers, John
I suppose you could fill the tank with water and position it so that the part with the fitting is under water, then apply some heat to the thread end of the shaft housing. Gently does it so you don't melt the solder on the tank fitting. Btw, that's a really good drawing.
@X246A I'm the one who's dense... I'm still not sure what's happening here. Can you turn the spindle counter-clockwise and gently pull up on the pricker rod? You could try just a small amount of powdered graphite on the rack and pinion area and see if that will free it up.
@george Took me a while to get my head round it so don’t worry yourself unduly. If you look at my diagram I need to turn the spindle clockwise to raise the needle enough to clear the toothed rack enough for it to disengage and therefore allowing removal. Unfortunately the spindle is (currently) resolutely refusing to budge in the bearing. It is only the partially loosened bearing that has limited movement. Still, tomorrow is another day... @presscall Hi John I didn’t get into my workshop today as I had to do the family food and general provisions shop today and we make this last all five of us two weeks until the next shop. As I said to George: Still, tomorrow is another day... Regards Jeremy
@X246A Hi Jeremy, I have found that a 50/50 mix of Acetone and Automatic Transmission Fluid works a treat on stubborn parts. You may already be using this mix so this is just a suggestion. Cheers, Norman
@X246A I see now. Counter-clockwise opens it up.... Checked my 1020 (1935) and its marked right on the little valve wheel. (Boy, one brainfart after another... getting serious)
@Norman Hi Norman Many thanks, that is exactly what I use, however I would always rather have someone mention something just in case I’m not aware. @george Hi George Seriously, it took me ages to get my head round it. By the way I have never heard the expression “brainfart” before and rather like it! Anyway, the good news is I finally managed to get them safely apart. Method used: Penetrating fluid as per @Norman suggested, support fount and secure pricker shaft in vice and using an adjustable wrench and after ten minutes or so the seizure finally released. Wise words from @Nils Stephenson: So now cleaned and loosely reassembled it works. So now for a couple of final questions regarding the photograph below. Do I need any form of seal at location of red indicator, or should I just use some thread lock? I assume all I need is some graphite packing at location of green indicator? Regards Jeremy
Red arrow: Originally Primus used a thin lead washer here, but later on they had stopped doing that. It is a slightly tapered fitting so it shouldn't be necessary. I usually don't bother. If there is a leak you can always look at it then. Green arrow: Yes, just your standard graphite packing.
@Nils Stephenson Hi Nils Thanks for the (hopefully) final information to enable me to have it up and running. I might just punch out a thin lead washer which may save taking it all apart again later. Kind regards, Jeremy
@X246A Great, Jeremy! Patience and good advice from Nils and Norman paid off. I had the riser in my 1001 Primus break on me, part that holds the pricker, and I never did find a replacement. A good friend of mine in Holland made a new one for me. This was years ago. I didn't want to see you break yours, although they are a little easier to find for a 1020 than a 1001 Primus.
@X246A Well done Jeremy well done indeed. I'm looking forward to seeing the money shots. Cheers, Norman
I see Nils has answered that. Mine has the thin lead washer but he’s right, the taper should make the seal. John
