I picked up an Optimus 96 pretty cheaply and am looking forwards to getting it going properly but a couple of things … Firstly, the lipstick and the ‘bell’ don’t seem to want to separate - is it ok to heat and quench? Or will that cause damage? Second, this is the flame I’m getting. What’s causing this? Is it too rich? This is the first lipstick burner I’ve had so I’m learning… I’ve replaced seals and pricked the hole and the gauze inside the burner is intact and seems solid. Any ideas? And also roughly how old? I read the dating guide on here and guessed c.1962 based on the Primus spreader and other fittings. Thanks in advance C
Together with the replacement of seals, removing the gauze and unrolling it to remove dirt and carbon by means of a vinegar or citric acid soak and use of a fine brass wire brush is worthwhile - your “seems solid” suggests you’ve yet to do that. Thoroughly clean gauze prevents those deposits finding their way into the jet orifice, where pricking can provide temporary respite but since it just pushes the grit back in (and with more deposits to come) can become too regular a problem. Yes, the burn looks rich, suggesting an enlarged jet orifice. To be sure, you’ll need at least a 0.32mm jet pricker. If it passes through the jet, it congirms the hole’s enlarged and the stove won’t work properly, typically losing vapourisation at some point after the initial priming. If that pricker doesn’t enter the jet, you’ll need the correct sized (0.23mm) pricker and a good clean of the jet might restore a wholly-blue burn. Removing the burner bell from the vapouriser can be a struggle. I usually manage by using rigger’s leather gloves to grip stove tank and bell (burner on the stove) twisting the bell clockwise. Sometimes the fitting boss on a vapouriser is soft soldered, so applying heat to the assembly will potentially disrupt the joint. Besides, it’s not a procedure that’s guaranteed to work. John
Good advice from John, above. Sometimes separating the burner head from the vapouriser is extremely difficult. I now have a couple that I have left joined because of the risk of damaging the “lipstick”. See here for a very tough example. Tony
Whatever you do I would not put a tool or one of the stove legs through the burner bell holes and try to use that as a tool. The bell is not super delicate but will warp if the bell is really stuck. Leather glove and I lock the other end of the lipstick in my vise and using both hands try to turn it. No heat at all. Dont be tempted to use a strap wrench or pliers as they exude more force than just your hands. If you cant take it apart with your hands then i would leave it...use it...and try again later and see if under normal use they come apart when you try with your hands. You can try boiling the entire two parts in citric acid for a few minutes to break the carbon crap off. After if you get them apart try cleaning up both ends. They will expand and retract under normal use from the heat and get stuck again, but if the parts are clean the come apart much easier the next time.
Gauze duly removed and more penetrating fluid sprayed down the lipstick / bell join from below. Daft question I’m sure but in terms of pricker size do they have the measurements stamped on them somewhere. I have many prickers - most old - but would rather not enlarge an orifice unnecessarily Also note on the burner some suspicious marks where it looks like the previous owner also tried to separate the two C
None I’ve encountered. A micrometer’s a useful tool to have. It’s revealed to me that there’s a variation between prickers - the odd thou over or undersized. It’s unlikely you’ll be able to make larger a jet with an over-sized pricker. The pricker wire’s liable to bend first. Wear of a jet is the inevitable result of hours of creating a restriction to the flow of pressurised hot gas and maybe OCD use of a pricker. Mainly, your prickers could be a selection of 0.32mm and 0.23mm sizes, or you may be unlucky and they’re all one size (most likely 0.32mm) or the other. You might even have a really slender one (0.18mm) to prick a paraffin pre-heater or butane jet. Even without a micrometer to confirm, the appearance of the pricker wire’s a good clue as well as how flexible the pricker wire is in comparison and should identify which of the two main sizes they’re for.
Thank you @presscall I think I’ve found a .23 one … interestingly post cleaning of gauze and repacking the flame looks like this… it’s certainly not the flare stack of earlier C
Might want to look into "peening a lipstick" posts that others have done to bring jets back to life, or Prescall's hypodermic needle fix works well.
@Automedon That doesn’t look too bad. Persevere pricking the jet and whack in more pressure. The most effective jet pricking is done when the stove’s fired up. You’ve to have a good eye to quickly prick the jet without vapourising the pricker wire and the flame’s liable to extinguish (the paraffin vapour gushing out when you withdraw the pricker needle - relight immediately - ) but the pressurised gas is more likely to eject the debris inhibiting a clean burn than if pricking the jet prior to firing.
What is it's date code? The Primus 96 I have has built in ring keeping the bell from settling on to the lip stick to firmly. The Primus 100 has the bell sticking. The 100 doesn't have a ring like yours. It's from 1924. My primus 96 is from 1939. The Primus 100 seems to have an steel lipstick. the Primus 96 does not. So what did about the sticking was heating up the bell over another stove and that seperarted the bell from the lipstick. After I researched how to remove a stuck bell. But every time I fired it up it wood stick again. Two different metals with different expansion and contraction?
I always manage to loosen the bell on an Optimus 96 which sticks just by heating using meths as per the usual pre-heat before lighting. It then comes off fairly easily when holding with a rag and a gentle twist. It probably depends on the relative diameters of various lipsticks and various bells being slightly different. It then sticks again with the next time the stove is lit, so I just leave the bell attached normally and it fits in the tin like that anyway.
Hello @Automedon . If you want to take the burner bell off - Secure the burner assembly vertically in a vice. Get a spanner that just fits around the vapouriser then place it between the spirit dish and the bottom of the burner bell. Tap the spanner upwards with a small hammer until the burner bell breaks free(if it does). Appling heat first to the burner bell helps to release it(sometimes ). If it doesen't come appart, leave it as others suggest.
Thank you all… I did give it a go yesterday by securing the nut at the base in a vise then preheating as normal using meths. Alas no joy. I definitely want to separate though as it’ll be annoying if the vapouriser is kaput and takes the bell with it thereby writing off two parts not just one. Also can anyone suggest a good place for replacement supports … this one came with them all missing sadly best, Chris
you can get pot supports in england from Basecamp UK (google it for number and email) Mike will set you up with anything you need.
Another technique is to remove the bell/head immediately after shutting the stove down, using the end of the spinner or pot support if not too hot. If you got the bell off previously, you may have to repeat after each use. Duane
This might crack the brass. Best to heat, not quench. No idea what previous owner did, or how long since it was last used.
