Optimus 930 300CP Questions

Yes very odd. The black mantle syndrome is well known for most other Optimus models. I have had similar results from nearly all types but until this one never from a 930. There is nothing wrong with your lamp. Everything is clean in good condition, correctly installed and working as it should but still the black mantle. Baffles me and I am not easily defeated. ::Neil::

 

I've also had Black Mantle Disease with a 930 (and reported it here). Worked fine one night but BMD the next, even with the same tank of fuel...

 

Could it be the mantle itself?...

 

I don't believe so. I have previously run it without mantle and glass and the flames are very orangey.

It seems to be a mixture issue. If you increase the airgap by lifting the lid a little or blow into the gap then the mantle glows better and flames are a bit bluer.

Regards,

Paul

 

It's very odd given that manufacturing tolerances won't be huge how some lamps just work whilst others play up..

 

wd40addict, why not try it with a 200cp jet?
That's what many people recommend to use on the Optimus 930, even if I never had any problems with the 250cp myself.

 

I can't help but wonder if it is the quality of kerosene available in the UK. The majority of BMD occurences in Optimus lamps seem to come from there.

 

Hmmm - could be either that we run the lamps at too high a pressure (the only time [so far] I have had BMD is from increasing the pressure too fast with insufficient priming) or the paraffin in the UK is containing too much water?

I don't know - but with the Bartoline Premium paraffin we get over here I haven't (yet) had BMD under normal usage.

 

Not too much water - to all intents and purposes, kero should contain none.

Modern UK kerosene is just less volatile than it was when 'our' lamps were produced and I think that's the nub of it. Adding 10% panel wipe / Coleman etc. restores the original volatility.

This worked for my Coleman 427K Mountie the other day...

 

David, Kero can absorb water. Aviation fuel in particular needs to be tested regularly for moisture content. Although alkanes are hydrophobic, they can form "cages" around water molecules. Too much water will affect the combustible properties of the paraffin. Unfortunately, I can't remember how much water can be absorbed though. Adding panel wipe should help break up the "cages" IIRC (as will adding ethanol and decanting). It also makes it easier to vapourise as you so correctly say!

Quick Q - do most of you in the UK use long-stored paraffin or new? Where do you get your paraffin from?

I can only get it over here in plastic 4l containers and it appears to be good quality stuff - although as soon as I get to run an Optimus lantern I'll let you know if it holds up or whether it gets the dreaded BMD!

 

Me too Nils. I have been thinking the same for a long time.
I seldom have any problems like this with these kind of lamps, but it has of course happened (it has with other types too).
But it has practically always helped with a new jet and the usual service things.

 

In my case the Paraffin comes from a proper pump at a BP garage. It works fine in my Tilleys, Bialaddins & Petromax.

Regards,

Paul

 

I know it can - that's why I said "should"...

There's no reason why modern kero should contain more water than the stuff that was supplied half a century ago. There would have been none present at the end of the fractionation process and, as far as I'm aware, nobody adds it deliberately. So it gets there during storage - it follows the better it's stored, the less water will be absorbed.

To answer your quick question, I've used kero that must be decades old in lamps. Occasionally I've received lanterns containing blue and pink kero from the 50s, 60s and 70s and after a quick continence check, lit them straight up using the original fuel - just to see if they work or not, and they usually do. Even after changing seals etc., the old fuel, once allowed to settle, can be decanted straight back into the tank and burned. That's with proper lanterns, mind, not this foreign stuff...

 

David - beg pardon, I got an incorrect impression from your post.

I totally agree with you - there shouldn't be although I understand that what is rejected for use for the military is passed on to consumers so may be it's a storage thing? I just can't see them using a different fraction for "Kerosine" than 10 - 20 years ago (they may well be but I no longer have any contacts in that sphere to say yea/nay!).

"To answer your quick question, I've used kero that must be decades old in lamps. Occasionally I've received lanterns containing blue and pink kero from the 50s, 60s and 70s and after a quick continence check, lit them straight up using the original fuel - just to see if they work or not, and they usually do. Even after changing seals etc., the old fuel, once allowed to settle, can be decanted straight back into the tank and burned. That's with proper lanterns, mind, not this foreign stuff... "

That's interesting as I've received lamps with old paraffin in them (through the post no less!!!) and it is a different colour - clearer.

 

No problem - I'll add a bit of emphasis to the word 'should' in my earlier post.

I think it's a commonly held view that the volatility of kero has gradually declined over the decades. I suspect that's not so much to do with changes in fractionation (although it could be) but rather blending increasing amounts of less volatile fractions into what is sold as kero nowadays. I'm an old cynic but I'd dare bet a pound to a penny that's due to cost-saving/profit increasing by the oil companies...

 

When you put it that way, I wouldn't put it past them to say a few pence...

Aren't there two grades of paraffin now though? Agricultural & Premium?

 

Dunno, I get mine from a nearby allotment society so I guess it's 'horticultural'

 

The parafinproducts does not have a standard. The parafinproducts quality depends a lot of the source and various products containing long carbon-chains and short carbonchains is sold simply as Parafin. The chains is named C- and then a number which tells if its a long or short chain. Parafin is ment to be between certain carbonchain-numbers, but the abillity of flamecatching between these numbers is large-ish.
If technological development changes - so does the parafin. Earlier parafin contain a lot of additives to prevent the parafin from changing and from ex. absorb water. These additives is under restrictions nowadays and this has also an effect on the parafin.
Parafin of today is ment to be used within a shorter period than back in the good old days.
I could imagine if the english parafin-eating heatingsystems changes to more robust burners with preheatingsystem and highpressure injections and stuff, then the parafin-producers will correct their parafin so it becomes poorer, but that is just my imagination.
As I remember is Christer working with excactly development of stuff like this, correct me if i am wrong, so he might be able to tell more about these spekulations the companies does.
Some lamps just wont run on some fuels and it often pays to shift the fuel to something else or do as David does - ad some totally other fuel as gasoline ex.

Claus C

 

Not the cheapest way to buy it by a long shot but I always buy Pre-Pac which comes in either "standard" or "premium". I buy the standard and so far no issues... As the containers are sealed I should imagine the shelf life unopened is virtually infinite so long as it doesn't freeze...

 

Even once opened, I reckon as long as you put the top straight back on, there won't be much problem with moisture from the air getting into the fuel.

Kero is generally hydrophobic but as has been said, may absorb small amounts of water. I don't think really enough to cause a problem with burning in lamps although the military seem to take a different view, understandably. Larger amounts sink to the bottom and don't cause a problem for me. I decant it off if there's any but there rarely is.

I suspect that any large fuel tank contains a small amount of liquid water at the bottom...

 

I suspect there are differences between old and modern fuels. Some lamps are tollerant of these differences and some are certainly not. I have some 1960s - 1970s Coleman lamps that will not run on normal kero but have to have at least 10% naphtha added. It may well be the case that the problems with BMD in some Optimus lamps can be cured by adding some panel wipe or similar. ::Neil::

 

I think the difference could be more than just old and new fuel. There is quite likely a difference between countries as well. Probably more exactly, the difference is between the refineries supplying the fuel.

 

I think you're probably correct and it may well vary between the oil companies, too...

 

Maybe someone could come up with a standard "lamplighters mix"...

Would a drop of Aspen 4 work in place of panel wipe and how safe/risky is this practice?

 

Aspen, or any other alkylate petrol, will work exactly the same as panel wipe mixed in paraffin.

Incidentally, I was down to the marina yesterday and bought 15 litres of Aspen.
It is not too much more expensive compared to car petrol when you buy it from a pump on a station. Just as a tip.

 

I'm not sure you can in the UK though...

I get mine in 5l bottles from an agricultural supplier. It's not too bad as I only use it in my miners safety lamp, 150ml at a time so it lasts for ages.

Maybe if I was adding it to paraffin I might have to think again about a new source.

Incidentally, I ran my little lamp for over three hours last night with no problems other than it seems to fade a bit when a breeze hits it...

The top of the tank does get quite hot but the lower half was just warm to my touch. I assume they may run hotter indoors but then they are essentially outdoor lamps.

 

Perhaps you're right about Aspen in pumps over there.
Alcylate petrol seems to be big mainly in Sweden, and after all the particular one we discuss here (Aspen) is a Swedish brand.
But still... they have expanded widely, and is well established in Europe by now, so I would be surprised if it not was available in pumps at least at some of your larger marinas.

 

Over here they just use standard marine petrol - it's dyed blue so you can't use it in cars (as the tax on it is lower)...

 

Hello,

I also I own an Optimus 930, which develops the black mantle after about 10 minutes of running. I cured the problem by running the lantern without the hood on.

I guess the lantern runs a little to warm with the hood on. Maybe somebody else can try it with their Optimus?
Regards, Mike.

 

It might be interesting if someone who has one of these lamps with black mantle disease were to try running theirs on the Pre-Pac paraffin and see if it fixes it... maybe try both the standard and the premium...

Perhaps someone could bring a "faulty" one to Ashover and maybe test it on a variety of brands?