Optimus 930 300CP Questions

I've just picked up a rather nice Optimus 930 300CP for £10 so feeling rather pleased with myself, but only having had Bialaddins and Tilleys in the past I think I may need a bit of hand holding here!

I know exactly what the lamp is as it's printed all over the tank so no prizes for identifying it, but what about dates?

Also is there anything specific to these lamps that I need to look out for when getting it going that I wouldn't need to on a Tilley/Bialaddin?

Are they easy to get running?

What mantles do I use that are easily available in the UK?



Finally, as you may be able to see from the picture the original globe is sadly cracked from to to bottom. OK for display but I wouldn't want to risk running it with that. So, is there a suitable replacement globe that is available in the UK that I can use for running it?

 

Coleman Globe 550 will fit

 

I use 250cp Optimus mantles with good success.

In comparison to Tilley/Bialaddin the air gap is critical. On my 930 there is no adjusting mechanism so there is a washer fitted above the nozzle to raise the J-tube a little to allow a better air / fuel mixture.

 

Congratualations on the 930. I think they are a nice reliable lamp that works well.

As for dating the lamp. The design of yours didn't change from about 1960 to the end of the 70's, so take your pick.

As for running it. They use the same principles as any 'Petromax' style lamp. I would check the jet that is fited. They might say 300cp on the tank but I find they work best with a 250cp jet together with a 300cp mantle.

I don't know about in the UK, but glass should be available. Either with or without the logo. Otherwise the smaller Coleman bulge glass (i.e. for a 200 etc.) fits, if that is easier to find.

Looking forward to seeing it lit.

 

As far as I know the 300 c.p. version is basically the same as ordinary 930 but I guess the marketing guys have been involved when they did the “upgrade”. I run both my 930 with 250 jets and 250 mantles but have also tried 350 mantles without seen any major difference. As mentioned earlier the air gap is critical and don’t be surprised if the tank become warm. That’s common for the 930.

 

My jet is marked Optimus Sweden 200... so would that be a 200CP jet by any chance?

 

Yes that's correct. It should work well. The actual burner dimmensions on the 930 are the same as on the Optimus 200 lanterns, so no problems. I have always thought the 200's give a bit more then just 200cp.

 

Yes, I agree.
A well working Optimus 200 seems to give out more light than most 300 specified lanterns.
But these things are always subjective, of course, and never an exact science.

 

I've breifly had it running with no glass or mantle and all looked good... I may need a new washer for the filler cap but the one currently fitted is holding out for the time being.

One other question though...

Does the mantle tie onto the ceramic burner itself just above the ridge or does it tie onto the metal flange just above where the ceramic burner screws in?

 

The mantle ties onto the ceramic part just as you described.

 

These lamps are curious. They seem to function well with a jet of any size from 200 to 350cp. However I had one here on Wednesday because the owner could not get it to burn right. Clean generator with good pricker and new 250cp jet and a black mantle. Odd so we swapped the burner top with one of mine and it worked perfectly. So a problem with the J tube but what? The air gap is fixed so all that remains is the tube itself. I cleaned out the tube by heating and quenching and then brushed it out and when we tried the lamp it was much improved. It improved further when I lifted the burner slightly so increasing the air gap does help. I did notice the J tube had a slight flat where someone in the past may have held it with pliers so I suggested perhaps pushing that flat out with a 12mm rod might help and perhaps a second heat-quench and brush out will also make for a smoother inner surface. It seems the condition of the J tube is critical on these. ::Neil::

 

Mine ran fine the first time I used it but developed black-mantle the next time, using the same tank of fuel.

So I think the phase of the Moon is involved somehow and also what colour underpants you have on that particular day...

 

Thanks for the info...

Pleased to say the little lamp cleaned up quite nicely.

 

It looks much better now!

Will you be lighting it? Jeff.

 

I need to get some mantles and a globe but eventually yes...

 

My 930 has a 200 CP jet. I use Optimus #4a mantles from Base Camp. I believe these are a bit bigger than the 200/250 mantles.

This compact lantern is extremely bright with these mantles and has never given me any problems (knock on wood). It's one of my favorites, and I'm sure will be for you. It cleaned up really nicely.

As mentioned, the tank gets VERY hot during operation. But I consider this sort of a feature as I never have to add additional air, the additional heat causing the pressure to increase in the tank.

Dan

 

It lives!!



Aside from the cracked globe there are two other issues:

The preheater cup leaks so you have to be pretty quick otherwise you lose all the spirit. I'm not quite sure how to fix this.

The other is that I need a new washer for the filler cap. Is it the same as used on Optimus stoves?

Other than that I had it running a fair while with no issues and it is BRIGHT!

 

Nice!
Fantastic light for a lantern this small, don't you think?

Yes the filler cap uses the same washer as the camping stoves, e.g. No. 8 and 111.
You can use the entire cap from one of those if you just need a quick fix.
Most Primus lantern caps is also the same.

Too bad with the leaking spirit cup! Is it from rust?
Where does it leak? It's the one with another piece spot welded into the bottom, right? I have one that has a tiny hole under one of the two little "feet", but without leaking.
If it's not totally rusted, you could probably carefully weld it tight with e.g. a MIG.

 

I did a little experiment with regard to the brightness which I'll post in another thread..

The leak seems to be somewhere near the spot weld that holds the shield like piece in place. It's hard to tell but it seeps out from under the little spirit bowl. I did wonder if a drop of solder would seal it.

 

It's the same place I mention on one of mine, even if mine doesn't leak.
I'm not sure solder will do. Not If you are thinking about soft solder. It can get pretty hot down there, but hey! It's worth a try.
Otherwise you perhaps could drill a little hole where the pin hole is and just simply screw a very small fine threaded screw in it. That usually is enough to seal a small hole in a thin sheet metal like this.

 

That's a good light!

 

The spot weld of the pre-heat cup seems to be a weak spot on these lamps. On one of mine the cup is loose, without leaking, and it’s some shaking to do every time every time I want to ignite it. Any good ideas how to attach the cup? Is soldering the only solution?

 

Looks good! Sadly my lamp is the one Neil refers to above. It's still not burning right even after gently de bumping the J tube. Next stop will have to be a new tube. It's strange because both at Neil's and at home it works better (although not great) for maybe the first 10 minutes, then starts to run really really over rich and blacken the mantle :-(

Regards,

Paul

 

You could probably drill and put a small screw through as was suggested for mine....

I haven't tried yet so you could go first if you like

 

Yes, I suggested that, and it turns out that I just aswell might try it out myself.

I dug out another 930, and as it happens, it got the same problem. A little pinhole just where the spot weld used to attach it to the bottom plate of the globe cage.

Here's the underside of the cup, with the hole clearly visible. It didn't leak any alcohol to speak of, but it did of course seep a little:



The inside of the cup. The spot weld is directly under (or probably also through) the small "feet" of the vertical shield:



And here is a little dimple visible where it used to attach at the bottom plate of the globe cage:


I will drill a tiny hole through all three parts, and then just simply screw a tiny stainless sheet metal screw through it all.
Or perhaps I'll go for a small M3 screw with a nut instead. I've not decided yet.

 

You forgot "to be continued..."

I'm waiting with great excitement for the next episode

 

Then you won't have to wait more.
I tried it directly after I mentioned it earlier tonight.
It took less than ten minutes. A very quick fix. And a fix it was because it worked very well.

 

Did you use one or two screws? Any washers? This is not an uncommon occurence.

 

I've now done mine too with a slightly modified procedure...

I used M2.5 countersunk screws and in a preemptive strike did both sides. Before fixing the cup to the frame I rapped a small length of soft solder around each of the screws in the hope that once done up they would form a sort of lead washer sandwiched between the cup and the frame and help seal any leaks.

I screwed the whole thing to the frame with two M2.5 nuts on the underside and did them up very tightly.

 

I only used one since it only was one that leaked. To just hold the cup, it's of course enough.
I also intend to swap the sheet metal screw for a screw with a nut. It will make it much easier to tighten all together good. I will use M3 as I mentioned before.
Some sort of washer is probably a good idea.
Like the soft solder Gneiss suggest. It will form nicely, and as long as it don't have a too low melting point, I figure it should work well.