Temperature at the top of the tank for Petromax 350

I got and old Petromax350 from the internet. A made in Germany one. Unfortunately it had a leak at the top of the tank on the nut that holds the female bottom for the central screw. A simple fix was to use solder to fix it and as far as the pressure is concerned the solder holds very well. We used a hard solder that should melt at about 180C. But I wonder if this lamp can be lit. Does anyone know approximately the temperature at the top of the tank when the lamp is lit?

I guess that since the lamp gets oxygen from below the frame, the temperature can not be very high since there is plenty of air circulation.

But still I hesitate to light it up. Is there any information about this? What if I add the extra protection plate?

If it is dangerous I guess I will add a .... led in it.

 

That makes it soft solder. Hard solder (silbraze alloy) melts upwards of 450 degrees C, depending on the silver content.

I’d expect the temperature of the top of the tank not to exceed the temperature of the fuel it contains.

I’d be more concerned about soft solder’s moderate shear strength and wonder what sort of mechanical stress that joint might be subjected to.

If naptha were the fuel and not kerosene I’d be more concerned still.

 

I share @presscall s view in general.
But think the solder only needed to close a hole/gap. Would not expect high load on the joint. Because the skrew ends in a steel sheet inside below the tank top.

 

Yes you are right. We did not have tools to melt the 450C solder. I should have written "the hardest we could melt". Fuel is only kerosene (never anything else). Thank you both.
So I will give it a try (outside) and use an electronic thermometer to try to see how the temperature raises there

 

Not very hot. Certainly way below 100°C for a lantern that properly functioning at full blast.
It might feel rather hot to touch if it ever gets to 70°C.
Not anywhere close to the melting point of any regular 60/40 or 50/50 soft solder.
Not really necessary to add a protection plate if the lantern's functioning properly.

 

Thank @MYN I will give it a try in the weekend. By the way this lantern has a red top, enamelled. Does anyone know a service or an enamellist in EU that could re-enamel this? I can not find anyone in Greece (searching the web). It is a small removable part (as it can be seen in the pictures I attach) that can be easily shipped.

 

A member here does that professionally I think... @Tilleyz13

 

Great, I will try to contact him. Thanks.

 

i would first check if it is an original red top Petromax. The openings in the top for metal lips confuse me.

 

And how would you do that? The tank has the regular logos and the "Made in Germany". The frame has the typical 826/350 CP super original Petromax logo. The top now does not have something written on it. The original tops (brass or plated) write Petromax but this one does not. I thought that the red enamel covered the stamp.

The nickel plated top was polished to a good shine with the petromax polishing paste. The difference can be seen in the first two pictures above. The tank did not get a so good polish as the top. Is there a trick to improve the polish of the tank and make shine as the top? Maybe a mild citric acid solution? It looks as the top before I polished it.

(No answer from Tileyz13 yet)

 

As far as I know the original red top petromax has two screws which hold the red top in place.
The top shown may be not original. Hence the "lip holes" and no lips on the red part.
The "normal" tops are crimped on and have no fasteners at all.

 

This red to DOES have lips:

 

I just do not see any logo on the red part. Is it normaly red from below too? So you say that this top is "normal" (whatever this means...) and not "original". Right?

 

This too:

has lips and not screws.

 

Well one thing is sure: there is no marking on both red tops ;-)

 

@Antonis Tsolomitis
Please show us your Petromax with all the details. I want to see how many rays the sun has on the Petromax logo. I would like to see whether the pressure vessel on your Petromax says Germany or Made in Germany.And I want to see if there is a number stamped on the bottom of the tank below.

I have a Hipolito H-201 with a red enamel cap.The red cap is also attached with 6 clips. The bottom number 2118 tells me that the Hipolito was made in 1981. But it is also possible that Hipolito bought the enamelled caps.

The video clearly shows an asian Petromax.

 

That is correct for the pre-war models. Sometimes there was also a nickel disc/plate between the screw heads and the enamel cap.
Those with the enamel cap crimped on were definitely made much later, as Reinhard explained, and as can be seen from the features. I have one of those here, too. Unfortunately it has no date stamp on the bottom. The previous owner told me that he had bought it in the 1980s from a department store in Germany.

 

@Martin K. , @Reinhard metioned the red top from a Hipolito which has similar taps.
If I remember well Radius or Optimus has them too.

Crimping was the normal procedure (?) for a Petromax after the war I guess. Lantern made by Hipolito may have the taps like shown then.
I think that crimping with a enameled top is more difficult due to the enamel not giving the right dimensions for crimping.
The big openings, shape, may also give a date indication (@Reinhard ?)

 

The lantern I have here is a stamped as a Petromax, but from the "look & feel" I guess that it was made in Portugal. This also fits with the statement of the previous owner.
I don't remember any version with an enamel cap made by Graetz in Altena, but I don't want to rule out the possibility that it existed.

 

I've seen Petromax 826s like this with a red enamel hood three times on the www The were always offered from Greece.
1102 = week 11 year 1970 Tuesday (Petromax Altena,Made in West-Germany )

 

Sure. Here are the photographsQ

 

The image that shows the Petromax tag (with the 826/350) clearly shows that the petromax paste I used although it polished the frame it did not succeed to polish the tank. The tank is full of dull spots. Is there any advice how to polish this too to a good shine ?

 

So the 4965 should mean 49 week of 1966 day 5. That is 8 December of 1966. Correct? Also notice that the base is not plated as the rest of the lantern. The base shows the brass.

 

I think it is an original Petromax 350 (Germany, typical 1960s and later). Not sure about the red enamelled cap or the outer hood though. It does have similar dimensions and shape to a Hipolito or even some of the China-made ones.
It is not uncommon that the bases came as unplated, unlike the rest of the lantern.
The nickel plating had partially worn off or corroded and is showing bare brass at the spotted areas. Further polishing will not restore it into its original full-nickel finish.
You can still make it shine up as much as possible with some gentle polishing with Autosol or similar products. Too much further polishing will thin down the nickel even further and expose more brass. It might look mirror-like initially (when freshly polished) but it would soon re-tarnish after some use.

 

@Antonis Tsolomitis
You made the Petromax very nice

The identity has been clairified .

 

Thanks for the information. It is strange that the frame and hood have been polished to a mirror like and not the tank. I would thought that the hood would be the first to have problems with tarnish and the tank the last, since the hood gets more tortured when the lantern is lit. Anyway, I will give it a try again with glanol/autosol.

 

I needed to change the gasket at the point the generator screws on the tank. I bought a viton rubber for this, removed the old "metalic" one and tried to screw the generator. The videos on youtube say that we need 8 turns. But I only succeded 7. I checked for leaks and it does not leak. However the tool that measures the distance from the nozzle to the mixing tube says that the distance for a 350 must be 1.3cm. Now it is 1.15 cm. The tube is at it's highest point.

I wonder if that is OK, or I should force the 8th turn. If yes I have to find a stronger guy that myself

 

I assume that the Petromax hoods are chrome-plated and the rest of the lamp is nickel-plated .At least at the time of manufacture in Altena.
I always use lead seals there.7 turns is enough.The correct J-tube spacing is achieved by adjusting the J-tube.

 

Be careful that you don't tear the solder on the tank fitting.

 

OK then, since I has checked that there are no leaks I will stay with the 7 turns. The J-tube though is I think on its highest position. I will double check this, but I am pretty sure I can not put it higher except if I press to lift a bit the collar that holds the J-tube above the burner.