Removing vaporizer tube Primus 71

Hej everybody,

a time ago I found a Primus 71 from the 30ies in good shape. Unfortunately the wick seems to be bad. So I tried to remove the vaporizer tube, but it has no hexagonal nut!
I already tried heat and quench, freezing the tube and filling the tank with boiling water and also the prescall method with the wooden brackets and the g-clamp. The only thing I achieved is twisting the tube... So the material is weakened... The tube I could not remove!



Does anyone have further ideas what I could try?

Ciao, Bastian

 

I have the same problem. Well, I broke it so now it is only the threded part in the tank that is left to remove...

 

I also thought about cutting the tube, removing the lower part and solder a new thread from a younger Primus 71 (with hexagonal nut). But first I will try removing without destroying.

Ciao, Bastian

 

Shelf queen!
Duane

 

@Sternenlicht

Unless you want to do a major restoration of that burner, I think your only solution will be to replace it altogether. New burners are available from Fogas.

If that is the path you choose, you will need to remove the “screwed-in” part of the burner, probably using (very carefully) an “easy-out”.

In this post (below) I repaired a twisted, broken burner. The thread also has a link to another repair by @presscall.

https://classiccampstoves.com/threads/rebuilding-a-radius-no-42-burner.36072/

Cheers

Tony

 

Bastian:

I might suggest a final effort to save the existing stem. Pad the stem with a rag, and / or use a woodworkers vice and clamp the stem in the vise. Grip the tank / font and turn it. It may come loose, or you may twist the stem to it's breaking point. Before trying this, fill the priming dish with penetrating oil and leave it for a day or more. Then try the 'twist the tank' method.

Paul

 

@Sternenlicht
Tank base joint and fuel filler riser are brazed on the Primus and can stand a fair amount of heat from a blowtorch. Purge the tank of fuel with soapy water and expect the wick to burn.

Direct the heat at the base of the burner stem and on cooling it’s likely to have broken the bond between the burner and tank threads.

John

 

Hej Bastian,
Re "first I will try removing without destroying", I wish you well.
Thanks for posting.

I want to ADD consideration of presence of old thread sealant? Do I recall reading on CCS that heating first helps on that front?
Here is post re dissolving thread sealant, credit sa3spd.
That or "...soak it with penetrating oil or a mixture of 1:1 acetone and automatic transmission fluid" credit Tony Press.

Seeing yours twisted... i hate when that happens.
You tried freeze method, now heat is under discussion.
I comment that I remain in the camp of: freeze the rizer and fill tank with hot/boiling water (you tried that.. if at 1st you don't succeed…".
Re: freezing rizer here is one I commented on, credit Trojandog.

Maybe we learn something here.
ONE: is timing of when to apply torque a factor? I suggest you want to be setup to apply torque swiftly just after adding water, idea being at the moment female vs male threads (hot vs cold) are most effected by drastic temp change that may be the moment threads are as loose as they'll get? To hesitate might result with threads that are not as loose?

John, who speaks from far more experience than i, may agree (or maybe not?) with his "...on cooling it’s likely to have broken the bond between the burner and tank threads". @presscall

Not sure it's fair to say "wood block fix" failed. There is just no getting around too much torque was applied, the threaded portion was still "stuck!" and myself, not sure how best that is avoided. To your credit you stopped when it twisted (vs the so many that are broken off).
TWO: A worthy effort may be to develop another method for these fragile vaporizers, one that grasps the stem just above tank? Tricky. [or refine / improve freeze or other method(s) and do so w/the wood block?]
The older more fragile vaporizers, like yours, are much more of a challenge. I have a couple, penetrant alone did not work and I've set them aside.
thx , I can catch up later, omc
tag @Sternenlicht

PS tretrop re yours and "Well, I broke it..." sorry to hear of that as well. The brassies are sooo unforgiving, certainly including these fragile vaporizers!

 

If there is not thread sealant present I'd try soaking the joint in penetrating oil for about a week. My preferred oil is 50/50 acetone and automatic transmission fluid. If there is sealant on the threads, then heat.

 

Thank you all for all the helpful comments!
But I already cut the vaporizer below the first bulge (from tank to top), preventing the complete destroying of the vaporizer tube.
Now I would like to braze a stick or a pipe in the remaining part, but in the first run the temperatur was not high enough.

Soldering was not strong enough.
But before removing the remaining part I will consider your hints to break the bonds between tank and burner threads.

Ciao, Bastian

 

@Sternenlicht

Good luck.

Cheers

Tony

 

I got it out!
because also my further experiments with brazing a pip into the pipe haven't been successful I tried something different:





The inner pip is made from a nail, preventing the crushing of the pipe. The outer sheet prevents scratching and is made of an old rain gutter made of zinc. It worked!

Ciao, Bastian

 

@Sternenlicht
A result! Well done Bastian.

John

 

Great, able to repair the pieces now?
Duane

 

Thanks!
I'm thinking about brazing a butt joint or using an inner pipe.
But first I have to look for a new torch...

Ciao, Bastian

 

So, the next step is done. My new torch arrived and I silbrazed a butt joint.
It worked well. It continues...

Ciao, Bastian

 

Nice job. I wish I could get my torch to heat parts enough to melt silver solder.
Duane

 

@Sternenlicht
Nice work Bastian.

John

 

The last work is done, it's burning!
I cleaned it not too much, because of preserving the old and used character. I like, if you see the stove are use pretty well.

@hikerduane
I bought the Lötkoffer Turbo 2000 by CFH, not the best quality, but a large set for a nice price. It's fired with propane. But the parts I silbrazed should not be larger, it needed much time to reach the right temperature.
The lower pipe of the burner (within the tank) is only soldered, as it was originally.

Thanks all for all the nice and helpful comments!

Ciao, Bastian

 

Bravo @Sternenlicht