Early Radius 12 and the infinite sadness

Hi all,

just received a beautiful early Radius 12, perfect frame, no rust, no dents, complete burners, but... cracked tanks... now what to do? Soldering? Tank sealant? Leave it alone?

Any suggestion is welcome.

Nicola

 

Additionally, I have not pressurized the tanks so not sure if they leaks but I bet so, the cracks are quite evident...

 

@Nicola Francesco Elia Stu over on Classic Pressure Lamps outlined HERE a method I recommend.

John

 

Hi John,

I know that post and once I tried on a broken stove that technique, obviously with a different (not so clean) result, but I was learning. I am not a master at soldering, also if stove by stove I am getting better understanding that preparation is the 99% of the job.

In any case I don’t feel confident enough so I will make some other tests on a broken stove to understand if would be reasonable to put my hands on this gem

Anyway I am for the soldering repair too, so John many thanks for your opinion... if only I had your skills!

Nicola

 

Any idea what would cause cracks like that? Repairing it won't do much good unless you can stop it from happening again.

Ben

 

Hi Ben,

I think age, this stove is at least 80-90 years old and it doesn’t look to be used that much.

I have seen many cracks, these looks “rigid”, the brass seems very hard... I don’t know how to explain the feel I have when I look at them, so probably it’s a production defect... would be interesting to know if they appear last week or 70 years ago Who knows...

 

On both tanks the cracks go straight following those feet, on one tank there is a second smaller crack on one side.

I bet 1$ that they appeared after a flat impact on those feet...

 

Poor annealing prior to drawing those deep forms during their manufacture created stress lines that developed into cracks when pressurised and depressurised over several cycles in use.

There’s every justification to repair the cracks in the way Stu outlined - a small hole drilled at the end of each crack; v-groove between; solder fill.

The key here is that the fuel is kerosene, so if the worst case scenario z1ulike suggests were to happen of more cracks ‘lying in wait’ (in reality, they’ve all probably already emerged) no disaster could arise as could happen with gasoline.

 

I agree with you John, I will try the repair with solder, Stubwork is inspiring.

Many thanks,

Nicola

 

@presscall Thanks for the explanation. Good luck with the repair @Nicola Francesco Elia. If you pull it off it will be well worth the effort.

Ben

 

Here in the US, I'd be using a copper/phosphorus brazing rod, melts at a rather low tempreture, and best of all, needs NO FLUX!!!

https://www.amazon.com/Bernzomatic-...ocphy=9018829&hvtargid=pla-597718548924&psc=1

Murph

 

Hi Murph,

thanks for the hint, how low is the temperature needed? I see those are brazing rods so I guess they need higher temp compared to soft solder. Am I right?

 

@Nicola Francesco Elia , the temperature is higher, 1310 - 1475 F ( 710 - 800 C ), but the lack of need for flux is a big plus. These rods are specially made for joining copper, brass and bronze, that's half the battle done before the first shot's fired, IMO.

Murph

 

Hi Murph, I get your point... I hope to find something similar at least in Europe, in any case ai want to try these rods.

Thanks

 

Thanks for that.

 

@snwcmpr , I'll drop the other shoe, mask off the crack and use milk of magnesia brushed on either side, and acts as a braze mask, keeps the brazing metal from flowing all over Sod's back acres!

Murph

 

Forum;

I agree with John about the cause: Stress crack due to cumulative fatigue and poorly annealed. I also agree with stop-drilling and soldering (referenced in lantern forum), but even if soldered by an expert solderer, I don't think solder just across the crack only will be a long-term solution because it is in tension plus cycled every use and pressure cycle, so I doubt it will stand up to the repetitive fatigue to which it will be subjected. I would recommend stop drilling, and a patch which straddles the fracture (something like 3/8" wide strap should do it)...not pretty, but will most assuredly survive long-term!

Just for example...I have successfully repaired a weeping (threaded brass water pipe, due to what looked like a grain of contamination) by soldering a copper patch over the damaged area. I cleaned the brass pipe to shiny, fitted a custom formed copper patch, and permanently soldered it in place with a MAP gas torch...I don't think MAP gas will be necessary for a stove tank repair, because the area is only thin sheet metal. ...and this past summer, I repaired numerous pinholes in a motorcycle tank due to corrosion from condensed moisture...this was relatively simple as the tank was being painted when done, so the repair did not have to be pretty because it remained visible...the technique was to file the area to clean metal, then dimple the area, then fill the area with solder (resulting in a repair area akin to a countersunk hole with a solder plug), bodywork, etc...but there is no pressure involved here. Maybe this can give some useful ideas.

Cheers

 

An update:

I finished soldering the tanks, obviously it wasn’t possible to make a chirurgical and fancy repair because there was a lot of metal tension on the cracks so once heated they “opened up” requiring more tension release with more holes and obviously more solder to cover a wider area to increase the strength of the repair.

Clearly I am not an expert about soldering, I would say a newbie, but the repair should work and last. I don’t pretend that this stove will support heavy usage, but at least it can be used from time to time to make a coffee

I will add photos when I finish but I attach a photo of the crack enlarged by the tension after some heat was applied:

 

Bravo! @Nicola Francesco Elia