Soldering on German Silver Radiator Neck

[1913Moline]

Lots of cars in the early teens used German Silver in construction of the radiator top tanks. A friend has a car with a very very slight leak between the filler neck and the top tank. The original joint has a crack in the solder.

Any recommendations on specific flux and solder type to fix this? We dont have any parts to "experiment on", so the concern is that we dont make a small problem into a big one. This is on a teens Pierce-Arrow, so there isnt another radiator at the local junk yard.

Suggestions??

[nearchoclatetown]

Do a search on the Web. You'll find German Silver is nickel. It should be able to be silver-soldered easily. Use a low temp solder so you don't color the surounding metal.

[1937hd45]

I'd be real sure I knew what the existing solder was before trying a repair.

[1913Moline]

I would really like to find a junk radiator to try soldering this stuff. I dont think I have ever used a "low temperature" silver solder. Whenever I have used silver solder, it is an oxyacetylene job, not a propane torch. I am paranoid about pouring the heat to it and creating an unrepairable mess.

So, I look for someone that has actually done this type of repair. I have done the google.com searches and German Silver is a rather generic term for copper nickel alloys.

Has anyone out there actually put a torch to this stuff?????

German silver

Related: Metals

name for various alloys of copper, zinc, and nickel, sometimes also containing lead and tin. They were originally named for their silver-white color, but use of the term silver is now prohibited for alloys not containing that metal. German silver varies in composition, the percentage of the three elements ranging approximately as follows: copper, from 50% to 61.6%; zinc, from 19% to 17.2%; nickel, from 30% to 21.1%. The proportions are always specified in commercial alloys. German silver is extensively used because of its hardness, toughness, and resistance to corrosion for articles such as tableware (commonly silver plated), marine fittings, and plumbing fixtures. Because of its high electrical resistance it is used also in heating coils. It was discovered (early 19th cent.) by a German industrial chemist, E. A. Geitner.

[1937hd45]

Shop around on the web and see if you can find a shop in England that makes reproduction Bugatti radiators. I've seen a few and they are works of art,hopefully that shop can help you. Check out the ads on www.PreWarCar.com

[Guest stude8]

Is your plan to try this repair with the radiator in place on the car? You sound like you have enough experience to already know the answer is not an easy one.

The trick with all radiator repair is getting the corrosion and chemical residue that is in the affected area cleaned away. That always takes solvents and acids of sufficient strength to do serious cosmetic damage to any of the cosmetic surrounding surfaces. You tend to liberate all the oils and Glycols in the coolant when you apply heat that just contaminate the solder joints.

You can deal best with preparing the surrounding cosmetic surfaces by taping over and covering everything with plastic but doing it on the car is an adding complication. The silver solder fluxes are going to be pretty corrosive to deal with and like you mentioned will require Acetylene heat power to activate. I would examine the leak very close to see if it is a previous seam that has opened or simply a stress crack developed from age and vibration. A stress crack will require a backing of copper shim stock to prevent reopening. That will be a devil to work out without detaching the tank from core.

I have had experiences with old brass tanks that simply work hardened with age and had splits popping up all over, solder one and the next opens up from the expansion and contraction of the heating. I made a decision that after 70 years of service some cores and tanks are not repairable and have to be replaced with fresh metal. Look at a lot of the acorn head lamps deep drawn or spun from brass in the twenties and thirties, they all seem to develope stress cracks with age that make repair a very time consuming affair. Stude8

[Packrat]

I have soldered nickel many times, however not as a radiator. It is not much different that soldering brass, bronze, or copper, perhaps a bit more fussy about proper cleaning and fluxing. Idealy would be to completely clean the area to be soldered in whats called "pickle" a diluted acid soultion in a warm bath, after removing all old debris, coating with a standard silver solder flux, and re soldering the joint. Heres the issues the way I see it; Like someone mentioned its critical to know what the old solder is, CAN NOT silver solder over soft solder, wont work, often can soft solder over silver solder because it wont melt it at this temp, care must be taken not to get it any hotter than necessary, that whre proper pickeling (cleaning) and proper fluxing are so important, without them one just poors on the heat trying to get it to flow. Must clean the inside of the joint as well, Also, got to plan the repair so that you are not un-soldering other parts while making the repair, this calls for a plan of action, heat where and when and in what order, and solders come in different heat ranges, repairs are best made with lower temp solders, so as not to melt other parts. If it was silver soldered, than a low temp silver solder would work, or a strong soft solder. I have names of solders, pickels, and fluxes if you like. Find out whats there, if it scrapes off with a knife its likely soft solder (tin and lead) There might be a difintive test, Ill look it up if you like. You can buy nickel to practice on easily, it is not an expensive metal, but it will be clean, and thats easier than an old radiatior! Hope this helps.

Packrat