Zinc

Jewelry Discussion
1

I’m making a jewelry project in zinc (a round box containing several
bracelets). Does anybody know what’s the best way to solder zinc,
and what kind of solder to use? Thanks in advance, Linda

2

Linda zinc is often used in making pipes for pipe organs. The pipes
I have worked with have all been soldered with a lead/tin solder.
Considering that the metal point is 419.5 C, around 787 F, it cannot
be hard soldered. Bevel the edges of the joint to increase the
surface area for the solder. Hope this helps.

Bill

3 
    I'm making a jewelry project in zinc (a round box containing
several bracelets). Does anybody know what's the best way to solder
zinc, and what kind of solder to use? --

G’day; Zinc has a fairly low melting point, so silver solders
cannot be used. It is however, easy to solder with a good quality
tin/lead based solder and a soldering iron with a fairly large
copper bit, and the joint should be of the overlap type. Thoroughly
clean the two surfaces to be joined and ‘tin’. In this process, the
business end of the bit is cleaned and fluxed. There are several
fluxes. one is what used to be called ‘killed spirits of salt’ which
means that pieces of zinc were dissolved in hydrochloric acid until
it could dissolve no more, thus providing acidified zinc chloride
which is a really excellent flux. Another flux in common use was
‘sal ammoniac’ which is ammonium chloride - it is the chloride part
of these two fluxes which does the oxide removal from the metals to
be soldered. Another flux is resin based and a very good variety of
this is Fry’s Fluxite, which should be found in most hardware DIY
shops. This a brown grease-like material which is of the consistency
of vaseline. This flux is by the way, the best for electrical work.
The best solder to use is one with a high tin content, which has a
higher melting point and is stronger than other lead tin solders.
Get the ‘iron’ hot enough to melt solder when touched to it, then
flux the iron. Flux the joints and apply molten solder to them with
the iron. If the surfaces are thoroughly cleaned and fluxed, the
solder will flow very easily when the iron is hot enough. This
preliminary process is called ‘tinning’. Hold the tinned surfaces
together, (you can use a screwdriver to press the joints together)
and use the iron to melt them together slowly. When soldering the
bottom to the sides, it is possible to make a good joint without
overlap, using plenty of solder, which is slightly gap filling - but
only slightly: the bottom should fit as closely as possible to the
sides. When finished, wash thoroughly with hot water, a brush and a
little detergent. Best of all, find someone experienced in ‘soft’
soldering and ask them to show you how it’s done. The slogan for soft
soldering is; “Spend 5 minutes cleaning and 1 minute soldering!”

Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ

4

In the USA you can find rosin-core solder in places like Radio
Shack, or anyplace the caters to radio “hams”.

margaret

5

Good soldering tutorial John, it’s always good to get input like
this from you. A question though: Is it not possible to use a flame
(torch) to perform this soldering? One could obviously not use that
flame to provide pressure to the subject, but perhaps a steel
soldering tool? Tom

6 
Is it not possible to use a flame (torch) to perform this
soldering?

I haven’t been following this thread very closely, so I apologize if
this has already been pointed out. Zinc melts and vaporizes at a
relatively low temperature… much lower than most non-ferrous metals
we normally work with under a torch. The vapors are toxic. Zinc
poisoning, from inhaling the fumes, is not a pleasant thing. This is
also important to know if you ever heat anything made of galvanized
steel, which is coated in zinc to prevent rust and corrosion.

Be careful!
Dave

Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com
http://www.CarolinaArtisans.com