To save money, it is advisable to make a silver solder with your own hands, although this step is only possible for those who possess certain knowledge. You can learn how to solder with the help of various solders purchased from a retail network.
In case of uncertainty in their abilities, you can buy solder, and not make it yourself.
What is silver solder?
Pure silver is an expensive metal and is rarely used for work. Its structure is soft, so craftsmen use alloys that include copper, zinc, as well as aluminum, nickel, and cadmium.
Silver compounds with copper and zinc are highly meltable and are used as silver solder. The solder joint made in this way is very durable. Solder with a 10% amount of silver is well processed with a hammer in the rollers and is used to solder steel parts.
Solder PSR-25 is used to connect the surfaces of brass.
PSP-25 and PSP-12 solder is used to connect brass surfaces and perform particularly neat and clean soldering points. The form of making silver solder is a solid sheet that is cut to obtain strips of the required size. For work using strips with a thickness of 1.5-2 mm, and small parts are connected using strips with a width of 3 mm. Silver solder is used to fill the gaps between the seams. They withstand significant vibration loads, resistant to shock and deformation.
The composition of silver solder sets GOST, which regulates the area of its use.Back to table of contents
The chemical composition of the alloy to combine materials
Modern technological processes of soldering include the use of silver solder, which, when connecting the nodes, is suitable for stepwise soldering. Such work requires the use of an alloy that withstands a temperature of 600 ° C.
The composition of the solder includes ingredients such as 30% silver, 20% copper, 16% zinc, 33% cadmium. The alloy is very brittle and is designed for soldering materials that are not subject to vibrations. The composition with the amount of silver increased to 52% is very fluid, but it withstands loads well during the multistage stages of soldering materials.Back to table of contents
How to cook silver solder according to the old method
There are several ways to create a silver alloy, but you can master the technique perfectly only after a long practice. To produce an alloy, it is necessary to prepare 2 coins: a fifty kopeck in 1924 and a penny in 1962. You will also need to work:
It is most convenient to heat the solder on a gas burner.
- spoon (not table);
At the beginning of the work silver is melted in a spoon. A five-kopek coin is added to the resulting melt and the mixture is rolled in a spoon for better mixing. The longer the spoon rolls, the better the mixing process. But there is one major drawback: it burns out many components necessary for solder.
Then the master, who makes the alloy with his own hands, pours it into the ingus and rolls it out without annealing. The resulting solder has high quality: 10 g belong to the 900th sample.
When soldering, it is very important to prepare fresh flux, which will ensure quality work. It is necessary to carefully monitor the size of the flame in the burner: a soft, not very hot fire in the form of a broom will ensure a high-quality weld.
For work using hard solders, which contain: 80 Ag, 16 Cu, 4 Zn, 75 Ag, 22 Cu, 3 Zn. Soft solders include: 65 Ag, 20 Cu, 15 Zn.
To obtain a light silver solder used in the repair of products, it is necessary to prepare: 7 parts of silver, 2.8 - brass, 0.35 zinc. It is important to start cleaning the brass from the oxide film before starting work. To obtain 10 g of solder melt silver 999 samples. After receiving the liquid composition add brass, mix the contents in a spoon. When the composition is completely melted, add zinc, shake the spoon several times, then begin to roll the resulting composition. After its manufacture, it is necessary to cut a sheet with a scissors and weigh it on a scale. For successful work should be prepared:
- gas burner;
- mixing paddle;
Do not master the amateur without such materials as:
Pure silver is not used for solder, as it is too expensive metal.
- pure zinc;
- borax, which is added to the molten composition.
Sometimes they do not mix pure zinc: it is better to use its alloy with brass or copper. Zinc is added to the solder, wrapped in silver foil.
To make a silver solder, you can take the silver of the 96th test, burning out the 94th test. It is obtained by burning old silver products: brocade, braid, galloons.Back to table of contents
Silver Solder Melting
Melt the metals that make up the alloy in a crucible, get a silver solder. The crucible is placed in a furnace, or the components are melted using a soldering tube. Before work it is necessary to prepare equipment:
- wooden stick or iron hook;
- charcoal mixture;
- water tank.
Solder components are melted using borax. Observe the sequence of operations: first of all, refractory metals are melted, then low-melting metals are added.
Solder components are melted with borax.
To make a solder with your own hands, in the crucible, liquid metals constantly interfere with a wooden bar or iron hook. To create a higher quality solder, the whole process is divided into two stages. The crucible is pulled out of the hearth, and the metal is combined in containers with water. Fine-grained droplets are formed, which are dried and re-melted again, covering the top with brown.
After complete melting, the metal is poured into molds. Frozen tiles or bars rolled into strips, which are ground on a lathe.
Alloys consisting of metals are suitable for technical soldering of silver objects: 20% copper + 80% silver, 4% tin + 48% brass. When soldering steel with silver, they take into account the state diagram between copper and silver.Back to table of contents
Properties of middle melting alloys
Silver solder has high strength, is resistant to corrosion in aggressive media, has a low melting point, high thermal conductivity. When working, it completely fills the gap between the soldered parts and fits well on a metal surface.
When working you need to make sure that the solder completely fills the gap between the parts.
The alloy of 28.5% copper grade PSR-72 has a high ductility. While working on the creation of solder with your own hands, it should be remembered that its melting temperature with copper decreases when doping with lithium. The resulting alloy is used for soldering steel materials resistant to corrosion. To reduce the melting point of the solder, tin is added to it in an amount of from 35 to 70%. The resulting alloy allows you to solder various materials, avoiding the formation of cracks.Back to table of contents
How to make solder at home?
Carrying out melting, it is necessary to solve another problem: to ensure the reverse process - the transition of a metal from a liquid to a dense state. Silver must be melted and then cast into ingus.
The work is divided into 3 stages: preparing the spoon — smelting, adding flux, adding charge to the spoon, melting the starting material and pouring it into the ingus.
At the bottom of the spoon place a small rectangle of cardboard, on top of a larger plate, until the last part of it wraps the edges of the spoon. Then you need to compress the cardboard sheets well. Watch the shape of the bed: it must be concave.
This is a very important moment of work: when making solder with your hands in a deep dredging of a spoon, the melting process is delayed for a long time, so it needs to be dried near the hotplate.
On the jewelry scale, the charge is sorted. Master prepares materials such as:
Materials for solder are weighed on electronic scales.
- 20 g of silver scrap of the 916th test;
- scrap of the 875th test;
- 12 g of pure silver;
- metal for solder;
- gas apparatus.
Distribute the mixture to 18-20 g in separate piles. 875 scrap and silver are mixed: 6 g of trial and 42% of pure silver are used per smelting. The mixture is cleaned with a magnet, removing impurities of iron and steel.
Solder is made of silver 875 with copper in the proportion of 4: 1 (3 copper coins and 1 silver fifty dollars). They take a borax as a flux: 1 part per 10 parts of the charge. Check the burner by adjusting the height of the flame. The spoon is placed above the burner. Silver changes its color, flows to the bottom.
The ingus is placed near the flame of the burner for heating, after having been lubricated with wax. The melt should not cool and shine. It is poured into the ingus, which is well heated. They do this immediately, with confident hand movements, so that it does not cool and split into several parts. The ingus is placed under a cold stream of water. When the bar is sufficiently cooled, it is pulled out, turning the shape. Cardboard or asbestos coating is intended for 3-5 heats.
Making a solder with your own hands is a simple, but fascinating process that requires accuracy, patience and skill.