GB2037208A

GB2037208A - Soldering methods and materials

Info

Publication number: GB2037208A
Application number: GB7848793A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-12-15
Filing date: 1978-12-15
Publication date: 1980-07-09

Abstract

A soldering method for joining open joints or for bridging holes (e.g. in brass or copper work pieces) includes the application of granular metal together with solder and flux. The method may include applying a mix of flux and granular metal and heating and simultaneously applying solder (e.g. by blow torch or soldering iron) so that the work surface and granular metal pieces are tinned together and flow as a mass with the solder to bridge holes or gaps in the workpiece. Alternatively, the method may include the use of a composite solder stick comprising either flux and granular metal encased in solder or, as shown, tinned granular metal 9 held in solder 8 and a flux core 10. <IMAGE>

Description

SPECIFICATION Improvements in or relating to soldering methods and materials This invention relates to soldering methods and materials. It provides the means for soldering a workpiece with holes or open joints so that these are bridged and joined together in the soldering operation with the soldering materials used.

Accordingly, the invention provides a method of soldering a workpiece with holes or open joints comprising cleaning the parts to be tinned, applying a mix of flux and granular metal pieces to the workpiece at the holes or joints to be bridged, and heating and applying solder so that the workpiece and metal pieces are tinned together and the solder and granular metal flow as a mass to bridge the holes or open joints.

The invention also provides a soldering material comprising solder, a flux and granular metal particles. The metal particles may be tinned and mixed with the solder prior to forming sticks and the flux is combined, for example as a core to the solder stick.

Alternatively the metal particles may be held in suspension in the flux which may form the core inside a solder casing of a solder stick.

Short Description of the Drawings In order that the invention may readily be carried into practice, examples of the method and materials will now be described in detail, by way of example, with reference to the accompanying drawings, in which Figure 1 is a perspective view of a workpiece with holes and an open seam to be bridged; Figure 2 shows the workpiece of Figure 1 with a mix of flux and metal particles applied; Figure 3 shows the soldered workpiece of Figure 1.

and Figure 4 shows, in longitudinal cross-section, a composite solder stick.

Description of the Examples In Figures 1 to 3, in which figures the same elements are indicated by the same reference numerals, there is shown a flat workpiece 1 of a metal suitable to be soldered having an open seam 2, an elongated slot 3 and a circular hole 4 all to be filled with solder. The workpiece is first cleaned over the areas 5 which are required to be tinned.

Figure 2 shows the seam 2 and holes 3 and 4 covered with a mix of flux and granular metal particles 6. The flux is chosen to be suitable for the workpiece metal and for the soldering operation.

Suitable fluxes are the compound sold under the registered trade mark FLUXITE, or Baker's fluid or powdered resin ora mixture thereof. The metal particles may be of any metal which can be tinned and a mixture of such metals may be used if required. A particularly suitable metal is brass.

Particle size of the granules depends upon the size of gaps to be bridged. For small holes, brass filings passing a 10 to 15 thousands of an inch mesh are satisfactory, and will bridge gaps up to one-eighth inch wide. For larger gaps, a particle size up to 40 thousands of an inch mesh may be used. Within the mesh grading specified, both size and shape of the metal particles is preferably random.

Heat and solder are applied together to the areas to be soldered, either a blow torch or soldering iron being used. For brass or copper workpieces, ordinary tinman's solder is satisfactory. The cleaned area and the metal particles are tinned together and the metal particles and solder coalesce into a metallic sludge which easily flows or may be worked into the holes or seams to be bridged.

Figures 3 shows the finished workpiece with the seam 2 and holes 3 and 4 bridged by the solder and particle masses 7.

Figure 4 shows in cross section part of a stick of soldering material which may be used for an alternative one-step soldering operation. The solder stick shown comprises a cored stick, the outer part of which is made up of solder 8 with variously-sized, tinned metal particles 9 held in the solder. A core of flux 10 passes centrally through the stick.

In use, the workpiece is cleaned, as shown in Figure 1. Heat and the solder stick of Figure 4 are applied together to the workpiece. As the solder fuses, both the solder and suspended particles flow onto the workpiece and, as the workpiece is tinned due to the flux 10, flow into the seams or holes to be filled. The finished workpiece is similarly as shown in Figure 3.

Preferably the heat applied to the solder stick and workpiece should not be so intense that metal particles on the surface of the stick are vaporised, as might occur if a blow torch is applied to the solder stick and workpiece together for a time sufficient to heat the workpiece to the correct temperature. This problem can be overcome by pre-heating the workpiece before applying the solder stick, so that the stick with its lower specific heat is not subjected to a long heating period, but a better solution is to modify the solder stick of Figure 4 (in an arrange ment not illustrated) so that the metal particles 9 are held in suspension in the flux core 10 rather than in the solder casing 8. There will then be no metal particles 9 near the surface of the stick and the chance of their vaporisation is less. The flux and metal particles in suspension are in this arrangement heated by conduction through the solder case.

1. A soldering material comprising solder, a flux and granular metal particles.

2. Soldering material as claimed in Claim 1 wherein said metal particles are tinned.

3. A material as claimed in Claim 1 or Claim 2 formed as a stick, of which the core comprises said flux.

4. A material as claimed in Claim 1 formed as a stick of solder, of which the core comprises said metal particles held in suspension in said flux.

5. A material as claimed in any one of Claims 1 to 4wherein said metal particles are of random size and shape up to a maximum particle size.

6. A method of soldering a workpiece with holes

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to soldering methods and materials This invention relates to soldering methods and materials. It provides the means for soldering a workpiece with holes or open joints so that these are bridged and joined together in the soldering operation with the soldering materials used. Accordingly, the invention provides a method of soldering a workpiece with holes or open joints comprising cleaning the parts to be tinned, applying a mix of flux and granular metal pieces to the workpiece at the holes or joints to be bridged, and heating and applying solder so that the workpiece and metal pieces are tinned together and the solder and granular metal flow as a mass to bridge the holes or open joints. The invention also provides a soldering material comprising solder, a flux and granular metal particles. The metal particles may be tinned and mixed with the solder prior to forming sticks and the flux is combined, for example as a core to the solder stick. Alternatively the metal particles may be held in suspension in the flux which may form the core inside a solder casing of a solder stick. Short Description of the Drawings In order that the invention may readily be carried into practice, examples of the method and materials will now be described in detail, by way of example, with reference to the accompanying drawings, in which Figure 1 is a perspective view of a workpiece with holes and an open seam to be bridged; Figure 2 shows the workpiece of Figure 1 with a mix of flux and metal particles applied; Figure 3 shows the soldered workpiece of Figure 1. and Figure 4 shows, in longitudinal cross-section, a composite solder stick. Description of the Examples In Figures 1 to 3, in which figures the same elements are indicated by the same reference numerals, there is shown a flat workpiece 1 of a metal suitable to be soldered having an open seam 2, an elongated slot 3 and a circular hole 4 all to be filled with solder. The workpiece is first cleaned over the areas 5 which are required to be tinned. Figure 2 shows the seam 2 and holes 3 and 4 covered with a mix of flux and granular metal particles 6. The flux is chosen to be suitable for the workpiece metal and for the soldering operation. Suitable fluxes are the compound sold under the registered trade mark FLUXITE, or Baker's fluid or powdered resin ora mixture thereof. The metal particles may be of any metal which can be tinned and a mixture of such metals may be used if required. A particularly suitable metal is brass. Particle size of the granules depends upon the size of gaps to be bridged. For small holes, brass filings passing a 10 to 15 thousands of an inch mesh are satisfactory, and will bridge gaps up to one-eighth inch wide. For larger gaps, a particle size up to 40 thousands of an inch mesh may be used. Within the mesh grading specified, both size and shape of the metal particles is preferably random. Heat and solder are applied together to the areas to be soldered, either a blow torch or soldering iron being used. For brass or copper workpieces, ordinary tinman's solder is satisfactory. The cleaned area and the metal particles are tinned together and the metal particles and solder coalesce into a metallic sludge which easily flows or may be worked into the holes or seams to be bridged. Figures 3 shows the finished workpiece with the seam 2 and holes 3 and 4 bridged by the solder and particle masses 7. Figure 4 shows in cross section part of a stick of soldering material which may be used for an alternative one-step soldering operation. The solder stick shown comprises a cored stick, the outer part of which is made up of solder 8 with variously-sized, tinned metal particles 9 held in the solder. A core of flux 10 passes centrally through the stick. In use, the workpiece is cleaned, as shown in Figure 1. Heat and the solder stick of Figure 4 are applied together to the workpiece. As the solder fuses, both the solder and suspended particles flow onto the workpiece and, as the workpiece is tinned due to the flux 10, flow into the seams or holes to be filled. The finished workpiece is similarly as shown in Figure 3. Preferably the heat applied to the solder stick and workpiece should not be so intense that metal particles on the surface of the stick are vaporised, as might occur if a blow torch is applied to the solder stick and workpiece together for a time sufficient to heat the workpiece to the correct temperature. This problem can be overcome by pre-heating the workpiece before applying the solder stick, so that the stick with its lower specific heat is not subjected to a long heating period, but a better solution is to modify the solder stick of Figure 4 (in an arrange ment not illustrated) so that the metal particles 9 are held in suspension in the flux core 10 rather than in the solder casing 8. There will then be no metal particles 9 near the surface of the stick and the chance of their vaporisation is less.The flux and metal particles in suspension are in this arrangement heated by conduction through the solder case. CLAIMS

1. A soldering material comprising solder, a flux and granular metal particles.

6. A method of soldering a workpiece with holes or open joints comprising cleaning the parts to be tinned, applying a mix of flux and granular metal pieces to the workpiece at the holes or joints to be bridged, and heating and applying solder so that the workpiece and metal pieces are tinned together and the solder and granular metal flow as a mass to bridge the holes or open joints.