| 配方类型： |
METALS AND THEIR TREATMENT |
| 配方说明： |
Noncaking Soldering-Flux Paste |
| 配制方法： |
When using a flux in paste form for soldering, brazing, or welding, the paste can be made by mixing the salts with a little water.
Especially with boric acid or borax containing mixtures, such a paste afterward leaves a hard, glassy crust on the work which is very difficult to remove and causes corrosion of the metal. A paste can also be made by mixing the salts with petrolatum jelly, using a little water as an emulsifier, but it is not so easy to get a smoothly emulsified paste in this manner. It is easier to make a paste of the powder with liquid paraffin.
However, a condition for a good fluxing action is that the paste forms a smooth, uninterrupted layer when being spread on the work without streaky smears that leave part of the surface uncovered. It is impossible to get a smooth covering effect when the powder is not fine enough. By grinding the salts to an impalpable powder so that no separate particles can be felt when rubbing it between the fingers, a paste can be made easily with liquid para |
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