Using a Solder Paste vs Separate Flux and Alloy
Are you trying to hand solder components? Or do you want to use a solder paste and then pass parts through an oven or another heating device? Solder pastes are a convenient mix of both flux and filler metal, but they ultimately restrict the amount of flux you can use, so Aluminum soldering pastes are not ideal for all applications. If a solder paste has a lot of flux, there is little room left for the metal powder. But if there is a higher metal load, there may not be enough flux to solder with. Aside from metal load, a solder paste will generally contain a binder to keep the flux from reacting with the metal. This will further dilute the flux’s effectiveness. This being said, Aluminum Solder Pastes are an excellent option for specific applications.
By using a flux that is separate from the alloy, you can use a stronger, more aggressive formula. You may also decide to add more flux partway through heating or feed additional filler metal in. The biggest advantage is that you have more control over the soldering. You can choose your desired viscosity, the amount of flux used, the amount of alloy used, and how the flux and alloy are added into the setup.
Your Heating Details
To perform the soldering, you can use all sorts of methods. Viable options are: oven, hot plate, torch, soldering iron, induction, or resistance soldering. The main thing to note though is that when you consider the temperature, you are talking about the temperature of the aluminum parts, not the oven temperature, not the temperature the hot plate is set to, the temperature of the parts. The minimum part temperature that the flux will work at is 180°C (~350°F). That’s when the active ingredients work their magic. On the opposite end, as it were, you need to get the aluminum up to temperature and finish the soldering within 8 minutes. After this, the flux begins to degrade and is spent.
You’ve read through all that and thought even more about what you want to do, where do you go? After taking this information into consideration, what now? Don’t worry. Superior Flux is here to help.
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