Fast Tracks own Track Building Soldering flux is what we recommend for soldering trackwork in Fast Tracks assembly fixtures.
This type of flux ensures that surfaces are thoroughly clean and ready for soldering, making it easy for even the novice craftsman to get great results. Only the smallest amount of solder paste is needed, so a single can of paste will be more than enough to build hundreds of feet trackwork and switches.
Easy cleanup with water, will not corrode or turn green over time.
Fast Tracks track building acid based soldering flux is only suitable for soldering trackwork. Do not use this flux for soldering electrical connections or electronic components. Be sure to thoroughly clean the track using a stiff wire brush and warm water after soldering to remove all traces of flux.
Download the MSDS for Fast Tracks Track Building Flux
Before using this product, we highly recommend that you watch the Soldering Trackwork Using Acid Based Flux video for important tips and techniques.