I would like to know is it possible to solder a copper fitting or brass fitting into a galvanized fitting. this would be for a air line with 135 psi pressure. thanks for your advice
Reply:Not quite sure why you want to do this.Possible yes with the right preparation and materials.. Solder joints require a tight fit. If you turned a galvanized fitting to the OD of the copper and made a socket fitting it could be silver soldered. You would have issues with dissimilar metals corrosion however. They do make special unions that are designed to connect steel pipe to copper. I've seen them but never used them. Why not just go with a threaded male to female connection? Either standard pipe or a JIC type fittings if you need to pull it apart. You would still have the issue of dissimilar metals corrosion, but it will most likely take years before you would have any problems.