How to Make Your Own Solder Flux

Science Technology
How to Make Your Own Solder Flux
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DangPro shows you how to create your own solder flux:

Flux is a wonderful goo that makes soldering faster and easier. In previous videos we compared different types of commercial flux, but did you know it’s possible to make a simple and effective flux at home? We’ll get you started, and don’t miss the giveaway at the end of the video.

21 thoughts on “How to Make Your Own Solder Flux

  1. Greg Silver says:

    Great info!

  2. D says:

    DangPro seems to be one happy dude.

  3. Bob Marney says:

    That was so simple. One chunk of that rosin would make enough for years to come.

  4. Bill Fredette says:

    Aha! Something to do with my son’s bass bow rosin when he isn’t looking!

  5. Thomas says:

    Great tutorial… just need 1 missing ingredient- rosin!! Lol, I shudder sometimes when a guide says I need flux, and I look to the component box and have none :(

  6. caitlinsdad says:

    any way to make homemade solder paste to use with the homemade flux? Solder paste is expensive to get and has a shelf life.

  7. KentD says:

    I like this. Rosin core solder makes you use solder to get flux, but then you may have more solder than you need for a small pin. I need to make some of this! Rosin is also useful for Chladni plate bowing.

  8. Josh says:

    Wow,that was cool! i had thought of making my own flux, but I never could find the time,I think I will now though!

  9. Nick merritt says:

    That’s really cool, I wouldn’t have thought that you could make flux so easily. What kind of tree does Rosen come from? Anyway thanks for the info I will be sure to try this.

  10. MAKE | Your Comments says:

    […] the article DIY Solder Flux, user Bill Fredette writes: Aha! Something to do with my son’s bass bow rosin when he isn’t […]

  11. Travis says:

    I almost always use flux when soldering. Especially when soldering stranded wires together. The flux lets the solder flow quicker keeping the heating time to a minimum. I find that alcohol does a great job of cleaning flux off the board after soldering giving a prettier board. A little on a toothbrush works great.

    I agree with above, now if we can make our own homemade solder paste.

  12. Cheryl says:

    Ooohh wonderful info, can’t wait to try it!!

  13. Jan says:

    I read that you can use honey straight from the container as a flux as well. It’s consistency keeps it from running.

  14. Joe says:

    Great video seems very easy and simple to do

  15. Lola says:

    I’ve been on a search to find a recipe for flux to use in my jewelry making. I use primarily copper and silver. I’m wondering if this would work as well in jewelry making as it does on this circuit board. Also, what is the shelf life after mixing?

    1. Kim Wilson says:

      Lola if your hard soldering silver you use boric acid or borax fluxes or a commercial product I think rosin will burn if your torching a bezel. Use rosin for electronics and the like. Copper in non electronic applications generally uses more corrosive fluxes. I have not used copper for jewelery making just silver and just hard (silver solder that comes in 3 grades hard medium and soft) Do not confuse the hard silver with silver bearing solders ie the “soft” hard silver solder is not a soft solder. The hard silver comes in three grades (or four if you also count one for enameling) for the convince of fabrication or repair. The Melting points are slightly different to allow soldered peaces to be built up or repaired without affecting a joint already soldered. In any case the flux should be removed except for the noncorrosive (rosin) electronics flux and many remove it as well. The rosin needs a strong cleaner that has volatile ingredients. Even rosin fluxes are mixed with ingredients to cut the oxide layer to help with the solder joint (activated flux). Activated flux should be removed in electronics work. Do not use soft solder (ie non hard silver) on silver and don’t use lead bearing solder for jewelery never.

    2. ariroark says:

      for jewellery making with non -ferrous metals ( soldering gold, silver and copper ) just use borax and denatured alcohol- the centuries old tried and tested standard that also gives some degree of firescale preventative when you first warm the metal and build coats of it onto youe work piece. The rosin stuff is for electrical soldering ( breadboards, etc.) and isn’t at all appropriate for jewellery. Pripp’s is the brand name for the flux mixture of borax and alcohol mixture- so when DIY’ing it you simply mix borax (crystalline is best, 20 mule team will do) and your denatured alcohol in a glass or ceramic container without a metal lid ( glass is best, or mix it per use with a borax cone in a dish ( a glazed terra cotta saucer works well and is found in garden stores or any jewellery supply vendor for 3x the price!) using alcohol if you are going to add the firecoat prevention step or water for speed in a single hit and run operation , like connecting a jump ring to a chain end or closing rings, soldering shanks , etc.: simple one step operations using hard solder).

  16. servis laptopova says:

    I guess this kind of flux is not very good to apply for the bga rework and reballing work .

  17. servis laptopova says:

    is the rosin also used for applying on violin bow ?

  18. ASK AN EDUCATOR! – “How about doing a tutorial on the different types of solder?” « adafruit industries blog says:

    […] solder requires external application of flux and is handy when you use different flux types (like homemade) or have specific environmental […]

  19. Michael Gerlica says:

    Well done, guys! That’ll come in handy.

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My interests include writing, electronics, RPGs, scifi, hackers & hackerspaces, 3D printing, building sets & toys. @johnbaichtal

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