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Does solder paste break down

I have asked numerous people,but have not received a conclusive answer.Does paste solder degrade thru’ time?
I have been having no luck lately with my paste solder.I haven’t used it for years(like maybe 8yrs.)
I tried going over my prep,making sure the ends fit perfectly,sanding any crap from previous,not successful soldering and making sure it’s 100% clean.
I have been trying to solder 14k ~ 1mm jumprings.Since the wire is 24g I thought an easy easy solder would work best.After the 4th try I threw in the towel.It didn’t help either.hee hee hee.
I used my #4 smith tip,small flame and the paste doesn’t even get to that metal like ball; that happens just before it flows.It just goes crusty black.What am I doing wrong,or is my solder no good now>Please wise ones help me out.Thank you for taking the time to read this everyone,

Sounds similar to when you don’t get the metal hot enough.
If you leave the lid off paste the flux can dry out and the paste becomes crumbly, 8 years likely has the same result.
I think there was a thread a while ago on how to revive paste solder. if you find it try on a small amount and see if that helps your issue.

I’m thinking a couple of things are possible. If you add water to the paste in the container, close the container and drop that into boiling water for a few minutes you stand a good chance of reviving the paste. Mix it up to a creamy consistency.
That being said, you may want to carefully clean your rings before soldering. Boiling them in a soap solution and rinse really well. Finally, use an antioxidizing solution made with a saturated solution of boric acid and denatured alcohol. Cleaning your solder doesn’t hurt either.
Back in the day, we made our own flux using a borax cone, water, and a slate to grind our own flux a little at a time. If you are soldering on a hard surface like some of the zirconium blocks or crucibles, this may make it difficult to solder as they can draw heat rather rapidly. Working with yellow gold, a better choice would be a charcoal block.

I’m sorry if my writing reads like my flux isn’t working,it works fine it’s my paste Solder that is not performing.They come in syringes so they are not open to the air.Thanks for taking the time to answer,I appreciate that.

Do a search in Orchid on

Re: Silver Paste Soldering Problems

There is a lot of good information in that thread. I don’t know how to link it and there is too much to just copy and paste here.

Neil A

I don’t know if this will help since my experience was with silver solder, but I’ve used paste in a syringe that was easily 8-10 yrs old and it worked (although I do remember having to clean out the needle beforehand LOL). Have you tried torching just a bit of the solder? And be sure you have plenty of heat. If you were worried about melting the small gauge jump rings and didn’t get it hot enough fast enough, that might have been part of the problem (although if it won’t flow at all, then perhaps there is something wrong with it…). Good luck!

Ok, Ive watched this thread and so far, its not going anywhere. you need to think this in a technical way.

  1. solder paste is minute particles of the brazing alloy,
    2.Mixed with a flux suitable to its temp range, look up the data sheet for this.
    3.This flux and the alloy will be held together with a binder, which could be one of the following,
    water, alcohol,or a hydrocarbon like WD 40.
  2. next get from its container 3 samples about match head size and place these on a glass or ceramic plate.
  3. grind each sample one at a time with a spatula to see which dissolves the paste.
  4. once you have found which it is, then add some borax powder to make a smooth paste.
  5. Put a sample of each on say a piece of brass strip and heat with your torch to get it to melt.
  6. If borax wont help in fluxing, then you need to go to a flux thats reactive, like a stainless steel grade of brazing flux. This is reactive enough to dissolve any oxide formed on the brazing alloy particles.
    Run this trial and report back the results, then if youve not got the results you wanted then well think again.

Steps 3 & 4 and 5 are incomplete. What are you using as the grist for grinding?

Morning Ron, yes you are wise to draw attention to this, I should have made it clearer tho I thought it obvious its the 3 listed in 3!! ie water, alcohol or a thin hydrocarbon, WD40, kerosene diesel fuel or even a 3in 1 oil, tho thats a bit thick.
Hope this helps.

I have lots of experience with electronics (soft) solder paste, but not much with brazing solder paste. Soft solder paste has a shelf life and I suspect brazing paste does also. Have you contacted the manufacturer of the solder paste? Have you looked at the Technical Bulletin for the paste?

On one of those old Rio / Mark Nelson / strange craft show videos that they did (I’m guessing) quite a few years ago, Mark uses some paste solder and mentions that it can be reconstituted with mineral oil. I have never done that, but I thought I’d pass along the info.

I’ve used some paste solder, though not often, but I have been using it lately to solder 20 gauge sterling jump rings to make a chain. One thing not mentioned in the original post was the flaming that happens when the binder burns off. Did that not happen or did the poster just forget to mention it?

If it didn’t flame off the binder, I would guess that it is indeed too old. (But that’s a guess – I am in no way an expert.)

Edited to add:

Here’s a link to the video mentioned above. At about the 2:05 mark, the host asks if the paste solder ever dries out, and Mark answers that it can but that it can be rehydrated with a little mineral oil.

Rio / Mark Nelson video that covers using paste solder

Re: Paste solder
Frankly I hate the stuff. I’ve tried it several times by different companies and I’ve been unhappy with the results every time.
The only paste solder I’ve ever seen work satisfactoraly was some that my old buddy Seng Au made himself for making high karat Bot chains.
If it were my dried out paste solder I’d send it to the refiner:-)
Have fun and make lots of jewelry.
Jo Haemer

1 Like

Hi smohalia,
I can’t speak to gold solder paste but I have some Argentium Sterling Solder Paste that I use ‘very infrequently’ and was concerned about it hardening up in the syringe. I asked RioGrande and was told that I could put a drop or so of Mineral Oil [I used Baby Oil that I bought from the Dollar Store] and put a drop in both ends [the syringe end, and the tip end, and it’s kept it creamy.
If your paste solder is ‘toast’ and you want to soften it, you might give that a try…what do you have to lose!!! When I use it, I don’t notice any problem because of the mineral/baby oil. It works normally.
Good Luck,
Carol Minnich
Toronto, Ont. Canada

Since we are always careful to clean any sign of grease from parts before soldering, how is it that the mineral oil doesn’t interfere?

I use paste solder all the time and one thing I’ve found is if you use a fire coat like cupronil it can interfere with getting the solder to flow. I coat the whole piece except right at the joint were the solder is placed. I also keep my syringes in a plastic airtight container when not in use and it can last for years.

Try contacting Beth Katz in Coral Springs FL. She makes her own brand of paste solder and might be able to help.