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Salvage dried solder paste in tube?


#1

Hi,

I was trying to use some silver solder paste that came from Rio
Grande, delivered via a large plastic syringe.

However, it’s all dried up in a lump which cannot be removed without
cutting open the syringe. Don’t blame me, it was a gift from someone
else :slight_smile:

That said, how can I salvage this as solder? Do I take the plunger
out and put in some solvent such as water or alcohol? Or do I just
remove the solder, hit it hard with a propane torch to melt it into a
charcoal recess, and then roll it into sheet solder?

Thanks,
Andrew Jonathan Fine


#2
  1. Remove plunger

  2. dig out 3 small pieces of the solder

  3. Use plastic bottletops and put one piece in some water another in
    alcohol.

  4. hit the 3rd piece with a torch.

Which ever works the best go with it.


#3

Andrew. I had some paste solder that had gotten all hard. Mine was
in a jar. I ground up with some batterns self pickling flux, and it
works beautifully now. As your is in a syringe, I would suggest that
you get it out of the syringe, and grind it with some liquid flux,
then put it in a tight container—perhaps one of those plastic
containers that pills come in. Hope this works for you. Alma


#4

Remove the plunger and carefully remove the congealed mess with
whatever tools happen to be appropriate. I found wooden cocktail
sticks work reasonably well, you can poke through the nozzle end
after removing the needle.

Once the solder is removed, put it on a flat plate (glass is fine),
add one or two drops of pure turpentine (NOT turps substitute) and
mix/knead it with the blade of a small knife, adding turps as
required, until it’s the required consistency. Put it back in the
syringe and it works fine.

Don’t worry if the turps ignites when you heat it with a flame - it
does no harm and lasts only a second or so.

Regards, Gary Wooding


#5

Ted,

Good ideas! I love the sharing of good ideas so often seen on Orchid.

Best, MA


#6

if dried may not work at all. TRY chipping off a 1/16th in. piece
and adding ONE drop of mineral spirit let it penetrate as much as
possible ( wait after dropping it directly onto the chip about 20
minutes) then with a wooden toothpick mix. if it reconstitutes you
can try it with the rest of the contents. However, it will probably
not work because the particles of solder will have settled in the
flux. Call the vendor and ask their opinion - of course they will
recommend buying a new tube, but they are pretty helpful to novices
and may tell you tossing it is truly the best bet.

If you were to melt it down and try using the alloy, you will only
be able to reheat it once, provided you didn’t overheat it when
trying to melt it into a stick/sheet/etc. sounds like more trouble
than it’s worth not knowing how much remains and how long it’s been
dried out. I would personally burn off the flux and toss it in the
scrap bin headed for the refinery.


#7

Mineral oil. Add a few drops at the nozzle and recap. Store with
nozzle up so gravity can pull the oil down. You may have to do it a
few times. Hopefully there is just a bit of hard stuff. Don’t rush
it. Good luck! Solder paste is very thick even when new, but a firm
smooth push should distribute it. I use it directly from the tube,
not one of the tiny tips. I sometimes dotit on the area with a pin.

Kay Cummins


#8

Hi,

what I did was use a T-pin to poke a long hole in the dried up mess.
Then I put in mineral oil, and let it stand for a few days. It was
fine after that.

Cynthia Eid
Cynthiaeid.com


#9

I was surprised to hear folks are suggesting to introduce mineral
oil into hardened paste solder to renew it—doesn’t it inhibit the
flux or the solder? I ask because we all always make sure our work
is free of all grease/oils before fluxing and soldering, no…

Janet in Jerusalem


#10

Hi Janet,

I was surprised to hear folks are suggesting to introduce mineral
oil into hardened paste solder to renew it---doesn't it inhibit
the flux or the solder? I ask because we all always make sure our
work is free of all grease/oils before fluxing and soldering,
no..... 

I’ve mixed mineral spirits with dried/hardened paste solder on
several occasions with good results.

I placed the remixed solder back in the original syringe & it worked
fine. Ive remixed both silver & gold paste solder.

Dave


#11
I was surprised to hear folks are suggesting to introduce mineral
oil into hardened paste solder to renew it- 

Absolutely! Its mineral spirits that should be being recommended.
like I did. rer


#12
I was surprised to hear folks are suggesting to introduce mineral
oil into hardened paste solder to renew it 

yes, it is surprising, but that is what works! I checked my notes
several places to be sure, before I tried it.

Cynthia Eid
Cynthiaeid.com


#13
I was surprised to hear folks are suggesting to introduce mineral
oil into hardened paste solder to renew it 

Yes mineral oil is the liquid in oil based solder paste. Mineral
spirits as some have suggested will evaporate rapidly and leave you
back where you were with dried out solder paste.

James Binnion
James Binnion Metal Arts


#14

Well, now we have lots of folks confirming that adding mineral oil
to hardened paste solder renews it… but I was kind of hoping that
one of our ‘chemists’ could explain why this particular sort of
oiliness/greasiness does not interfere with soldering (since an oily
piece of metal repels flux)…

Janet in Jerusalem


#15
Yes mineral oil is the liquid in oil based solder paste. Mineral
spirits as some have suggested will evaporate rapidly and leave
you back where you were with dried out solder paste. 

Just an aside, today I sold some solder paste to a customer, and he
imparted some wisdom.

He keeps his solder past in the refrigerator, and doesn’t use the
metal nozzles, just puts a bit on his finger.

An interesting preventative. he also keeps his cold set rubbers in
the fridge too.

Regards Charles A.


#16

According to Hoover and Strong’s website this is the, perhaps
largest solder supplier in the USA, this is what THEY have to say:
Paste Solder

Supplied in 1 DWT Syringe. Excellent for chain repair. Does not
require additional fluxing. Shelf life of 6 months. We recommend that
you store paste solder in a refrigerator or in a cool place. Put the
needle end in water at the end of the day.

To soften: Use only mineral spirits, one drop at a time. Using too
much will cause the paste to fall apart.

  1. Remove the plunger with pliers.

  2. Add a drop of mineral spirits.

  3. Stir with a piece of wire or paperclip vigorously.

  4. Repeat steps 2 & 3 until the desired consistency is acquired.

  5. To replace the plunger. place an opened paperclip in the needle
    tube.

Put the plunger in all the way and pull the paperclip out. The air
will be released as you are pushing the plunger in.

Syringe = 1 DWT packages


#17
Yes mineral oil is the liquid in oil based solder paste. Mineral
spirits as some have suggested will evaporate rapidly and leave
you back where you were with dried out solder paste. 

Yes, but this doesn’t answer the (my) question…:-)… Say you’re
soldering with e. g., liquid/cone/etc. flux and wire/sheet solder.
Wouldn’t the presence of any oil in the area screw up the soldering?
If so, what is it about the mineral oil in the paste that makes it
OK?

Janet in Jerusalem


#18
Say you're soldering with e. g., liquid/cone/etc. flux and
wire/sheet solder. Wouldn't the presence of any oil in the area
screw up the soldering? If so, what is it about the mineral oil in
the paste that makes it OK? 

Quick answer: soldering temperatures are so high that mineral oil
burns off long before the solder has to melt and wet the base metal

Dick D.


#19

Heavy mineral oil or light?

Light is used in bath oil; the only use I know for heavy was my
grandmother taking a spoonful every night to

keep her ‘moving’.

j

Esta Jo Schifter
shiftingmetal.com


#20
Light is used in bath oil; the only use I know for heavy was my
grandmother taking a spoonful every night to keep her 'moving'. 

I use mineral oil in the shop to lubricate moving jewelry parts that
stick. Usually it’s something that has come out of the sonic and
been steamed and it’s so clean that it sticks, like an omega earring
back or a clasp. Just a little dot ofmineral oil will lubricate it,
it’s nice because odorless and colorless.

Be warned that it can be a little embarrassing to buy. I remember
going to buy a bottle of mineral oil at a big, crowded pharmacy. I
asked the check-out person where they kept the mineral oil and she
shouted, “Hey Jimmy, isn’t the mineral oil with the LAXATIVES. Yeah,
with the laxatives in aisle seven!” I quietly said, that I’m using
it at work, but I’m sure that just confused things.

Mark