even if it costs more than other types, could anybody please suggest
a solder paste (available from Mouser or DigiKey) that works very well
solder-wise (nice to work with, good results, etc..), but that has a
long shelf time and that preferably doesn't need to be stored in a
fridge?
PS: Sorry I forgot to say that I can (and intend to) use leaded paste,
as it's for an automotive application (and of the most harsh kind, too).
I investigated solder pastes a year or so ago and all the big manufacturers that I contacted said it had to be refrigerated and had a specific shelf life -- usually around 6 months. The samples I got all came packed an in packs and were shipped overnight, so they seem pretty serious about this. But shelf life will vary based on how the temperature cycles up and down over time, and how many times you open the jar and get moisture in it. I found it interesting though that some solder paste in a syringe I got from Digikey, called "Chip-Quik" for small rework, was not refrigerated and worked quite fine -- better than the hobbyist solder pastes.
Actually, now I remember there was a hobbyist solder paste in a syringe that claimed to require no refrigeration. I never tried it, because I previously tried another hobbyist solder paste in a syringe and it was miserable. The vendor suggested the flux must've separated so I should mix it, but mixing solder in a syringe is impractical.
I've noticed that Kester solder wire works very well after 5 years, even though the shelf life is stated as 2 years. And better than "new" radio shack solder. So I'm willing to bet that solder pastes will probably last longer too, though I can't say how much longer.
I keep mine refrigerated, and if you're concerned about getting a fridge, get a small wine-cooler perhaps -- $70 new, and probably half that used.
> Hi,
>
> even if it costs more than other types, could anybody please suggest
> a solder paste (available from Mouser or DigiKey) that works very well
> solder-wise (nice to work with, good results, etc..), but that has a
> long shelf time and that preferably doesn't need to be stored in a
> fridge?
>
> PS: Sorry I forgot to say that I can (and intend to) use leaded paste,
> as it's for an automotive application (and of the most harsh kind, too).
>
> Thank You very much,
> Mario
>
> I've noticed that Kester solder wire works very well after 5 years, even
> though the shelf life is stated as 2 years. And better than "new" radio
> shack solder. So I'm willing to bet that solder pastes will probably
> last longer too, though I can't say how much longer.
I am still using the roll of Kester solder I bought 30 years ago. There is probably 1/3 or the original 1 pound left. It still works great.
> Actually, now I remember there was a hobbyist solder paste in a syringe
> that claimed to require no refrigeration. I never tried it, because I
> previously tried another hobbyist solder paste in a syringe and it was
> miserable. The vendor suggested the flux must've separated so I should
> mix it, but mixing solder in a syringe is impractical.
>
I have read somewhere that an ultrasonic cleaner could mix the syringe
quite well -- never tried though.
>
> I've noticed that Kester solder wire works very well after 5 years, even
> though the shelf life is stated as 2 years. And better than "new" radio
> shack solder. So I'm willing to bet that solder pastes will probably
> last longer too, though I can't say how much longer.
>
> I keep mine refrigerated, and if you're concerned about getting a
> fridge, get a small wine-cooler perhaps -- $70 new, and probably half
> that used.
>
> Perhaps this helps,
> -Neil.
>
>
>
> On 7/8/2012 3:00 AM, Electron wrote:
> > Hi,
> >
> > even if it costs more than other types, could anybody please suggest
> > a solder paste (available from Mouser or DigiKey) that works very well
> > solder-wise (nice to work with, good results, etc..), but that has a
> > long shelf time and that preferably doesn't need to be stored in a
> > fridge?
> >
> > PS: Sorry I forgot to say that I can (and intend to) use leaded paste,
> > as it's for an automotive application (and of the most harsh kind, too)..
> >
> > Thank You very much,
> > Mario
> >
>
>
>> ... The vendor suggested the flux must've separated so I should
>> mix it, but mixing solder in a syringe is impractical.
> I have read somewhere that an ultrasonic cleaner could mix the syringe
> quite well -- never tried though.
> Tamas
This is the sort of thing that makes a list like this (wide topic
range, freedom to wander around the central subject, large and varied
user base) invaluable. This suggestion may or may not be a good one,
as Tamas notes, but it 'opens up the mental filters' and adds to the
memory base of "things that might work and might be useful" for
recovery at some later date. Thanks.
>I investigated solder pastes a year or so ago and all the big
>manufacturers that I contacted said it had to be refrigerated and had a
>specific shelf life -- usually around 6 months. The samples I got all
>came packed an in packs and were shipped overnight, so they seem pretty
>serious about this. But shelf life will vary based on how the
>temperature cycles up and down over time, and how many times you open
>the jar and get moisture in it. I found it interesting though that some
>solder paste in a syringe I got from Digikey, called "Chip-Quik" for
>small rework, was not refrigerated and worked quite fine -- better than
>the hobbyist solder pastes.
>
>Actually, now I remember there was a hobbyist solder paste in a syringe
>that claimed to require no refrigeration. I never tried it, because I
>previously tried another hobbyist solder paste in a syringe and it was
>miserable. The vendor suggested the flux must've separated so I should
>mix it, but mixing solder in a syringe is impractical.
>
>I've noticed that Kester solder wire works very well after 5 years, even
>though the shelf life is stated as 2 years. And better than "new" radio
>shack solder. So I'm willing to bet that solder pastes will probably
>last longer too, though I can't say how much longer.
>
>I keep mine refrigerated, and if you're concerned about getting a
>fridge, get a small wine-cooler perhaps -- $70 new, and probably half
>that used.
>
>Perhaps this helps,
Yup, thanks, I will purchase the SMD291AX10 from Digikey (which seems the
one You were referring to) which declares to have all the specs that I need..
I have ordered the stencil from the same manufacturer that is making the
PCB. Now I need that thing (sorry, I don't know the name :P ) to distribute
the paste over the stencil.. can You suggest me a good one from Digikey or
just the name of the type of product, so I'll search it? I can't find any
thing neither with the name squeegee nor spatula that came to mind. Or what
I can use that I can readily find in brico shops, etc..? Maybe an exacto
knife spare blade? What to get the best results? The stencil is in alpacca.
>-Neil.
>
>
>
>On 7/8/2012 3:00 AM, Electron wrote:
>> Hi,
>>
>> even if it costs more than other types, could anybody please suggest
>> a solder paste (available from Mouser or DigiKey) that works very well
>> solder-wise (nice to work with, good results, etc..), but that has a
>> long shelf time and that preferably doesn't need to be stored in a
>> fridge?
>>
>> PS: Sorry I forgot to say that I can (and intend to) use leaded paste,
>> as it's for an automotive application (and of the most harsh kind, too).
>>
>> Thank You very much,
>> Mario
>>
>
>
>>Actually, now I remember there was a hobbyist solder paste in a syringe
>>that claimed to require no refrigeration.
All suppliers reccommend refrigeration, teh qyuestion is how long they actuall last without. I'm
told moisture is at leas as much of a proglem for lifetime. I have some EFT Solderplus paste maybe 5
years old that's still fine. You can also rejuvinate paste that is getting a little dry by adding flux
>I have ordered the stencil from the same manufacturer that is making the
>PCB. Now I need that thing (sorry, I don't know the name :P )
Squeegee
>to distribute
>the paste over the stencil.. can You suggest me a good one from Digikey or
>just the name of the type of product, so I'll search it?
Look at screen-printing suppliers. A rigid piece of stiff, thin plastic can work well, as can an offcut of a stainless stencil. metal scrapers for painting/decorating can also work as long as the edge is free from burrs
On 7/9/2012 10:08 AM, Electron wrote:
> I have ordered the stencil from the same manufacturer that is making the
> PCB. Now I need that thing (sorry, I don't know the name :P ) to distribute
> the paste over the stencil.. can You suggest me a good one from Digikey or
> just the name of the type of product, so I'll search it? I can't find any
> thing neither with the name squeegee nor spatula that came to mind. Or what
> I can use that I can readily find in brico shops, etc..? Maybe an exacto
> knife spare blade? What to get the best results? The stencil is in alpacca.
>
> Cheers,
> Mario
>
You probably mean a squeegee. I got a thin cheap crappy one with a stencil kit from stencilsunlimited and it was junk, and could not understand how to use it for this purpose. I've found that a plastic bondo-squeegee (from an auto parts store) works well, and I recently picked up a more sturdy metal (stainless steel I believe) putty knife (~4 inches wide) from a hardware store for this purpose, which I heard works well, but I haven't tried yet.
Do you mean alpacca silver? I'm not sure what a putty knife will do to that, so you can try the plastic bondo squeegee first.
The solder paste I've worked with has always required a corresponding recommended flux for it to melt and spread properly not only in the oven but through the screen so as it doesn't bleed.
Excess solder from the screen printer used to be sold to a bloke down the street who'd repackage it and sell it on to unsuspecting customers.
Regarding refrigeration, as someone else mentioned, all the
manufacturers recommend it. The big name manufacturers will actually
only ship it with some sort of cooling pack, as I understand it, in
order to keep it cool in-route. The problem is that, over time, the
flux in the solder paste will dry out. This actually will happen
regardless of whether the paste is refrigerated or not, but keeping it
cool extends the life of the paste.
For hobby use, or for use with small board quantities, buying super
expensive paste and then also having to pay super high shipping
charges for the overnight shipping (and the cooling pack) is totally
unnecessary. As the SparkFun tutorial says, it would be a disaster for
bad paste to be used on a high volume run, but when using it for only
a few boards it's not that big of a deal.
I buy my solder paste from DealExtreme: http://www.dealextreme.com/p/lodestar-soldering-paste-50g-4711. It's
$3.37 for a 50g jar, and it works great. If you haven't placed your
order from DigiKey yet, I actually have some extra unused jars on hand
and would be happy to sell one to you at the DX price.
> The solder paste I've worked with has always required a corresponding
> recommended flux for it to melt and spread properly not only in the oven
> but through the screen so as it doesn't bleed.
>
> Excess solder from the screen printer used to be sold to a bloke down the
> street who'd repackage it and sell it on to unsuspecting customers.
>
> Colin
> --
> cdb, .....colinKILLspam.....btech-online.co.uk on 11/07/2012
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