Soldering paste

Don Case

Don Case

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I'm trying to purchase the soldering paste that's been referred to a few time on here. What I'm talking about is the flux mixed with finely ground silver solder. When I asked at local shops they usually hand me a jar of flux. When I explain that it should have the solder in it I just get blank stares. If I search on the web I get a whole gamut of results most of which don't actually say what I'm buying. What should I be asking for? I prefer to use Amazon.ca so I don't have to plaster my Visa info all over the net so I'm a little shy of buying something from "Joe's Soldering Shop in West Fencepost, Iowa".
 
Don Case said:
I'm trying to purchase the soldering paste that's been referred to a few time on here. What I'm talking about is the flux mixed with finely ground silver solder. When I asked at local shops they usually hand me a jar of flux. When I explain that it should have the solder in it I just get blank stares. If I search on the web I get a whole gamut of results most of which don't actually say what I'm buying. What should I be asking for? I prefer to use Amazon.ca so I don't have to plaster my Visa info all over the net so I'm a little shy of buying something from "Joe's Soldering Shop in West Fencepost, Iowa".
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Like this?

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I use this stuff: Solder-It

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Go to the plumbing supply dept. A product called "Tinning Flux" has finely ground solder in it. Used by plumbers soldering copper fittings, it fluxes and pre tins the parts. The joint then readily accepts more solder if required to fill the joint. Oaty has several varieties, Lead free, water soluble. A 1.7 oz tin is about $3.00 and will last a lifetime.
 
"Silver soldering" is typically used when high strength joints are needed. This is not generally necessary on the scale level. Yet there is an advantage here because lead is a naughty metal to use in models due to corrosion / longevity issues. Jewelers chop silver wire into tiny pieces. They then paint the area with flux before carefully arranging the sliver slivers and applying torch heat. Search "Silver solder" on YouTube to see this in action.

Please do not use this knowledge to fashion scale models of conflict vessels. Please build models that represent joy and production, not fear and destruction. Please do not show war implements to children.
 
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I'm thinking part of the problem is here we don't seem to distinguish between flux and paste. If you say soldering paste here most people think you mean flux.
Tinning Flux sounds like something to look for but isn't tinning used more with soft solder?
 
Don Case said:
I'm thinking part of the problem is here we don't seem to distinguish between flux and paste. If you say soldering paste here most people think you mean flux.
Tinning Flux sounds like something to look for but isn't tinning used more with soft solder?
Click to expand...
What is soldering flux? Flux is a chemical cleaning agent used before and during the soldering process of electronic components onto circuit boards. ... The flux also protects the metal surfaces from re-oxidation during soldering and helps the soldering process by altering the surface tension of the molten solder.

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What is soldering paste?
Solder paste is a mixture of minute solder spheres held within a specialized form of solder flux. As the name indicates it has the texture of a paste, hence the name. The fact that it is a paste means that it can be easily applied to the board during PCB assembly. The solder particles are a mixture of solder. Traditionally this used to be tin and lead, but legislation has been introduced around the world, to only use lead-free solder. These may be made from a variety of mixtures. One is 99.7% tin and 0.3% copper, whereas other mixtures include other metals including tin.

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So...what is the difference between soldering flux and soldering paste?
Solder paste contains solder particles and flux. It helps ‘tin’ a surface with a coating of solder, resistant to oxidation.
Solder Flux is just ‘flux’, a chemical to clean the surface, ready to accept solder. Solder has to be added to make the joint or tin surface.

Hope this will clear some doubts...:cool:
 
Jimsky said:
What is soldering flux? Flux is a chemical cleaning agent used before and during the soldering process of electronic components onto circuit boards. ... The flux also protects the metal surfaces from re-oxidation during soldering and helps the soldering process by altering the surface tension of the molten solder.

View attachment 290459

What is soldering paste?
Solder paste is a mixture of minute solder spheres held within a specialized form of solder flux. As the name indicates it has the texture of a paste, hence the name. The fact that it is a paste means that it can be easily applied to the board during PCB assembly. The solder particles are a mixture of solder. Traditionally this used to be tin and lead, but legislation has been introduced around the world, to only use lead-free solder. These may be made from a variety of mixtures. One is 99.7% tin and 0.3% copper, whereas other mixtures include other metals including tin.

View attachment 290460

So...what is the difference between soldering flux and soldering paste?
Solder paste contains solder particles and flux. It helps ‘tin’ a surface with a coating of solder, resistant to oxidation.
Solder Flux is just ‘flux’, a chemical to clean the surface, ready to accept solder. Solder has to be added to make the joint or tin surface.

Hope this will clear some doubts...:cool:
Click to expand...
Note that most PCB's have their components surface mounted and are soldered on using a wav solder system....no paste involved.....
 
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Just to complicate things, I have an old can of Kester flux(what my Dad called paste). It is labelled "Acid Paste Flux". I suppose the "paste" is to distinguish it from liquid or powdered flux but I can see where Dad got it from.
 
Don Case said:
Just to complicate things, I have an old can of Kester flux(what my Dad called paste). It is labelled "Acid Paste Flux". I suppose the "paste" is to distinguish it from liquid or powdered flux but I can see where Dad got it from.
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To simplify things, Don, you absolutely CAN NOT solder parts using just flux (without solder), however, you CAN solder using just paste as it contained solder particles and flux.
 
Got it:) Actually I had it quite a while back. My dad taught me to solder 60 some years ago. Then 37 years in the telephone company. I've soldered a bit. Never heard of soldering paste (the mixture) until a couple of years back.
 
Don Case said:
Got it:) Actually I had it quite a while back. My dad taught me to solder 60 some years ago. Then 37 years in the telephone company. I've soldered a bit. Never heard of soldering paste (the mixture) until a couple of years back.
Click to expand...
I did my share of soldering too. As an installer for Western Electric, as an electrical engineer and with all the crap I built. ( TV's, radios, etc)
 
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