Soldering tip melts

[tooki]

- I use Burnley soldering paste. It states on the package containing zinc chloride

That's a very aggressive acid flux, and is only suitable for plumbing and sheet metalwork.   

 I did not know the brand but searching online shows they make soldering paste for electronics so it depends on what he got.

I did a bit of deeper searching earlier, and despite it saying “made in Canada” on it, every single vendor seems to be in Asia, other than vintage tins. The manufacturer listed on the tin does exist (they are a plumbing supply company), but lists no product with that brand. So my suspicion is this:
1. That brand of plumbing flux did originally exist, in Canada.
2. It got counterfeited in Asia.
3. The manufacturer in Canada stopped making it, but the counterfeiters continue.
4. Through Chinglish translation, eBay listings for it say “pine resin” and whatnot, making you think it’s electronics flux, even though it’s not, because someone googled “flux” and just chose something.

P.S. The OP stated clearly in the original post that his flux paste contains zinc chloride.

[tooki]

Anyway, can't you order things online?

I can't for different reasons.

Well, find a way around those reasons, if your local retailer cannot procure quality supplies for you. It makes no sense to dick around with garbage solder and flux that will never produce a satisfactory result.

[Audioguru]

I use an electric temperature-controlled soldering iron with 63/37 rosin core electronics solder and the tip lasts for many years.
I use a gas torch with plumbers solder and acid flux for soldering water pipes.

[tooki]

Need to sort out terminology. I'm not entirely sure what you are referring to when you say "Paste"
Saying "paste" should always refer to 'solder paste' the stuff that looks like gray toothpaste.
If instead it's clear/yellow then it's either flux gel or liquid flux.

Mmmmm... not 100%.

1. In the past especially (and still commonly for plumbing), “soldering paste” was used to mean “paste flux [for soldering]”, and this was occasionally shortened to “solder paste”. It wasn’t until the much later invention of the solder-particles-suspended-in-flux that “solder paste” came around with the modern meaning. You can still sometimes find paste fluxes labeled “solder paste”.

2. Paste and gel flux are NOT exactly the same! Paste flux (for electronics) has historically been rosin flux dissolved in petroleum jelly, usually an amber color. (I have a tin of Kester SP-44 from the 80s, and a tube of Radio Shack paste flux from the 90s, both being rosin in petroleum jelly. The Radio Shack one is a thinner one, the Kester very, very stiff.) Modern gel fluxes, on the other hand, use solvents like glycol ethers and aromatic alcohols.

I’ll admit that there’s no clear line — fluxes exist in a fluid continuum from liquid to solid, with every viscosity in between. Nowadays, we often say “gel” for runnier pastes, and “paste” for thicker pastes. Kester doesn’t even bother — they just call them “tacky” fluxes.


3. Fluxes, whether liquid, gel, or paste, can be clear, yellow, or dark amber — or any shade in between.

Paste = solder paste, a mix of flux and tiny balls of solder used for soldering surface mount parts with hot air
Flux = a clear/yellow liquid or gel that you can add to joints to help improve soldering
Solder = A metal wire that melts under 450C/842F and has  flux embedded inside it. It comes in two main categories, acid core solder for plumbing and electrical solder for electronics

No. Solder is the alloy. “Flux core solder wire” is what you described here.

[soldar]

  I did a bit of deeper searching earlier, and despite it saying “made in Canada” on it, every single vendor seems to be in Asia, other than vintage tins. The manufacturer listed on the tin does exist (they are a plumbing supply company), but lists no product with that brand. So my suspicion is this:
1. That brand of plumbing flux did originally exist, in Canada.
2. It got counterfeited in Asia.
3. The manufacturer in Canada stopped making it, but the counterfeiters continue.
4. Through Chinglish translation, eBay listings for it say “pine resin” and whatnot, making you think it’s electronics flux, even though it’s not, because someone googled “flux” and just chose something.

P.S. The OP stated clearly in the original post that his flux paste contains zinc chloride.

Counterfeit goods on eBay? Say it ain't so! My trust in humanity is shaken!

Seriously though, good investigation.

[tooki]

Thanks! I, too, was shocked (shocked!) to discover that not everything on eBay is genuine! 

I did find an MSDS for it under the Burnley name, but it’s from 2009 and hosted on some random website, while the manufacturer’s website doesn’t list it in their MSDS list. So I suspect they retired the Burnley branded product at some point in the last decade. (They sell a different formulation under their own name, with an MSDS from 2017.)

[Mechatrommer]

Put the "Burnley soldering paste" (flux) somewhere away from electronics. Anything electronic related that it touches will be damaged, even after a single exposure. Think of it like acid, anything it touches will be eaten away.
Or return it to the shop and tell them its acid flux. If the shop is for electronics only and doesn't sell plumbing supplies then they may have ordered it by mistake

i think your statement is an exaggeration or you never used one, only from hearsay. now i dont know about Burnley brand but i've used another brand of zinc chloride flux on electronics before, i've never seen any corrosion related or component level failure so far yet. i used to single pass cleaning with normal thinner and rub with tissue. there are 2 issues that i figured out so far though, one is leakage current through adjacent traces because of few Mega ohm it created, not suitable for sensitive accuracy low current low voltage high impedance circuit. and second is high voltage breakdown, anything greater than 50V i think is a big no no, when it breaks down, it act something like a short. my no brand tip corroded in months of usage though by the neck (upper part of the tip) not right on top of the tip. so something much much more aggresive than zinc chloride must have eaten the OP's tip. but your and anybody's advice on ZnCl unsuitability for electronics is pretty much valid though, because of the said issues, ymmv.

[GreyWoolfe]

Paste is a generic term for the composition of a substance.  Solder paste is totally different from flux paste (and from toothpaste  ). 

THAT explains why I have dentures now.  Dammit.

[Ian.M]

Well, if you regularly used  Burnley acid zinc chloride paste flux on your teeth, I'm surprised you have gums left to seat your dentures on!  Do you by any chance resemble a horror movie hillbilly?      

[Brumby]

My first reaction when I saw "zinc chloride" was

As said above, it is a flux used in plumbing - and it is as old as the hills.

I was first introduced to it by my grandfather when I was just a wee lad, where it was called "killed spirits".  You could make it yourself by dropping pieces of zinc into some hydrochloric acid until the fizzing stopped.  The word "aggressive" in describing its action seems less than adequate.

Using it on anything made me feel uncomfortable, but electrical connections - definitely not!  Steer clear of it.

[Brumby]

Two other points, while I'm here...
1. Overheating.  This is where the iron it hotter than it needs to be.  This can cause several problems:
 - Greatly increased risk of damaging components, PCB tracks and wire insulation
 - Accelerated aging of the iron, especially the tip
 - Burning off the flux before it can do its job
 - Accelerated oxidation of the metals you're trying to join, if you have no effective flux
... not to mention the corrosive effect of a hot acidic flux on any metal it touches.

2. Lead free solder.  As a hobbyist, stay away from it if you can.  It's a challenge to use, especially if you are new to the skill.  Lead free is specified because of the sheer volume of products that are soldered in the commercial world.  The small amount used (by comparison) of even the most avid hobbyist, is of little consequence.

[soldar]

I am also surprised by the butane instead of electric as it must be much more expensive, complicated, inconvenient and impossible to regulate well. I would think it would only make sense if there is no access to electricity.

[Ian.M]

Actually, I used to prefer my Oryx Portasol gas iron to a Weller TCP solderstation.  It has a much shorter wrking distance between the grip annd the tip, heats up quicker, and at full flow has more power.  Although it doesn't have closed loop temperature control, with enough practice, you could regulate it well enough for most work and was quicker and easier to adjust compared to changing TCP Magnastat bits to change the temperature.   The Weller TCP only got switched on for *long* soldering sessions.  Gas was a negligible consumable cost, as regular sized cans of butane were available from the dollar store and each gave many fills.   I no longer have the Weller TCP station as maintaining the Magnastat switch in the iron was becoming increasingly difficult,  and spares for the iron were becoming ever more expensive.

Zinc chloride is hygroscopic and deliquescent, so even if you start with dry zinc chloride, it adsorbs any traces of moisture available and tends to eventually liquefy.   In solution it partially disassociates to form zinc hydroxides and hydrochloric acid.  Heating hydrated zinc chloride liberates hydrogen chloride fumes.  The only fluxes more evil than it are fluoride based brazing fluxes.

Hydrochloric acid is notorious for its fumes corroding metal surfaces, ruining precision equipment.  It can flash rust steel in minutes, and the usual advice is never store it in the same room as precision equipment unless its in a well ventilated fume cupboard.   One bottle of conc. hydrochloric acid with a stopper that isn't an absolutely perfect seal can ruin a whole workshop full of machine tools  in only a few months.

[soldar]

Actually, I used to prefer my Oryx Portasol gas iron to a Weller TCP solderstation.  It has a much shorter wrking distance between the grip annd the tip, heats up quicker, and at full flow has more power.  Although it doesn't have closed loop temperature control, with enough practice, you could regulate it well enough for most work and was quicker and easier to adjust compared to changing TCP Magnastat bits to change the temperature.   The Weller TCP only got switched on for *long* soldering sessions.  Gas was a negligible consumable cost, as regular sized cans of butane were available from the dollar store and each gave many fills.   I no longer have the Weller TCP station as maintaining the Magnastat switch in the iron was becoming increasingly difficult,  and spares for the iron were becoming ever more expensive.

I have never used a gas iron and your post makes me think I could use one on many occasions. Not infrequently I see myself walking with a hot, unplugged iron to where I need to work and then walking back to plug it in again when it cools down.

My electric irons do not have temperature control and I am quite used to working around that. If it has been a while in the holder and I need less heat I blow on it. If I just used it and I need a lot of heat I'll wait a bit. I might look into a gas iron although I guess I cannot buy them on eBay or by mail due to the gas.

[Ian.M]

Of course you can buy them mail order.  The manufacturers purge the gas after testing them.   I used to regularly fly with a Portasol iron and never had any problems with security inspections as I always vented as much gas as possible out before flying and packed a note that it had no gas in it with it.  However that did mean I always had to buy a can of gas locally on arrival.

[Brumby]

I have a couple of gas-powered irons.  They are convenient on occasions and can offer hot air and blowtorch functions as well, if you need them.  You do have to be careful about the hot air from the exhaust ports of the soldering tip, though.

I used to regularly fly with a Portasol iron and never had any problems with security inspections as I always vented as much gas as possible out before flying and packed a note that it had no gas in it with it.  However that did mean I always had to buy a can of gas locally on arrival.

That is useful.  I've never needed to take one in an aircraft, but know I know how to do it if I need to.

[Ian.M]

You do have to be careful about the hot air from the exhaust ports of the soldering tip, though.

However, its good for doing small to medium heatshrink jobs - hold the side of the portasol tip combustion chamber under the sleeving on the item to be shrunk, about a centimeter below it, and slowly turn the item, working along its length till done!   

[Brumby]

Yeah - I admit to having done that myself when I've been too lazy to change to the "hot blow" tip.