Is flux supposed to be solid?

[Somerandomtechyboi]

Bought one of these cheapo flux in a box but how the hell am i supposed to use it if its solid?

[Somerandomtechyboi]

3 minutes ago, James Evens said:

This is rosin. To convert it into flux you need glycerin and alcohol.

 

Alcohol i can buy, but i dont have any rn, ill buy today since im also buying rams for my x58 to compete in the folding comp (aka excuse to degradation test)

 

Apparently i can also just melt it with an iron but unfortunately my other iron is fked

[Poinkachu]

12 minutes ago, Somerandomtechyboi said:

Alcohol i can buy, but i dont have any rn, ill buy today since im also buying rams for my x58 to compete in the folding comp (aka excuse to degradation test)

 

Apparently i can also just melt it with an iron but unfortunately my other iron is fked

Just buy a paste / liquid flux, really.

[Somerandomtechyboi]

3 minutes ago, Poinkachu said:

Just buy a paste / liquid flux, really.

I bought 2 of these so ill have to use em ¯\_ (ツ) _/¯ 

 

Also why the hell did my solder iron just randomly emit sparks and make an explosion noise?

[mariushm]

Mix with Isopropyl alcohol , 20-40% rosin (finely chopped, granules)  to 60-80% isopropyl alcohol ... let the rosin dissolve/mix with the alcohol for a few hours, to get liquid / paste like flux.

 

Food grade glycerin is OPTIONAL, it can be bought and added you only need like a drop or two for a 100-200ml bottle. It's optional, but helps keep the flux in suspension, instead of depositing if you don't use the flux for long periods. 

 

The rosin in that solid form is used often for tinning wires .. you strip the insulation off a wire, place the wire above the rosin, then heat the wire until it goes into the rosin and now your wire has flux on it, which means you can easily put solder in a cup solder tip (solder sitting on tip for long time means the flux inside the solder wire is all gone, burned, so you have more or less pure tin/tin+lead on the solder iron tip) and then drag the solder tip across the exposed fluxed wire.

See the video at the bottom where you see how flux is used by that guy that does paranoid over the top "nasa grade" (as their manuals say you should do):

 

 

See my post in the older thread below: 

 

 

[mariushm]

1 minute ago, Somerandomtechyboi said:

 

Also why the hell did my solder iron just randomly emit sparks and make an explosion noise?

If the iron tip is not grounded, ground it... sparks can happen if the other part is powered. You can damage the part you solder on. make sure the part is not powered (unplug power supply or whatever)

 

If the iron tip temperature is too high, you'll burn the flux too fast and it will be ineffective. For motherboards, you solder iron tip should be at around 360-400 C 

 

[RollyShed]

A question, what are you soldering?

Are you using 40:60 solder which usually comes with flux in it?

 

It would be probably more than 5 decades since I used flux such as you have but have been soldering a vast array of equipment since that time.

[RollyShed]

30 minutes ago, mariushm said:

Mix with Isopropyl alcohol , 20-40% rosin (finely chopped, granules)  to 60-80% isopropyl alcohol ... ......

 

 

In the YouTube video he takes about 3-1/2 minutes to tin (put solder on it) a piece of wire.

It would take me about 10 seconds, maybe 15 seconds to do the same job.

 

The wire stripper I use is an old German one with a multitude of sprung loaded stripping teeth. You don't need to adjust them and they surround the wire and do a very clean cut of the insulation. The other cheap stripper I have has straight blades and sprung loaded so again no adjustment need for it either.

 

The solder I've always used is British and comes with flux in it.

[Somerandomtechyboi]

11 minutes ago, RollyShed said:

A question, what are you soldering?

Are you using 40:60 solder which usually comes with flux in it?

 

It would be probably more than 5 decades since I used flux such as you have but have been soldering a vast array of equipment since that time.

Bios chips for crossflashing shenanigans like ep45 ds4p to ud3p just incase i can get an improvement in oc ability by swapping bios

 

it looked liquid in pictures so i thought itd be liquid but guess not, so just 20% rosin and 80% IPA and then theres diy flux paste?

 

I do use solder that has flux in it but im trying to desolder

[mariushm]

56 minutes ago, RollyShed said:

In the YouTube video he takes about 3-1/2 minutes to tin (put solder on it) a piece of wire.

It would take me about 10 seconds, maybe 15 seconds to do the same job.

 

The wire stripper I use is an old German one with a multitude of sprung loaded stripping teeth. You don't need to adjust them and they surround the wire and do a very clean cut of the insulation. The other cheap stripper I have has straight blades and sprung loaded so again no adjustment need for it either.

 

The solder I've always used is British and comes with flux in it.

The guy takes so much time because he's demonstrating the steps as a student reads them from a standards book / manual - it's a whole process that must be followed to guarantee reliability, minimal or no impurities, it's requirements for soldering on airplanes and stuff like that. 

Of course you could do it faster, and he could do it faster - for example he stops to explain something which forces him to clean and tin the solder tip again, because according to the standards, the solder on the tip is by now oxidized and not pure enough, and you don't want to introduce oxides/dross to the wire. 

When you work and tin wires, you don't stop to chat, so you can keep tinning wire, adding more solder, tinning another wire and so on. 

 

I posted the video to show why you can't rely on the flux INSIDE the wire for some scenarios - when the solder is melted into the cup of the iron tip, the flux is burnt out, it's no longer there. That's why flux has to be added to the wire. When you form a bridge of solder between the tip and the wire, the flux on the wire starts to heat up and becomes active (acidic) and attacks the surface of the wire, removing oxidizes and crap, and now you can drag the solder and the solder will form a chemical reaction with the clean surface under the flux. 

The flux is then cleaned in the video because while the flux is more or less neutral when cooled down, no longer corroding, its presence can still affect things, and you don't want that in high reliability jobs.  

It's also a good video to show the proper way of cleaning the tip before working - lots of people just wipe dirty tip on sponge when in fact tip should be cleaned and then gently wiped on sponge as a final step to "shock" whatever remaining oxides are on tip before you apply fresh solder on the tip to prevent it from oxidizing in free air. 

I still use a paper towel or something similar to remove whatever solder I added last time I used the solder iron, then clean the tip in a brass steel wool ball and last I may slide the tip across a slightly wet sponge and then I tin it with fresh solder.

You can also see how he cuts a very small piece of solder wire from the spool, and recommends doing that because he has no way of knowing if there's FLUX in the solder wire right there at the start. If someone used solder wire by bringing it to the solder iron tip or metal to be soldered, the flux core could melt and pour out leaving with a few mm or so of solder without flux in the middle - flux melts and activates at lower temperature than the actual solder.

 

Yeah... your kind of wire stripping tool is often avoided because of the potential of cutting strands from the bundle of wires. Ideally, you use a tool with HOT thin wires to melt the insulation around the wire, allowing you to gently pull the insulation without untwisting the strands. 

 

Your solder is maybe a British BRAND but it's most likely imported or manufactured somewhere else. Fact that it's British doesn't mean anything.  

[RollyShed]

47 minutes ago, mariushm said:

to show why you can't rely on the flux INSIDE the wire for some scenarios - when the solder is melted into the cup of the iron tip, the flux is burnt out, it's no longer there.............

"to show why you can't rely on the flux INSIDE the wire for some scenarios - when the solder is melted into the cup of the iron tip,"

The flux is in the solder, not the wire. It isn't burnt out, it is all part of the soldering process. And what cup in the soldering iron? The soldering iron has a pointed tapered tip and the solder is applied to the wire via a hot iron tip.

 

"the surface of the wire, removing oxidizes and crap," - tinned copper wire protected by the insulation so where is this oxidation?

 

"lots of people just wipe dirty tip on sponge when in fact tip should be cleaned and then gently wiped on sponge as a final step to "shock" whatever remaining oxides are on tip before you apply fresh solder on the tip to prevent it from oxidizing in free air." - OK, I suppose I should in the next few years, wipe the tip of my soldering iron. I haven't used it since yesterday.

 

"You can also see how he cuts a very small piece of solder wire from the spool, and recommends doing that because he has no way of knowing if there's FLUX in the solder wire right there at the start." - Oh! I've only been picking up the reel of solder, insulated reel so I don't burn my fingers, and simply apply the end of the solder to the item to be soldered for the past 50 years. Meaning I haven't been wasting short bits of solder full of flux.

 

"your kind of wire stripping tool is often avoided because of the potential of cutting strands from the bundle of wires." - we went to that type of stripper to avoid cutting strands. It, the German one, Bernstien, is the only stripper I'd trust not to cut strands of wire. You can feel the pressure applied to the wire. You apply the pressure, not a spring loaded type. The only spring part is to allow the cutters to slightly wrap around the insulation.

 

"the flux core could melt and pour out leaving with a few mm or so of solder without flux in the middle" - most unlikely because of the diameters of the pores where the flux is and the flux viscosity. Any flux loss would be less than 1/2 mm at the very most.

[mariushm]

27 minutes ago, RollyShed said:

"to show why you can't rely on the flux INSIDE the wire for some scenarios - when the solder is melted into the cup of the iron tip,"

The flux is in the solder, not the wire. It isn't burnt out, it is all part of the soldering process. And what cup in the soldering iron? The soldering iron has a pointed tapered tip and the solder is applied to the wire via a hot iron tip.

The flux is in the SOLDER WIRE - it's either a flux core, or multiple flux cores across the length of the solder wire.  

They make the solder wire from a much bigger solder bar or tube, usually at least 15-20mm in diameter, and then that bar is extruded through smaller and smaller rollers or dies until the solder wire is reduced to 0.5mm...1.2mm in diameter, but you still have that 1-3% of flux core inside the solder wire. 

 

See https://www.farnell.com/datasheets/1866333.pdf for pictures of how solder flux is present in the wire 

 

You can multiple choices when it comes to soldering iron tips. It's not just conical or chisel, there's lots of other tips, some more suited than others. 

For drag soldering and tinning wires, there are solders with cups in the tip, to hold solder ... the surface tension of the cup keeps the solder even when you hold the soldering iron with the solder down towards the circuit board, and you can use that solder to do drag soldering (you do need separate flux to wet the leads of the surface mount chip before)

 

See shapes BCF, BCM and particularly BCM  (3rd from the right) :

 

 

So you can get solder wire and melt it into the cup of that tip, sort of like a solder pot. You're burning the flux inside the solder wire this way, so you must have flux on the actual wire for the material to be cleaned of oxides and crap and also for flux to clean oxides forming on the actual solder (because heat from iron tip accelerates oxidation) and make good chemical reaction between the solder and the wire.  

 

 

27 minutes ago, RollyShed said:

 

"the surface of the wire, removing oxidizes and crap," - tinned copper wire protected by the insulation so where is this oxidation?

You're not always dealing with freshly stripped wires. Sometimes there's already stripped wires and you can't cut the wire to smaller length. 

27 minutes ago, RollyShed said:

 

"You can also see how he cuts a very small piece of solder wire from the spool, and recommends doing that because he has no way of knowing if there's FLUX in the solder wire right there at the start." - Oh! I've only been picking up the reel of solder, insulated reel so I don't burn my fingers, and simply apply the end of the solder to the item to be soldered for the past 50 years. Meaning I haven't been wasting short bits of solder full of flux.

It depends on how much you care about it, how much solder it's permissible to have at the connection point, how well your soldering is checked, how reliable you want it to be... that standard requires you to cut the solder. 

 

The guy in the video has to respect some standard. You can check this PDF starting from page 18 : https://protostack.com.au/download/NASA Student Handbook for Hand Soldering.pdf

Or you can look at the actual NASA STD-8739.3 - it's interesting read from page 34 onwards : https://nepp.nasa.gov/docuploads/06AA01BA-FC7E-4094-AE829CE371A7B05D/NASA-STD-8739.3.pdf

 

If you just solder something for your own use, relaxed, no stress, no worries if it breaks, you can use solder you have, doesn't matter... even if there's not enough flux right at the start, you'll just feed more solder and eventually you get to flux, but you may get a not quite perfect soldering job. 

I also don't cut my solder, but work around that risk of not having flux right at the start of the wire by simply adding a drop or two of liquid flux on the actual leads or pad which I have to solder. It almost never hurts and flux is so cheap I don't mind adding a drop of liquid flux.

 

[RollyShed]

An interesting discussion.

 

The picture of solder tips, we only ever used the left hand tip.

 

I certainly didn't know and wasn't told about any soldering standards when called in to do jobs for NASA. I simply repaired one job, at least a dozen components had been destroyed when a nut fell into the instrumentation. A bit of a story goes with that one. The other job was upgrading some ESRs in Pasadena.