Solder wick questions

[Axtman]

What is your favorite brand of solder wick? (Currently, I am using Chemtronics Chem-Wik. It is good but expensive.)

How long does solder wick last?

Is there a way to revive old solder wick?

[Greg Robinson]

I find I don't use much solder wick, I tend to prefer my desoldering station or a solder sucker. But when it's what's needed it's indispensable - mostly for surface mount rework in my case.
Anyway, because of my limited use, I've found whatever I buy tends to go stale before I've finished it, even in tiny 5ft rolls, and no matter the brand I've tried or how expensive it's been. This is due to the flux impregnation oxidising.
However, a tiny dab of fresh flux makes it perform like new again. I prefer gel flux for this purpose, I keep a syringe dispenser, as well as paste and liquid fluxes for other purposes. Now I just buy whatever brandname (there's no saving the worst off-brand stuff even with good flux) is cheapest at whichever distributor I'm next ordering from. I'm currently using Chipquik but have zero brand loyalty.

If you use enough volume of it to get through a roll before it expires a better brand may be worth it to you. Also, keeping it in a ziplock bag with a desiccant pack should probably help extend its life, as well as refrigeration (many fluxes require refrigeration to achieve their full advertised shelf-life, check datasheets).

Hope that helps?

[mozz]

Only use chemwix, other brands never worked right. My flux has been sitting on a shelf since 1978. I don't even use it for soldering. Solder sucker sometimes for PCB work but I prefer solder wick.

[g1]

I have some liquid flux in a pill bottle that I just dip the old wick in to. But was just thinking that the flux paste for plumbing solder might work well too. I have a tin of that around somewhere, which I will never use up for plumbing anyway.

[Mick Bailey]

Plumbing flux is fairly aggressive and is usually an acid flux that remains active afterwards, causing corrosion. Maybe worth checking in case it's benign. I've always bought branded desolder wick, but the last batch was from Aliexpress and 10 rolls for less than I usually paid for one. The flux on it was pretty useless, but I always use some SMD rework gel flux with whatever I use as it improves the wicking tremendously.

[J M Fahey]

Please avoid plumbing and in general any non electronics-specific flux.
Most are straight acidic or contain almost as bad calcium chloride which is hygroscopic so attracts atmospheric humidity to corrode area around it.

I make my own by dipping speaker tinsel wire, which I buy in bulk, and soak it into diy rosin paste: pure pine rosin dissolved in pure (94%) alcohol.
No weird chemicals, beautiful smell, works like a charm.

Yes, if left unused long time solder wick degrades.

Not sure it "oxidizes" by the usual mechanism but probably rosin polymerizes in contact with air and becomes something else; just guessing here.

But s fresh immersion in the jam pot (glass body and metal cap, never plastic) filled with liquid flux revives it.
It "should" work on commercial solder wick too.

[Chuck H]

pure pine rosin dissolved in pure (94%) alcohol.
No weird chemicals, beautiful smell, works like a charm.

I love this idea. Not being in the repair biz I've always just used cored solder and I've never had "flux" on hand. I haven't noticed much difference in performance between any "flux" core and "rosin" core solder. Except that the rosin core solder has a pleasant smell and the flux core doesn't seem to have any. One time I did need to flux something and I dissolved a little of a rosin stick I had as part of a polishing kit. Worked just fine but that was in a pinch and I always wondered if I was doing the wrong thing.

EDIT: Do you start with rock rosin or powdered rosin to make your concoction? Should I heat it when mixing? I remember a little heat helped when I made my make shift flux.

[Helmholtz]

I've been using rosin (as used for violin bows) diluted in denatured alcohol since the late 60s.
That's what my books recommended.
Doesn't need to be powdered, but smaller pieces or powder dilute quicker.
No heat required (don't forget: high percentage alcohol is flammable). Shaking helps.
I've actually posted that solder wick trick here a few years ago.

[Chuck H]

I've been using rosin (as used for violin bows) diluted in denatured alcohol since the late 60s.
That's what my books recommended.
Doesn't need to be powdered, but smaller pieces or powder dilute quicker.
No heat required (don't forget: high percentage alcohol is flammable). Shaking helps.
I've actually posted that solder wick trick here a few years ago.

Yes. I did some perusing on the subject after posting.

For bow rosin there are both dark and light (er) products available. I'll guess you use the lighter stuff?

In less develpoped countries some guys actually gather their own rosin right from the trees. They make a thinner solution from it so that it can be run through a filter after dissolving.

And adding 1%-2% glycol (available at many drug stores) will improve performance and reduce smoke

I'm totally going to do this. I may even harvest my own resin since I'm surrounded by fir, hemlock and pine woods here on Whidbey and I'm out mushroom hunting anyway.

EDIT: And I also learned that most people posting on line (including myself before now) don't know the difference between sap, resin and rosin. So... Sap is literally the watery liquid that is in any living tree and not the amber sticky stuff that oozes. That sticky ooz IS the resin. And resin IS rosin. I've been incorrectly calling that stuff sap all my life. So if you have a piece of wood around your building or a tree in your yard with that thick amber colored ooz coming out you could actually use that to make flux.

[Helmholtz]

I just bought the cheapest colophony they had in the violin shop (still was kind of expensive).
Looked brown.
BTW, nice aromatic vapor smell doesn't mean it's healthy.

[Chuck H]

BTW, nice aromatic vapor smell doesn't mean it's healthy.

True! But if you have to be a little unhealthy it could at least smell good I remember one "flux core" solder I had that stunk so bad I still have most of it. I should just toss it but that seems wasteful and environmentally irresponsible. It smells like gym socks boiling in Elmer's glue.

[Mick Bailey]

Years of bench soldering and breathing resin flux fumes full-time gave me a type of respiratory disorder where even the slightest amount now causes a lot of congestion and discomfort and I can be coughing and clearing my throat for days. I now have to use a mask and extractor for soldering. I tried rosin-free cored solder and fluxes (rosin is a known irritant) but they're very poor by comparison.

One of my favourite smells is the flux used on vintage equipment. I had some old rolls of Ersin Multicore form the 60s that smelt like that and had plenty of flux in the cores, unlike most of today's solder. Peavey flux smells nice and they sure used a lot in their power amps.

[Mark Hammer]

Like others here, I will praise the virtues of flux-enhanced solder wick. It is worth taking note that atmospheric/environmental conditions vary widely around the world, across individual neighbourhoods, and in individual homes. Some folks may find that component leads tend to tarnish quickly where they live. The same can be true of solder wick. I keep a small bottle of liquid rosin flux handy. A $10 bottle will last the rest of any hobbyist's' life. I keep a small drawer of cotton-tipped applicators in the parts bin handy as well. The wick doesn't have to be soaked in the stuff. Dip an applicator into the bottle, and brush some flux on a length of the roll of wick and it supercharges the stuff.

Of course, I find the complement to that having a small bottle of methyl hydrate handy, because flux buildup on the board not only looks ugly, but can make it hard to spot unwanted solder bridges. So I grab another cotton-tipped applicator from the drawer, dip it in the methyl hydrate and wipe off any excess flux from the board.

[J M Fahey]

EDIT: Do you start with rock rosin or powdered rosin to make your concoction? Should I heat it when mixing? I remember a little heat helped when I made my make shift flux.

I buy it by the pound at a general purpose chemicals shop, where I also buy acids, acetone, xylene, etc. needed for various tasks but old style Mom and Pop hardware shops also carry it.

I buy amber colour "rock" but the bag always has some powder at the bottom, because it is brittle, so I start with dust and "sand" sized grains to use it within the hour, then add a couple stones and let it slowly dissolve for later use.

In a week or two everything is homogeneous.

I bought 1 kilogram about 20 years ago and still have over a half of it, and that considering I brush a rosin varnish coat on DIY PCBs to protect copper.

After1 or 2 years, unused PCBs (I always make a couple extra of anything) become harder to solder, because protection is not perfect so copper still oxidizes "a little".
If it becomes annoying (say over 2 years old), I wipe rosin away with a cloth/napkin wet in any solvent (alcohol/acetone/toluene/paint thinner), slightly polish copper (which became duller darker) to shiny reddish copper and cover again with fresh rosin varnish.

[Chuck H]

Need two likes Juan