[SPEC ME] Flux paste for electronics / SMD stuff, that isn't too expensive.

Doctor McNinja

Doctor McNinja

Doctor McNinja

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TL;DR I'm after some flux paste for use with electronics. I'd prefer something that's easy to work with / doesn't require scraping and diluting with IPA, and if possible... I'd like to keep it under £5. And the cherry on the cake would be not having to wait a month for it to come from China.

I've finally decided to get myself a soldering station (after a couple of bodge jobs with a back of the garage, old as the hilss iron). I've got the soldering station (with sponge and brass wool), I've got the rosin core solder, I've got some solid core 22awg wire from the 'bay, and I've got some 2mm wick... all I need now (I think) is the flux but I'm kind of struggling to see the wood for the trees. There's so much available, ranging in price from a couple of quid to a tenner or more, and it's sometimes hard to tell if a given product is forelectronics or for plumbing/brazing (no thanks to amazon for recommending the latter when buying supplies for the former). The results I'm getting that are specifically for SMD work, are solid blocks of rosin rather than paste. I'm also note sure whether it's worth spending £10 when there might be £2 options out there that will get the job done.
 
The type of flux makes absolutely no odds whatsoever- It all does exactly the same job.

Key points:
  • If you can, use leaded solder. Lead free stuff is absolutely terrible.
  • Use as little flux as possible. Biggest mistake people tend to make is having far too much on there.
  • Use the right size iron tip. If you're trying to solder silly small stuff, the default tip is far too fat. (If you're good, you can get away with a much larger tip than needed)
  • Use the right wattage. Goes with the tip size above, no use trying to heat up a massive lump of steel / nickel silver with a poxy wattage and tip size.
Liquid flux is slightly easier to work with in some cases (as it wicks into stranded wire a little more & is easier to get away with excess), but as you have to ask the question, it makes absolutely no odds to you :p

(Plumbing / brazing flux is exactly the same thing, just comes in a bigger and cheaper tub)
 
I spent nearly 30 years designing electronics and only ever used a small pot of flux on the soldering station for cleaning the iron tip.

A good iron (Weller) and some quality multicored solder & you're sorted ( I used to do 208 pin QFP with no problems)
 
mrgubby said:
I spent nearly 30 years designing electronics and only ever used a small pot of flux on the soldering station for cleaning the iron tip.

A good iron (Weller) and some quality multicored solder & you're sorted ( I used to do 208 pin QFP with no problems)
Click to expand...

This. Anything else is faffing.
 
Out of interest what station/iron have you gone for?

I have a couple of projects I want to do (nothing SMD level) and want a decent but reasonably priced hobby iron.
 
I've ended up getting some Mechanic brand flux.

leezer3 said:
The type of flux makes absolutely no odds whatsoever- It all does exactly the same job.

Key points:
  • If you can, use leaded solder. Lead free stuff is absolutely terrible.
  • Use as little flux as possible. Biggest mistake people tend to make is having far too much on there.
  • Use the right size iron tip. If you're trying to solder silly small stuff, the default tip is far too fat. (If you're good, you can get away with a much larger tip than needed)
  • Use the right wattage. Goes with the tip size above, no use trying to heat up a massive lump of steel / nickel silver with a poxy wattage and tip size.
Liquid flux is slightly easier to work with in some cases (as it wicks into stranded wire a little more & is easier to get away with excess), but as you have to ask the question, it makes absolutely no odds to you :p

(Plumbing / brazing flux is exactly the same thing, just comes in a bigger and cheaper tub)
Click to expand...

I've only got the solder that came with the iron at the moment. It's Sn63Pb37 solid core.

In regards to plumbing / brazing flux... everything I've read has said that it's more acidic and shouldn't be used for electronics work as it can cause corrosion over time.


mrgubby said:
I spent nearly 30 years designing electronics and only ever used a small pot of flux on the soldering station for cleaning the iron tip.

A good iron (Weller) and some quality multicored solder & you're sorted ( I used to do 208 pin QFP with no problems)
Click to expand...

The iron I ended up buying came with some wire. It's solid core Sn63pb37. I've tried tinning the tip using various techniques, inlcuding ones from Weller themselves, using different temperatres, using the brass wool, the sponge, both, with varying amounts of flux... but when the solder drys / cools, it turns dull and grey rather than a nice shiny silver. I'm not moving the iron around or blowing on it as it cools... Could it be the wire itself (as it's probably the cheapest of the cheap that they include with stations such as the one I bought)?

[EDIT] I should just mention that after I've cleaned the tip either on the sponge or using the brass wool, it looks nice and shiny, and free from oxidation.

Dup said:
Out of interest what station/iron have you gone for?

I have a couple of projects I want to do (nothing SMD level) and want a decent but reasonably priced hobby iron.
Click to expand...

My budget for the iron was £40 and all the ones I was looking at online appeared to be basically the same design, albeit with a different name and different accessories. I ended up going with this iron because it had the basic features I wanted, and when I bought it, it was on a lightning deal for £28. Whether it's actually and good or not, only time will tell.

https://www.amazon.co.uk/gp/product/B08LQ7Z7QW/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
 
Last edited:
Doctor McNinja said:
[EDIT] I should just mention that after I've cleaned the tip either on the sponge or using the brass wool, it looks nice and shiny, and free from oxidation.
Click to expand...
What you're describing is perfectly normal. I use a damp sponge and I wipe the tip each time I use it.

I've been soldering since my early teens and not once have I needed to use separate flux, I just use normal leaded fluxed solder.

8nKaZBn.jpeg

Make sure you use the right size tip, make sure it's always tinned and you're good to go.
 
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