What type of solder should I use for this type of repair ?

[l3gi0n]

I am repairing some game controllers. I want to replace the analog sticks. The newly soldered analog stick might get replaced again in the future...

Should I use Kester 245 which is no-clean or Kester 44 which is rosin core ? The datasheets for both state that cleaning is not required and a saponifier must be used to clean the residues. Will I have any problems with flux residues if I want to replace the stick multiple times ? Would flux residue buildup be a problem ?

Does the type of flux even matter in this situation ?

[james_s]

It really shouldn't matter, any general purpose rosin core solder should work fine. If flux buildup becomes an issue you can clean it, but generally it isn't an issue, you will probably wear out the board before you'll end up with enough flux on it to be a problem.

[flolic]

I fixed literally hundreds of PS4 controllers and replaced who know how many analogs on them. Flux residue is of no worry, you don't need to clean it.

[l3gi0n]

It really shouldn't matter, any general purpose rosin core solder should work fine. If flux buildup becomes an issue you can clean it, but generally it isn't an issue, you will probably wear out the board before you'll end up with enough flux on it to be a problem.

I am a bit confused here...No-Clean is a type of rosin core ?

Is Kester 245 Rosin core ?

[james_s]

Yes, to my knowledge all electronics soldering fluxes are some kind of rosin.

Directly from the Kester spec sheet:
"Kester 245 was developed to complement low residue liquid fluxes being used by the electronics industry. The chemistry is based on some of the same principles that have been safely used for years in mildly activated rosin fluxes. The use of 245 results in visually acceptable assemblies without cleaning, yet soldering quality and efficiency is comparable to that obtained with mildly activated rosin flux. 245 is classified as ROL0 per J-STD-004. 245 is Bellcore GR-78 compliant.:

I interpret that as being some form of synthetic rosin.

[tooki]

Yes. The datasheet says it’s ROL0, which means rosin, low activation, no halogen.

[tooki]

Yes, to my knowledge all electronics soldering fluxes are some kind of rosin.

That is incorrect. Some are synthetic resin (with an e, not an o), which are chemically similar to rosin. Almost all water-soluble fluxes are resin- and rosin-free. Many liquid no-clean fluxes contain no rosin or resin, either, same with some tacky/gel no-clean fluxes.

[l3gi0n]

Since you are saying any Rosin core solder can get the job done, should I go with a cheap solder on amazon.ca ?

the Kester is kind of expensive... My only concern is whether cheaper solder are more hazardous to health than the expensive ones ?

What is your recommendation ? should I go with a cheap solder or a Kester ?

[james_s]

You cannot judge health risks by price, although any solder is potentially hazardous to your health if you eat it, and any solder should be perfectly safe to use in a sensible manner. Kester makes a quality product with reliable specifications. They are not the only good solder brand out there though. I would generally avoid the really cheap stuff, you never know quite what you're going to get. When considering the cost, be sure to factor in how long it will last. I'm an avid hobbyist and a 1lb roll of solder lasts me around a decade typically. Even if I pay $100, that breaks down to $10 a year, under a dollar a month.

[Wallace Gasiewicz]

Rosin is just cooked pine trees. It is used in lots of stuff and was used in shoes. I think baseball pitchers still use it. You can develop a skin allergy to the stuff. So synthetic Rosin was developed. Turns out you can develop a skin allergy to that. All in all it is really safe stuff and has been use safely for a long time,probably hundreds if not thousands of years. I think the ancient Greeks used Rosin to seal their wine jars.
Major problem with solder is always the lead. Multiple studies of electronic workers who soldered for their entire shifts showed no elevated lead levels. Most of this soldering is not lead any more and is not done by humans. Lead has been phased out of auto body production and other processes a long time ago. Battery recycling is the biggest lead hazard I know of presently and workers are still tested and this is a potentially hazardous occupation.

Some Tektronics scopes had some sort of solder post that was ceramic??? and it had silver in it. you needed solder with a few percent of silver in it for soldering to these things.  I have not actually done this. Otherwise solder is solder and any will probably be just fine.

[wraper]

Rosin is just cooked pine trees. It is used in lots of stuff and was used in shoes. I think baseball pitchers still use it. You can develop a skin allergy to the stuff. So synthetic Rosin was developed. Turns out you can develop a skin allergy to that. All in all it is really safe stuff and has been use safely for a long time,probably hundreds if not thousands of years. I think the ancient Greeks used Rosin to seal their wine jars.

Rosin is not safe at all when its vapors are inhaled. Also there is some other toxic stuff added to the fluxes. Expensive flux does not mean it's safe when inhaled. It's just that some cheap Chines flux may be on an other level of danger as nobody cared what toxic stuff was added.

[tooki]

Since you are saying any Rosin core solder can get the job done, should I go with a cheap solder on amazon.ca ?

the Kester is kind of expensive... My only concern is whether cheaper solder are more hazardous to health than the expensive ones ?

What is your recommendation ? should I go with a cheap solder or a Kester ?

Even “expensive” solder is cheap: the amount used per project is tiny. Solder costs essentially nothing compared to the components it’s used with. For this reason, I don’t understand the motivation to seek out the absolute cheapest solder possible. It’s not worth it.

Kester isn’t “cheap”, but it’s hardly the most expensive, either. When people say it’s expensive, I actually wonder if they’re forgetting to look at package sizes, perhaps comparing a 1/4lb or 100g spool to a 1lb or 0.5kg spool and not realizing it.

Any name brand solder is fine (Kester, Multicore/Loctite, Alpha, AIM, Indium, Stannol, Almit, ChipQuik, Tamura Elsold, Asahi, etc.) Even Radio Shack solder is fine (but it’s actually fairly expensive per g).

A 1lb roll of 63/37, 0.79mm Kester 44 is around $50 on Digi-Key (which isn’t known for low prices) right now, but a roll lasts me years and years at home (I’m currently on a roll bought in 2015), so plain and simply, who cares?

[BrokenYugo]

I would not recommend a beginner use cheap off brand solder, simply because it adds another variable and may make things more difficult.

You really don't need to overthink this, if the datasheet says the residue is non corrosive and non conductive then it is for all practical purposes and you won't have a problem with it in any circuit you're going to find in consumer electronics.

Personally I prefer a fairly strong flux for repair work, like 44.

[james_s]

Some Tektronics scopes had some sort of solder post that was ceramic??? and it had silver in it. you needed solder with a few percent of silver in it for soldering to these things.  I have not actually done this. Otherwise solder is solder and any will probably be just fine.

They aren't posts, they're ceramic strips with V shaped grooves in them that are plated with silver. Components are installed spanning a pair of strips and connected point to point.

[David Hess]

I am repairing some game controllers. I want to replace the analog sticks. The newly soldered analog stick might get replaced again in the future...

Should I use Kester 245 which is no-clean or Kester 44 which is rosin core ?

Either will work fine whether the flux is cleaned or not.  Kester 44 will be easier to use because the more active flux will allow easier soldering.  Kester 245 is more suited to new parts and boards than rework.

For any solder joint that undergoes mechanical strain, I prefer to use common 2% silver lead-tin solder (Sn62Pb36Ag2) because it is much stronger and less likely to crack.

The datasheets for both state that cleaning is not required and a saponifier must be used to clean the residues. Will I have any problems with flux residues if I want to replace the stick multiple times ? Would flux residue buildup be a problem?

There will be no problem with the flux residue of either.  I would likely clean with acetone, lacquer thinner, or flux thinner using a cotton swab to make inspection easier.

Does the type of flux even matter in this situation?

Water soluble flux is acidic and would need to be cleaned because otherwise it would corrode.

[abdulbadii]

Does the type of flux even matter in this situation ?

Not at all

but it'd be good habit to always clean up the soldered part at the end of work with medium percentage IPA regardless of the flux type

[paul_g_787]

I always use Rosin core 60/40 lead solder. Usually Multicore/loctite brand.

I just clean up the flux with IPA and cotton swabs after.