[DaKi][er]

Quote:

Originally Posted by RnB180 I tin my iron tip before soldering, Radio shack solder flows evenly and has a low melt temperature, But the flux they use is extremely corrosive IMO. Ive found that its alright ot leave a blob on solder on the tip. Just dont leave it too long. I do that right before termination. People advise against it because its high potential for a dry joint. In which the solder is exposed to a heat too high for it to stay inert and the components in the solder start seperating. But I never leave it on the tip longer then a second or so. You can pretty much spot a dry joint by its discoloration and texture. A cold not will not be shiney and it will be convex. A dry joing just looks ugly. I usually tug on the joint to ensure its a strength afterwards.

The components in the solder dont start to seperate, what you get there when you leave the heat on the solder for too long that it goes real tacky and brittle like is just the flux burning up, so if that ever happens all you need to do is add a bit more flux (this is where having extra to add comes in handy) will make the solder flow back to how it was when you first melted it off the roll and leave you with perfect results
All a cold joint needs in the end is some flux on it and a reflow

 

[jl123]

What I do is put the tip on the joint and almost at the same time touch the solder directly to the tip to get that small amount on the tip allowing for better heat transfer. I then touch the solder to the pad and component lead. This way I get nice results without having to retouch the joint with extra flux.


Maybe this subforum should have a soldering FAQ type sticky.

 

[RnB180]

Quote:

Originally Posted by DaKi][er The components in the solder dont start to seperate, what you get there when you leave the heat on the solder for too long that it goes real tacky and brittle like is just the flux burning up, so if that ever happens all you need to do is add a bit more flux (this is where having extra to add comes in handy) will make the solder flow back to how it was when you first melted it off the roll and leave you with perfect results All a cold joint needs in the end is some flux on it and a reflow

are you sure about that? I learned this from my electronics college professor. Isn't the reason it gets brittle "is" because the solder begins to lose its compositon?

 

[mono]

Quote:

Originally Posted by RnB180 are you sure about that? I learned this from my electronics college professor. Isn't the reason it gets brittle "is" because the solder begins to lose its compositon?

Depends on definition of composition. You lose the flux, so if you were to add flux to the part you'd still get a good joint, or you might have longer time on the iron if you used normal solder. Less active fluxes, like clear no-clean type are not as good for general purpose use and you've found it takes a lot of extra effort to end up with near (but not same) quality joints. Regular Radio Shack solder will do better than what you're using.

That corrosive flux which you dislike, is actually only a median active flux which is there for good reason. To use a less active flux and get same quality joint one must heat the parts longer or not just clean them but actually remove the surface oxidation even on "new" parts. Not all parts require t his of course, taking gold as an example, but otherwise using the less active flux is a concession made to have lower quality result so it doesn't have to be cleaned off. That is good news when the parts can't be washed later but such solder should not ideally be used any time parts can be cleaned off later.

The idea will be to use solder with reasonably active flux and if the finished assembly has parts intolerant to washing, the board is washed of flux prior to those parts being added, and then finished up with the no-clean low-activity flux or cleaned much more carefully.

Don't eat solder. Touching it is not a problem, shouldn't even be a problem if one hasn't washed their hands in a long time. The problems tend to come from deviation of standard good practices like choosing the wrong solder or flux.

 

[DaKi][er]

I'm trying to think back to my material science and I cannot recall anything like that happening in any metal alloy, Pb and Sn are completely soluble in each other above the melting point of the alloy. But you don’t really need to go into the science and chemistry of it, try it and you'll see that it does work

Put some decent amount of solder on your iron, leave it sit there for as long as you want, paste some flux on the joint you want soldered and with this 'bad' solder on the iron try soldering the joint and you'll see it works perfectly

 

[RnB180]

I dont get dry joints or any problems with adhesion with the cardas or radio shack I know that when I first started using the radio shack it ate the soldering iron tips away, this probably means its a really active/high strength acid in the flux.. The hakko is really a good station. so whatever means a dry or cold joint needs to repair itself is a good thing.

Ive had no issues with Cardas solder so Im staying with cardas solder

until the July 2006 then I have to switch to lead free solder. I have to see if my WBT is Rohs compliant.

 

[jl123]

Looking foward to moving to RoHS compliant.

It's voluntary in north america right? Maybe I heard wrong.

Have anyone even tried any leadfree solders and like it?

 

[Zorander]

The solder I purchased off DSE Australia is lead-free, though being a soldering newbie, I cannot appreciate any difference with 'regular' solder (which I've never used).

 

[mono]

Quote:

Originally Posted by jl123 Looking foward to moving to RoHS compliant. It's voluntary in north america right? Maybe I heard wrong. Have anyone even tried any leadfree solders and like it?

There's noting to like about it, except for that obvious (but arguable) part of no lead getting back into the environment. There's nothing to look forward to.

 

[AndrewFischer]

Quote:

Originally Posted by jl123 Looking foward to moving to RoHS compliant. It's voluntary in north america right? Maybe I heard wrong.

Anything sold in Europe must be lead free starting soon (July 2006?)

 

[cosmopragma]

Quote:

Originally Posted by AndrewFischer Anything sold in Europe must be lead free starting soon (July 2006?)

Yes, and each DIYer has already a few pounds of usable solder stored in his drawer.
Just another EU blunder, and we are used to circumvent the idiots.

 

[jl123]

I'm pretty sure any of thier restrictions are voluntary in north america. Of course if any products want to be sold in europe then we'd have to comply(July 1st 06). Ive tried lead free and I hate it. And yes I have a few pounds of leaded solder.

Heh. I was being sarcastic about moving to RoHS compliant.

 

[binkgle]

what's so bad about leadfree solder?

 

[cosmopragma]

Quote:

Originally Posted by binkgle what's so bad about leadfree solder?

Nothing as far as new soldering machines are concerned.
Besides of that, just everything.
It's more expensive itself, but the economical costs are much higher than the costs of the solder.
Small companies won't be able anymore to manufacture hand soldered small series of devices, or at least the costs will be much higher.
Many older machines are not adjustable to the new specs.
It's hard to use for hand soldering.Each DIYer that has tried it hates it.Admittedly you might get used to it after a few dozends hours of practise, but I guess many will give up and teens trying to get into DIY will be scared off.
And the best is : it's totally unnecessary.More than 95 % of environment pollution is caused by lead on the roofs.Plus the new garbage dumping sites in central Europe are totally sealed anyway, and from 6/2006 on we are forced to collect our electronical garbage and it will be treated separately.
Estimated costs of all this blunder for the next ten years : 100 billion.
Without any measurable positive effect on the environment.
We call it Eurocracy, and we love it.

 

[jl123]

Well said...lol