soldering question

[capriolo]

I'm about to install new LED lights in my Phase Liner 400. I have a Weller station,
a desoldering tool and cardas solder but what I'm wondering about is the need for flux.
I also have some flux core electrical solder at I've used in automotive apps. With the
corrosive property of flux I sure one has to be very careful. Any tips would be greatly appreciated.

Thanks, Mac

[duficity]

proper electical solder is fine. Just dont use plumber's solder and flux. Too much acid.

[capriolo]

Does the cardas solder have some sort of flux in it?

Mac

[jackfish]

Cardas solder has an activated rosin flux core.

[pivot]

I assume the Cardas solder has a rosin core that is the flux and should not be corrosive.

Eletrical solder is mostly rosin core, self fluxing and non-corrosive. Plumbing solder for copper pipes is used with acid based flux and should never be used in eletronics do to the corrosive nature of the flux.

In eletronics kit building I find I like Multicore brand solder with Kester brand a close second.

The "audiophile" solders I have tried in the past have had 2.5% to 5% silver content. These take a higher temperature to flow correctly and I did not like how they "worked". I would rather have a nice shiney well flowed joint with "standard" eletronic solder then a bad joint with "exotic audiophile" solder.

After soldering you can clean up the joints with pure isopropyl aand a toothbrush. Scrub till they shine.

I do use some silver bearing solder, Brownell's "High Force", but only in black powder gunsmithing with a propane or Mapp gas torch. It is used because is is higher strength and I don't think it has made any of the flintlock arms I have used it on sound any better.

[capriolo]

Many thanks for the replies. I think I'll stick with the plain old rosin core electrical solder. I'm sure this info will be of great interest to many.

Maybe some day I will build that tube amp.

Mac

[rhomanski]

What gives the best result, is liquid flux. I have a bottle with a needle in the top to dispense it. I used paste flux for years until liquid became available. Now I won't go back for board work. All of the solder schools I have gone through have stressed that you must use flux with everything. A proper solder joint will be smooth and shiny as soon as it cools. Most mistakes are overtemping and no flux. Alcohol will work fine to remove the residue of the flux, acetone works even faster. That's what your wife uses to remove the nail polish.

Regards,

Ron.

[pivot]

Built a number of kits over decades. My Heathkit VTVM kit from 35 years ago still works a treat.

Assuming the contacts to be soldered are not severly oxidized to start with, there is no need for flux beyond the rosin core in good electronics solder.

Good tutorial here:

http://www.curcioaudio.com/Solder%20Tutorial.pdf

Only time I have used separate flux was when working with surface mount devices. God, but I hate surface mount soldering.

[rhomanski]

I'm not trying to upset anyone Kevin. I scratch built boxes for a aerospace military contractor. Made my own boards and my own boxes from sheet metal. I was given a schematic and dimensions and a handful of parts. All the schools they sent me to always insisted on liquid flux. Inspection wouldn't pass the joint without it. Of course you don't have those picky people looking over your shoulder, and neither do I any more but I still solder as I was trained. They called it High Reliability Soldering. I didn't mind the flat packs twenty years ago, once you get them down they weren't too bad. One guy I knew never could do them he had someone else do them for him. I would like to try the hot air soldering sometime.

Regards,

Ron.

[pivot]

I'm not trying to upset anyone......

Not upset, Ron. No complaints about the technolgy that sent men to the moon or kept the Soviet "workers paradise" at bay.

For myself - in the Hi Fi hobby - I have not needed additional flux beyond the rosin core of the solder itself and IMHO it would add to the complexity.

Using a non-corosive rosin based liquid or paste flux should not be a problem but just seems to create more work to clean things up when done.

[Coffee Phil]

I want to comment on the shiny joint thing. For nearly all my life a shiny joint was a pretty good indicator that all was well with a solder joint. That served me well until RoHS came along. With the new lead free solder most joints look grainy and dull to me even if they are sound. The stuff seems to take a higher temperature to melt. De-soldering components seems to be more difficult with the new solder. In the lab I would sometimes wet solder joints with the old contraband solder to make de-soldering easier. Sence the stuff I worked on was not production my conscience would not bother me about that. At home I have enough of the "good old stuff" to last most of my life (or until I'm drooling on my self in the rest home) so my solder joints can still look good.

Since I am for the most part a Greenie I view the new stuff as an acceptable trade off.

Phil

[capriolo]

All went quite well in replacing 8 little burned out bulbs for 8 LED's. (Except that 2
LED's seem to be a little dim.) I happy to have the UV meters lit up again after almost 20 years in the dark. The most valuable tools for electrical repair is the "Soldapullt" de-soldering tool and the Weller soldering station. Many thanks to all the good folks that chimed in.
Mac

[cats squirrel]

I'm not trying to upset anyone......

Not upset, Ron. No complaints about the technolgy that sent men to the moon or kept the Soviet "workers paradise" at bay..........

in the early days, all joints on 'space craft' were wire wrapped, not soldered, because of the high failure rate of soldered joints. One wonders........

[kelvinMunson]

I'm not trying to upset anyone......

Not upset, Ron. No complaints about the technolgy that sent men to the moon or kept the Soviet "workers paradise" at bay..........

in the early days, all joints on 'space craft' were wire wrapped, not soldered, because of the high failure rate of soldered joints. One wonders........

True Cats, in fact I worked for 35 years in the aerospace industry and a lot of the high reliability kit was/is wire wrapped rather than soldered.