Should I use flux when soldering in a new cap

[Welchs101]

Hi,

I have a question that i have been wanting to ask for some time. If i am putting in a new cap or IC should i first use flux and then the solder?

If so what type of flux should i buy?

[Th3_uN1Qu3]

Re: Should I use flux when soldering in a new cap

If you use rosin core solder it's not necessary to apply flux because it is inside the solder.

[smason]

Re: Should I use flux when soldering in a new cap

Your solder should already have flux.For caps and standard DIP through hole ICs you shouldn't need any more.
The only time you really need to use additional flux (in my opinion) is when doing surface mount work with really fine-pitch components.

[Welchs101]

Re: Should I use flux when soldering in a new cap

thanks

[severach]

Re: Should I use flux when soldering in a new cap

The flux in the solder isn't able to creep into the holes so all you get is a weak surface solder which is safe for capacitors. I drag the trimmed leads through rosin paste flux to coat the holes so the solder bonds at least part way in. For solder joints like laptop jacks I want to bond all the way through and beyond I preheat the board with hot air.

[mastertheknife]

Re: Should I use flux when soldering in a new cap

I'm not an expert at all but heres my opinion:
The flux in the rosin core is typically very little (2.0% or less) and using own flux might make things easier and result in a better joint.
Flux (even the little flux inside the rosin core) should be cleaned carefully, i use 70% alcohol with q-tips and an old soft tooth brush.
Regarding trimming the leads, the leads should be trimmed before soldering, otherwise the force\movement of cutting the leads might crack the joint.

Just my 2 cents,
mastertheknife

[Toasty]

Re: Should I use flux when soldering in a new cap

Hi,

I have a question that i have been wanting to ask for some time. If i am putting in a new cap or IC should i first use flux and then the solder?

If so what type of flux should i buy?

I do. New work or old work. The extra cleaning doesn't hurt one bit. New or old caps, or any component for that matter, can have oxidation on the leads. Flux gets what you can't see. If you see it, then clean it from the leads first.

I use one in a needle applicator from MG Chemicals:

http://www.circuitspecialists.com/prod.itml/icOid/9735

I also use one from Qualitek in a jar:

http://www.intertexelectronics.com/Q...-oz-P3306.aspx

I think my favorite is the clear thinner one that comes with Chip Quik in the small syringe. I save it for the most special jobs as it's so damned expensive:

http://www.chipquikinc.com/store/prod_smd291.htm

Don't be fooled by the pictures. That's a 10cc syringe which measures D:8mm x L:70mm or 5/16" x 2-3/4". For $15!!

Toast