Solder Wire Flux Content

[jnv108@gmail.com]

I need to buy solder wire and this is very confusing. I would like to buy 0.5mm solder wire, but how much flux needs to be inside the wire?

1% 2% 3%


- Is 1.2% flux on the solder wire good enough for a beginner?

[NB: I am planning to just play around with circuits, and teach myself some basic electronics. ]

I am new to electronics and soldering ETC. I have just bought myself a Dick Smith Soldering iron

http://www.dicksmith.com.au/tools-hobbyist/temperature-controlled-soldering-station-dsau-t2200

[Fsck]

most people will add flux any time they solder (either pen or bottle with a fine tip, etc) so it doesn't really matter in general.

[jnv108@gmail.com]

Hi

Thanks for the reply.

I will be getting a flux pen anyway. But what % would you suggest included in the solder wire itself?

[Fsck]

I use kester 44, which typically comes with 3.3% flux by weight.

[DanielS]

I will be getting a flux pen anyway. But what % would you suggest included in the solder wire itself?

The more flux you have in the solder itself, the less likely you are to need to add any in a typical soldering job. If you are going to solder on bare copper a lot, such as tinning copper wires, use the highest-flux solder you can find so extra solder will add extra flux to help solder wick all the way through. If you are going to be soldering mostly on tinned copper or will be applying your own flux either way, you can skip flux in the solder wire altogether.

I have 3% rosin solder wire and practically never need flux for soldering unless the surface I am trying to solder to is in pretty bad shape - usually need to give it a good scraping first in those cases.

[G7PSK]

You cant go wrong with "more flux the better" in the solder. Also particularly at first very fine solder is hard to manipulate and feed into the joint learn to solder using .9 solder go to .5mm as your skill improves.

[David Hess]

The only time I would use solder with a smaller sized flux core would be in a production environment where the surfaces of the boards and parts are of a known quality.  In any other application, I would use the largest flux size available.

My favorite is Kester 44 with core size 66 which is 3.3% by weight.