Typewriter Talk / Detached slug solder...

**Posted by thetypewriterman** 26-4-2024 14:20:42

Without any doubt, use a blowtorch. You want a fairly small one, and the kind sometimes sold for cooks to use would be ideal.

**Posted by SoucekFan** 26-4-2024 14:57:49

thetypewriterman wrote:
The correct material is 'tinmans solder', which is 40% tin, 60% lead. However, ordinary electronic solder, which is 60% tin, 40% lead will work just as well in practice.

Which type of core should one choose?

**Posted by thetypewriterman** 27-4-2024 05:19:11

You should be using a flux paste. The main brand here in the UK is 'Fluxite' The resin core in electronic solder does no harm, but when you are soldering steel it won't be good enough on its' own.

**Posted by OlivWriter** 01-5-2024 03:06:18

thetypewriterman wrote:
You should be using a flux paste. The main brand here in the UK is 'Fluxite' The resin core in electronic solder does no harm, but when you are soldering steel it won't be good enough on its' own.

What is this paste used for ? And is it essential ?
And wouldn't tin for small solders be enough ?

**Posted by thetypewriterman** 01-5-2024 15:22:51

The flux paste chemically cleans the metal before you can add a layer of solder. Indeed it is essential. Without it, you are unlikely to get the solder to stick to the metal, especially as you are soldering steel.

**Posted by skywatcher** 01-5-2024 21:53:26

Hi Olivier

The word 'Flux' when used in physics means 'Flow'. The root word is the Latin word 'Fluxus' from which comes 'Magnetic Flux' and 'Luminous Flux'. In our mechanical application of soldering, flux paste allows the melted solder to flow into the gap between the type bar and the type slug creating a strong bond between the two components.

Flux paste for lead alloy soldering comes in 2 forms, active and passive, or acid and rosin. For soldering a steel type slug onto a steel type bar, active or acid flux is required. The acid in the flux chemically removes oxidation from the surfaces to be joined allowing the solder to make a strong mechanical bond between the metals to be joined.

Passive or rosin flux is used in electrical and electronics as the acid in an active flux would eventually eat through the copper of the wires after the repairs have been done causing the repair to fail. Passive flux paste is therefore required for electrical and electronics as it will not rot the wiring. Hope this gives you the basic idea. All the best,

Sky

**Posted by OlivWriter** 02-5-2024 05:32:15

Thank you for your answers, but can we do without flux paste if I only solder with tin ?
Because I read on the internet that the tin is already enriched with a little flux paste...
And is this flux paste toxic ?

THANKS

**Posted by OlivWriter** 02-5-2024 11:36:31

And a little more question :
Should we rather have a tin ratio of 99.3% and 0.7 copper or 97% tin and 3% copper ?
And is copper suitable ?
THANKS

**Posted by thetypewriterman** 02-5-2024 16:31:05

As explained previously, you need tin/lead solder and flux paste. Use anything else and you are on your own.

**Posted by robmck** 02-5-2024 17:19:12

Thanks, Tom.

The only thing I've ever soldered is electronics with good old rosin-core solder, so I'm new to having the flux separate.

For typebars/slugs, is the process that you put paste on both the bar and the slug separately before you put them together? (Then heat it all up and add solder once the flux is bubbling).

For cleaning off old solder beforehand, would a solder wick work just like in electronics?

Thanks!