Cable Asylum Interconnects, speaker wire, power cords. Ask the Cable Guys.

---

[ Follow Ups ] Thread: [ Display  All  Email ] [ Cable Asylum ] [ Return to Search Results ]

---

[ Alert Moderator ]

---

Re: Spade/solder/corrosion?

Posted by jneutron (A) on April 22, 2003 at 06:21:00

In Reply to: Re: Spade/solder/corrosion? posted by Jon Risch on April 21, 2003 at 22:39:29:

""What could be happening, is that the heat from the soldering caused the sudden release of a lot of chlorine or other agents from the PVC, and this attacked the wire/solder over a period of time, as it would be partially trapped inside the jacket.""JR

That is a very plausible possibility..

For fluxes, there are three basic types, R, RMA, and RA.

R is non activated, containing usually white water rosin (tree sap) and petroleum jelly (vaseline).

RMA is Rosin, mildly activated. It has the R materials, with the addition of typically Zinc Chloride..Although not limited to zinc chloride, as any halide can and is sometimes used, halides having chlorine, bromine, flourine, or iodine..I've used only chloride based activated solders..And I know hydroflouric acid is very dangerous.

RA is typically water based, and is the most agressive..

Flux serves two purposes, clean the oxide off the surface, and protect the surface from oxygen during the soldering operation..

The cleaning is performed by the conversion of the zinc chloride to hydrogen chloride, this being performed by the heat of the process..This hydrogen chloride helps strip the oxygen from the oxides. Unfortunately, this leaves a hydrochloric acid residue.

With conformal coated pc boards, this can be a huge problem if the acid residue is trapped by the conformal coating..

""In fact, if the wires are literaly covered in flux, they are now insulated from the air, and may be less likely to corrode than before.""JR

I'm not sure of that, but it may be that the hydrogen chloride remains semi-inert unless moisture gets to it, the flux may actually prevent moisture from combining quickly to form acid..

But the military, with conformal coating to seal everything, still requires total elimination of the chloride residue; the conformal coating prevents moisture intrusion.

No-cleans have been formulated to eliminate the final cleaning process with it's chemical disposal issue, and eliminates the acidic residue typical of all RMA's and RA fluxes..

""Kesters 44 flux, a mildly activated rosin based flux (which is what is in the solder I recommedn for cable use), leaves anon-ciorrosive residue that should present no problem on land.""JR

Actually, the residue it leaves is corrosive to a degree..I agree, land based usually presents no corrosion issues.. But, I've seen the green corrosion product under teflon, kapton, pvc, tefzel insulations, as well as along 1 inch by 1 inch braids with no insulation. Which is why I point the finger at the fluxes first..I also recommend Kester 44.

We've a lot of experience here with R type fluxes and cleaning, as they are not allowed within the accelerator ring cryogenic system..The residue from RMA flux corrodes the stainless steel expansion/contraction bellows. Unfortunately, another collider facility did not consider it, and started getting vacuum leaks..BTW, fingerprints also corrode the stainless steel.

If you'd like more info, I can look for it in my paperwork, but it's kinda buried...I'm sure there are some web sites that can confirm my unfortunately long "diatribe", but don't bother with my employer's website, as I wrote the specs. If I were wrong on any points here, you'd only be validating incorrect info..

Cheers, John

This post is made possible by the generous support of people like you and our sponsors:

Herbie's Audio Lab

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---