Soldering Resistance Wire And Stainless Steel - UK Vintage Radio Repair and Restoration Discussion Forum

JHGibson · 17th Oct 2003, 5:45 pm

When it comes to soldering resistance wire and similar alloys like stainless steel, I find that the common electrical fluxes are useless. I discovered that Naval Jelly, usually used for removing rust, makes a excellent active flux for these alloys.
The fumes given off during soldering with Naval Jelly are very irritating and toxic so the job is best done outside. The flux residue should be removed by scrubbing with a toothbrush and hot detergent water followed by a clean water rinse.
Once the items have been tinned by this method, they can subseqently be soldered into place with ordinary flux and solder.

Alan_Douglas · 23rd Nov 2003, 10:34 pm

I've used stainless steel flux and "radiator flux" (for repairing auto radiators) for the same purpose. I believe they're both hydrochloric acid and zinc chloride. Likewise, once the part is tinned, and the acid washed off, ordinary solder will bond to it. This also works for retinning plated soldering iron tips.

JHGibson · 24th Nov 2003, 5:40 pm

The principal ingredient in Naval Jelly is phosphoric acid. This what is used in specialised stainless steel fluxes but Naval Jelly is infinitely easier to find. Zinc chloride and hydrochloric acid are great for tough soldering jobs but I found that they will not touch stainless steel.

Alan_Douglas · 27th Nov 2003, 1:10 am

I just checked the bottle at work: Kester formula 817 "Stainless Steel Soldering Flux" lists only two ingredients: hydrochloric acid and zinc chloride. It works on 303 stainless at least.

JHGibson · 27th Nov 2003, 9:59 pm

I was curious as to why Alan's Kester 817 hydrochloric acid plus zinc chloride would solder stainless steel but my plain hydrochloric acid with zinc chloride would not. I looked up the composition of Kester 817 on their web site and found the composition to be:
Zinc chloride 37%
Hydrochloric acid 5%
Ammonium chloride 3%
The ammonium chloride must give the 817 flux the extra kick!
So to solder stainless steel use Naval Jelly or the Kester 817 flux recommended by Alan.

17th Oct 2003, 5:45 pm	#1
JHGibson Retired Dormant Member Join Date: Apr 2003 Location: Salt Spring Island, BC, Canada Posts: 368	Soldering Resistance Wire And Stainless Steel When it comes to soldering resistance wire and similar alloys like stainless steel, I find that the common electrical fluxes are useless. I discovered that Naval Jelly, usually used for removing rust, makes a excellent active flux for these alloys. The fumes given off during soldering with Naval Jelly are very irritating and toxic so the job is best done outside. The flux residue should be removed by scrubbing with a toothbrush and hot detergent water followed by a clean water rinse. Once the items have been tinned by this method, they can subseqently be soldered into place with ordinary flux and solder.

23rd Nov 2003, 10:34 pm	#2
Alan_Douglas Retired Dormant Member Join Date: Nov 2003 Location: Cape Cod, Massachusetts Posts: 59	Re: Soldering Resistance Wire And Stainless Steel I've used stainless steel flux and "radiator flux" (for repairing auto radiators) for the same purpose. I believe they're both hydrochloric acid and zinc chloride. Likewise, once the part is tinned, and the acid washed off, ordinary solder will bond to it. This also works for retinning plated soldering iron tips. Last edited by Paul Stenning; 26th Dec 2004 at 11:55 pm. Reason: Fix link or code for vBulletin

24th Nov 2003, 5:40 pm	#3
JHGibson Retired Dormant Member Join Date: Apr 2003 Location: Salt Spring Island, BC, Canada Posts: 368	Re: Soldering Resistance Wire And Stainless Steel The principal ingredient in Naval Jelly is phosphoric acid. This what is used in specialised stainless steel fluxes but Naval Jelly is infinitely easier to find. Zinc chloride and hydrochloric acid are great for tough soldering jobs but I found that they will not touch stainless steel.

27th Nov 2003, 1:10 am	#4
Alan_Douglas Retired Dormant Member Join Date: Nov 2003 Location: Cape Cod, Massachusetts Posts: 59	Re: Soldering Resistance Wire And Stainless Steel I just checked the bottle at work: Kester formula 817 "Stainless Steel Soldering Flux" lists only two ingredients: hydrochloric acid and zinc chloride. It works on 303 stainless at least. Last edited by Paul Stenning; 26th Dec 2004 at 11:56 pm. Reason: Fix link or code for vBulletin

27th Nov 2003, 9:59 pm	#5
JHGibson Retired Dormant Member Join Date: Apr 2003 Location: Salt Spring Island, BC, Canada Posts: 368	Re: Soldering Resistance Wire And Stainless Steel I was curious as to why Alan's Kester 817 hydrochloric acid plus zinc chloride would solder stainless steel but my plain hydrochloric acid with zinc chloride would not. I looked up the composition of Kester 817 on their web site and found the composition to be: Zinc chloride 37% Hydrochloric acid 5% Ammonium chloride 3% The ammonium chloride must give the 817 flux the extra kick! So to solder stainless steel use Naval Jelly or the Kester 817 flux recommended by Alan.