Soldering

Baker's fluid, which I have a feeling is zinc chloride/HCl ?

Some of the newer fluxes for plumbing with lead-free solders seem a bit more agressive than yorkshire flux, could be worth a try if you can't lay your hands on baker's fluid or equivalent.

Cheers Tim

Cheers Tim Tim Leech Dutton Dry-Dock

Traditional & Modern canal craft repairs

I have put a few pics of the offending article here:-

Baker's Soldering Fluid is not as easy to get as once it was, but you can still get it from plumbing suppliers. There is no substitute for cleaning ferrous metal in my view.

Regards,

Kim Siddorn

Old books recommend all sorts of obscure and dangerous chemicals but I'd use a similar approach to that used for ensuring a good bond between CI and whitemetal. Ammonium Sulphate (very aggressive and the fumes will take the skin out of your nose), as a wet paste, scrubbed in with a fine wire brush during the tinning process (of each part separately). I'd also suggest cleaning by hand only using sandpaper or a file and preceded by a dunk in strong boiling caustic then a rinse. ttfn Roland

In message , Nick Highfield writes

You could try making your own 'killed spirits of salt' - Zinc Chloride. Get some Hydrochloric Acid and drop in Zinc metal (carefully) until the fizzing stops. Do not smoke or otherwise expose to ignition sources - the 'fizzing' is caused by the evolution of Hydrogen gas. I think that Zinc Chloride is at the heart of things like Baker's flux.

Alternatively, get some Zinc Chloride and make an aqueous solution of it.

You'd need it all fairly warm, especially the cast iron - probably about the 350 degree C mark...

HTH

Pete

Killed spirits of salt, that rings a bell, one of those lethal sounding recipes to be found in the likes of Newnes "Practical Enquire Within" (a fine set of books which instruct the reader on everything from repairing boots to stuffing a bison). Think I'll see if the local plumbers merchant sells Bakers fluid first!

My dad could solder practically anything even vaguely capable of being soldered to anything else - I saw him solder carburettor zinc to copper sheet, something I've never been able to do! - and he taught me about making cables for motorcycles, the inner wire being saturated in oil, of course, and repeated heatings and dunkings in Bakers would do it everytime.

"Cleanliness is next to Godliness" is a maxim for the user of lead/tin solders.

Regards,

Kim Siddorn

I'd rather have a free bottle in front of me than a free frontal lobotomy!

But where do you find zinc metal these days ? Apart from sacrificial anodes on a boat or scrounging from a galvaniser's, there aren't many easy sources for it in a usably pure form.

BTW - if you think Baker's fluid is toxic, take a look at silver-soldering fluxes. Hot fluorides ! Yum !

-- Die Gotterspammerung - Junkmail of the Gods

There is an easier way to joint two dissimilar metals, Its called Pop Rivets :-))

Sorry Gents could not resist,

Martin P

The big problem is the CI. The graphite smears across the surface and prevents tinning, as we know only too well when tinning CI shells for re-babbitting. We shot-blast with chilled angular iron grit to knock out the surface graphite, but scouring with a drum sander can work OK. Roland is quite right in that a boiling caustic solution helps. A dutch bearing repairer I know swears by boiling the CI in the caustic solution for up to an hour. You have to rinse, rinse & rinse again though. The caustic permeates the CI and if a trace is left it can come back to haunt you. Bakers fluid is not as aggressive as a Zinc & Ammonium chloride mix with a dash of hydrochloric plus a drop of wetting agent. Even then the tinning is no pushover. Usually persistence will win & when the CI is tinned, the mild steel will seem easy. There are, though, in our experience, rogue CI's that will never tin well. That's why so many CI bearings are designed with dovetail anchorages.

Phil

Thanks for correcting my poor memory Phil. The flux I got from Hoyt's has not failed yet It is, as you say, extremely aggressive and corrodes anything it touches! ttfn Roland

Pop Rivets? One of Billy Childish's early groups ISTR!