Silver Solder Stocks

When I took up silver soldering many years ago I was advised to use a cadmium free solder on stainless steel. I never had any failures using this solder but did when using a cadmium containing solder on a couple of joints.

The joints looked OK with nice shiny fillets etc. but had next to no structural strength.

Whether the cadmium is the problem I can't be sure but I am happy to avoid it as most of my work is with stainless steel.

Pero

I can't answer that from a group perspective. From my personal perspective, I like to use Cadmium bearing Silver Solder because it has always produced better joints than the 'Cadmium Free' replacements. Practical engineers use hazardous materials and/or processes on a regular basis, the key to keeping safe whilst doing so is to understand the risk and mitigate it; Johnson Matthey's paperwork for these products has always recommended localised fume extraction, which is a good idea for most/all hot work.

WRT Pero's comment, I have never had a joint failure with a Cadmium Silver Soldered Stainless steel yet, but if very high joint strength was the key requirement I would be inclined to TIG weld it.

Edited By Stueeee on 23/07/2021 08:21:37

Edited By Stueeee on 23/07/2021 08:41:41

Hi Stueeee

Probably every model engineer in the country would like to be able to buy some cadmium bearing silver solder.

I've been unsuccessful when trying to find your source with a simple google search. What do you type into google?

Why doesn't your supplier advertise it? It's a shoe-in that he will shift his stock very quickly. In the last 2 weeks before its sale was banned, I sold 40 kg - 4800 rods. Average monthly sales to the model engineer was 10 kg

I would like a quotation for all his stock because there is not a manufacturer in Europe. Johnson Matthey "the Easi-flo people" have, in the past, been very jealous of their trade name. Want to see the file? I believe they have relinquished their trade name

Assuming there is provenance, he provides an invoice and bank details, I am prepared to buy all his stock NOW.

Don't be coy. Send me a personal message. I don't want the rest of the world, including HSE and Trading Standards, to know.

Who is the supplier?

You will be doing him an enormous favour.

Who knows, there might be a nice little earner in it for you.

Keith

PS Sadly I do not expect any response, a feeling, I'm sure, that will be shared by the aforementioned bodies because when I know, they will.

PPS SELLING THE STUFF IS ILLEGAL

I believe it is also illegal to buy ( unless approved user) and even give it away to someone.

Keith PM sent with source.

Edited By JasonB on 23/07/2021 10:25:56

Keith, and other interested members, I didn't put the hyperlinks up simply because there seem to be convoluted rules about such things on this site. However, putting this search term on UK ebay should find it:

Mod Edit Search phrases removed as they will take you to illegal sales.

I found the the other supplier from this Google search:

For me, the supplier came up as the third or fourth result.

Cadmium bearing Silver Solder is still available in the USA, but I didn't find anywhere that had it in stock when I was last out there in 2019. Lucas Milhaupt are a major manufacturer in the US and their HQ was on my doorstep, but their 'customer service' people turned out to worse than useless with my product specific query.

Edited By JasonB on 23/07/2021 10:25:15

Wonder how many Muddle Ingineers who made boilers in the past have died of Cadmium poisening? Rather unfortunate that those of us with half a brain cell have to be penalised to safeguard the dipsticks.

Regards Ian.

Stueeee, Please PM Keith details of the model engineering supplier, I have sent him the e-bay link.

I did find a model supplier though not what I would call ME, more RC selling Easy-flo No2 but in the next line the uses for Silver-flo are given so who knows what you may get.

its hard to say as it is a known cause of cancer - do you know of any model engineers who have died of cancer!!

Cadmium and its compounds are highly toxic and exposure to this metal is known to cause cancer and targets the body's cardiovascular, renal, gastrointestinal, neurological, reproductive, and respiratory systems.

Like everyone else I was once very blase about using really poisonous metals, even mercury which was recognised as nasty. As for lead, cadmium, berylium, they were very useful and quite harmless. I became aware of cadmium's toxicity when villagers on the Mendips were told "on no account" to eat their home grown vegitables.

Although lead paint is better than titanium oxide paint, copper berylium makes very good springs and cadmium silver solder is easy to use I would not, now, use them.

Before I retired the banning of chrome plating was being consider because of the problems of chromic acid.

JA

Edited By JA on 23/07/2021 11:46:19

Hi, so here's a question that others may be interested in; what does one do with silver soldering rods that can't be identified, which may contain Cadmium? I do have a bunch of silver soldering rods that I obtained from my old place of work many years ago, before the Cadmium ban was in force, they had to be taken off site or sent with other things that didn't have any safety / material information data and no identity, which had been in the stores for many years.

Regards Nick.

Following a phone call to the supplier concerned in the Northants area, yes it's right.

42% silver cadmium bearing silver solder rod, as of 11.00am, was available.

A rod 0.7mm dia x 600 was £9.99 per rod.

Why put yourself at risk, when you can braze safely using a 55% silver, cadmium free alloy that costs £4 ish for a 1 metre length of wire or £15 for 5 rods 500mm long?

Can't see the point of telling you where to get this bargain. I suspect that it might not be available for long.

Edited By Keith Hale on 23/07/2021 12:21:06

Hi Nick

Contact a precious metal refiner.

Tell them the weight, anticipated silver content and the presence of cadmium.

Historically they would offer 90% of the silver value less a refining fee. Payment would be within 48 hours of analysis.

Google "Metal Refiners UK"

Keith

I use AWA refiners for my precious metal scrap. Mine is mostly electronic but they do everything. Always had fair prices from them.

https://www.awarefiners.co.uk/precious-metals.php

Robert G8RPI.

Hi Keith, thanks for your answer, however all I know is they are silver solder rods, no idea what the silver content is or any thing else and I haven't used any of them since I've had them, but a refiner may be an option and I'm not really bothered about their value, they were a "might come in handy" thing at the time.

Regards Nick.

Keith did you question the supplier about the legality of what he is selling? Would be interested in what he said.

I'm presuming the answer to Jason's question is a 'yes' as the webpage with said product has been taken down.

On a broader point regarding Cadmium content, I use quite a lot of Aerospace fasteners in my hobby, these are often Cadmium plated. I also wonder at what compliance issues there may be with substituting modern silver solder on fittings etc. for aircraft where an Easy-Flow solder would have been originally specified. I wouldn't be surprised to find that it's similar to the AVGAS situation where Tetra ethyl lead is present in abundance in our 'lead-free' world.

Anyone seen a warning about abusing cadmium plated bolts - heating to remove a stubborn nut / bolt etc ?

I have a goodly stock of cadmium bearing silver solder. I only work outside and use a positive pressure breathing apparatus.I believe this is safety enough. If it isn't, then at my advanced years, I am not unduly bothered,

Andrew.

I used to work in the areospace industry and I doubt very much that subtitution would be allowed by CAA or Mod.

If the aircraft was certified as airworthy and had EasiFlo 2 on it's certificate then that is what must be used.

I came across quite a bit of this in my job e.g.:

A new throttlebox was ordered for a Canberra and it turned out that the plastic handles were made by Raleigh for a kiddies tricycle. It took months to find some and then a box full turned up in an almost forgotten toyshop in Grimsby that had closed years before.

We had an order to make a new pilots seat for an ME 109, fortunately, exactly the same specification aluminium alloy was still available.

It doesn't matter that a better, modern material to a different spec might be available, if it's not covered by the airworthiness cert. then it can't be used.

Brian

Edited By Brian H on 23/07/2021 16:49:34

I also worked in the aerospace industry and have experience of material changes.

If a material becomes obsolete and is no longer available (such as Immaculate 5 stainless steel) a substitute has to be found. The procedure in the company I worked for (I guess it was industry wide) was that a Design Alteration Reqest would be raised and all the experts (service, design, manufacture, lab and specialists engineers) and others would study this in great depth. The DAR, which had the highest priority, was usually accompanied by a big person, usually male, responsible only to the chief engineer. He would not go away until you had agreed to the request or turned it down. Sometimes the process took a couple of weeks, sometimes months. Once the DAR was accepted the part would be re-standardized. This cost a lot of money and there were always customers waiting.

This was done for all changes, not just materials.

JA

Edited By JA on 23/07/2021 18:03:39