Member postings for Keith Hale

Hi Dave,

Pleased to have been of help. It's part of the package of being a customer of CuP Alloys.

Keith

Hi Dave,

Silver brazing alloys do not respond any differently with german silver be it old or new!

They will respond to the composition of the parent material. It will behave differently if there is any lead present. Alter your technique to compensate for any lead to improve your chances of success.

Good luck with the idea that trying to make the joint quicker will alleviateany problems the lead may create. Expect more trouble!

Keith

As far as I am aware, the the "new tippex" is water based and is safe.

What did Johnson Matthey say about the composition and availability of their product?

Keith

Hi All,

Sorry it's got to be said, This includes my book discounted 15%ish

"Guide to Brazing and Soldering"

"Everything you wanted to know but were afraid to ask"

Regards

Stay safe

Keith

And if you want to see how to use it visit the website **LINK**

Select "Other Silver Solder"

Scroll down to "Technoweld"

"View Product" for details of a link to 6 video clips

£40 per metre ? More like £16.

Even less this week for TELEPHONE orders.

Keith

PS My book is available at £15 instead of £17.95 this week - again only for TELEPHONE orders

Hi All,

An advantage to be gained from the aggravation of telephoning your order through during, what was to be, the "Exhibition Period" is an element of "one2one" contact.

While ordering, there is the opportunity to discuss any problems you may be experiencing or information required. It is within the capability of the model to overcome any difficulty. There is the opportunity to determine where you are deviating from the basic principles of the process for the difficulty to arise. And for that we need conversation.

All the information you may require and lower prices.

Win win situation.

Keith

Hi Bill,

The vast majority of brazed joints between two steel components are made using a brass filler metal. The reasons are clear. The joints are strong and the filler metal is cheap. Why use anything else?

In all cases, you would change to a silver solder only to satisfy a technical issue eg colour match, dissimilar component materials, to reduce distortion by making the joints at a lower temperature. Another possibility is that your heat source won't deliver enough heat.

In the last case, the first option is to fit a bigger burner. Such a burner does not have a higher flame temperature but does burn more gas and as such develops more heat. Bullfinch will tell you the heat rating of your existing burner.

The higher flame temperature of oxy-gas flames does not always generate more heat.

The flame profile often pushes the user to adopt a welding technique that will lead to a lack of penetration of the filler into the gap and a weak joint.

So, in a nutshell, the cheapest option would appear to be, stick with the brass rod and simply fit a bigger propane burner. (What? - this guy sells silver solders!)

No good? Either buy a new/different torch generating more heat (not forgetting to amend your heating technique it's easy enough but needs to be done)

Alternatively buy some silver solder but only use it where necessary. As before make sure you use an appropriate flux.

You pay your money and take your pick!

Keith

PS The cheapest joints are not made using the cheapest silver solder. (But I would say that wouldn't I?) But that's another topic!

Edited By CuP Alloys 1 on 22/04/2020 08:30:16

Hi.

I am confused!

The link seems to tell me that the potential problem occurs at temperatures in excess of 1000 deg C not 600 deg C. At 1000 deg C, most of the components being assembled by the model engineer will have melted or are on the point of melting! Such a temperature does not relate to using a silver brazing alloy although it might at a push relate to overheating a copper-zinc brazing alloy. Beware of boiling off the zinc.

The link also seems to tell me that the potential problem stems from prolonged heating in kilns and furnaces (years). Most brazed joints are completed in minutes.

But the link also seems to tell me that there are no special precautions relating to the transportation and storage of the blanket. My experience of stockist warehouses bears that out.

But although the model engineer may use it but he doesn't handle it. Any irritation is negated by common sense and adopting good brazing practice. Wear gloves - marigolds (other makes available!) That statement lies alongside recommending that you don't pick up the brazing rod by the hot end.

But more seriously. Steel takes longer to heat up and if the alloy doesn't flow consider changing the flux to one with a longer life. Alternatively consider reducing the brazing temperature and time by using a silver brazing alloy. Your choice.

A Sievert torch has a very wide range of heating capability. It's ideal for the amateur model engineer. I've got one myself! It will give you what you need.

As ever, if you want any information regarding the brazing process, materials or equipment then give my colleagues at CuP Alloys a call.

Keith

Hi Robin,

See personal message.

Keith

Hi Robin,

Can't help but wonder what your supplier suggested?

Your item is not going to be hallmarked so why use a hallmarking grade of silver solder?

Why not use a more readily available alloy with 55% silver as opposed to the 67% and with a lower melting point and cheaper?

When I worked as a Technical Sales Rep for Johnson Matthey Metals we made bi-metal sheet and strip by hot rolling fine silver 99.95% into a groove cut into the brass. The resultant slab was then rolled to the finished required thickness.

So your hot working technique could work.

Fine silver will work harden, but it will anneal at relatively low temperature. Keep it on a domestic radiator long enough will anneal it!

Do Cookson sell fine silver wire?

Got any silver fuse wire?

Know any electroplaters that might cut you a sliver from an anode?

Will your local MANUFACTURING jewellery company or bullion dealer provide you with a lead? Forget the high street.

You could always ask Johnson Matthey!

If you opt to go down the brazing route consider using a paste containing flux and filler metal in the bottom of the groove. Lay the circle on the top. Heat as suggested by Bill, from underneath.

Declaration of interest - like the information you can get the paste from CuP Alloys!

Hi Adrian,

And thanks to Bill.

With one eye on the Antiques Roadshow!

if you bought the torch kit from CuP, you already have a bigger burner generating 7kw of heat.

If you didn't, then you have a choice. Buy a bigger burner or improve your chances of success by insulating the joint better with an insulating blanket. Readily available from CuP.

No reason why you shouldn't be able to make all the joints with 455.

Regards

Keith

Declaration of interest - despite retiring 7 years ago, I'm still on their books!

Hi Adrian,

A question I often ask, Why didn't you ask your supplier of equipment and silver solder?

They are not a company that simply takes your money and leave you to get on with it. You can draw on the 100+ years of collective experience to help.

A couple of years or so ago, they were demonstrating with the help of Western Steam, the building of a similar boiler at the Midlands exhibition.

Who knows. As a customer, their technical support is included in the price of the silver solder.

Regards

Keith

Hi Rowan.

Correct!

Keith

Hi David.

Thanks for the note and apologize for the blip.

I don't know what the problem is, but I will inform Glenn and Shaun today.

Can I suggest that you give them a call tomorrow?

Regards

Keith.

Hi Rowan.

Check your personal messages. The chances are that your brazing alloy contains a significant amount of zinc!

Or email your phone number and I will ring you.

Regards

Keith

Hi Rowan

As I understand it, you are not welding. You are brazing with a "silver solder". Big difference!

See p.m.

I am not about to turn down my heating nor dispose of (responsibly) all the brass in my home and workshop!

Hi David,

455 would be fine. It produces small neat joints.

Regards

Keith

Hi David,

Make a solder ring to fit inside the fitting. Probably using 1.0mm wire

Flux the joint.

Heat the joint line, the alloy will melt and flow towards the heat.

If using paste, put it inside the fitting and heat as above.

If using paste, you will probably need twice the amount you think!

A ring is the cheapest option.

Regards

Keith

Hi Martin,

I didn't pay£250 and got it surprisingly easily from the internet at no charge.

A "downloadable" version is available. Set your printer to double sided printing and load 25 sheets l!

Personally, a better option is to buy my book, which is based on this BS and costs considerably less. Regrettably, it is not available from any reputable book shop! It is available from CuP Alloys.

Keith

PS you can also download some of the detail from CuP Alloys website. Free!

If the lead content exceeds 2%, it can affect the brazing operation.

It can form an unwettable dross at the interface.

It can cause cracking.

These effects can be reduced by adequate fluxing and uniform heating without imposed stress.

Source of information - BS EN 14324:2004 Section 5.1.2.8

This document would be of great interest to the model engineer. It defines the process. Silver soldering is part of the brazing process. Silver solders, conforming to BS EN 1044, as used by model engineers, are referred to as silver brazing alloys. Brazed joints can be made with copper, silver, nickel, gold, palladium and aluminium alloys.

It offers guidance on joint design and heating techniques.

Download it

If the model engineer reads and understands this document, he will produce stronger, neater, cheaper joints. Brazing is a simple process, made difficult by not sticking to the basic principles. It is a skillful process, but this document will highlight where to develop your skills. Then, it's practice, practice.

Keith