Member postings for shaun meakin 1

Hi Chris,

it sounds like you have overheated the flux. A flux is like a sponge absorbing oxide as well as creating a barrier to further oxides forming. After a while, like a sponge, it can become 'saturated'. Plus if you get above the working temperature of the flux it will 'bake' on leaving a glassy hard residue difficult to remove. This is especially true if the joint takes a long time to reach brazing temperature. In future please consider a flux with a longer working life, for example our HT5.

Hope that is of interest.

\Shaun.

The National Model Engineering Exhibition 2023 and Harrogate Model Rail two fantastic events with just one admission ticket apparently. March 10th 10am-7pm and 11th 10am-5pm. We (CuP) have expressed an interest but at this time we have no further information re costs etc. It is 2 days only.

Noel et al are right! After 2 years or more of Exhibition wilderness we must try and return to some normality and supprt these events. CuP Alloys will be there as before. One way of looking at it is that there are discounts to be had and these will go towards the cost of attending. For the beginner there is a wealth of experience and advice to be had, if only from Noel!! This might save a very expensive mistake in the future? These are just a few of the reasons why the hobby should rally round and support these events wherever possible.

We sell flux paste in 250gr and 500gr containers please see https://www.cupalloys.co.uk/store/EF-Flux-Paste-250g-p276411631

Jason B is correct we also sell 455 as a paste including flux.

If you are to dip the rod in the flux, known as 'hot rodding' please only do this to add flux during the brazing operation. As soon as you heat the bare metal it will oxidise, pre placing flux acts as a barrier.

If you have flux powder we recommend mixing it into a paste with water and a few drops of washing up liquid. The detergent helps keep the powder in suspension, it also acts as an extra degreaser and if the flux goes hard it will remix with water and a few more drops of washing up liquid.

I hope that helps but as always we are at the end of a telephone for help and advice where necessary. - Shaun.

Im don't like to advertise on the forums but if anyone looking for suggestions for reading matter, how about Keith Hale's book A Guide to Brazing and Soldering?

It can be found at https://www.cupalloys.co.uk/store/A-Guide-To-Brazing-And-Soldering-by-Keith-Hale-p276411652

Hello Maarten and everyone from the wonderful Nederlands. CuP are hoping to be at the Stoomgruip Zuid early next year restrictions allowing. I usually try and link it with watching SC Heerenveen. Hopefully some of you can come along and say hi.

We supply vermiculite blocks which are lightweight and reflect the heat back into the brazing area. Anything that helps speed up the time taken to get the joint up to brazing temperature is good practice.

They can be bought individually or as a set with a kaolin wool mat. As an optional extra we supply a laser cut frame for them to fit in.

The kaolin blanket in itself is a good insulation material. If wetted it can be shaped and when dry will retain that shape. In the olden days we used to put a bit of the mat on our hand and heat a piece of copper up to cherry red. Not allowed now of course!!

If you are going to the Midlands (fingers crossed) they are 25% cheaper than on the internet.

Shaun.

Just completed the booking form and returned with payment. Cannot wait!!!

Anyone spot my deliberate mistake? It's the 2942 burner that produces 26Kw.

Hi Peter, some good advice here. It is true the heat comes from the amount of gas burnt. The Sievert torch kit we sell comes with the 2941 burner producing 7.7Kw of heat. By changing your burner to 2941 you go up to 26Kw. There are a couple of bigger burners available, please ensure you have a long neck tube as it gets hot!! On the website www.cupalloys.co.uk we have a small video showing the flame profiles of a few burners. As Andrew says it is common practice to use the propane torch to get near to brazing temperature and then use a more precise torch, eg oxy/acetylene or oxy/mapp.

Hope this is of use.

Shaun.

Hi Eckart, CuP can supply 500gr reels both flux cored and solid. We call it CuPSol but it is only a rose by another name. Please call for a price. However, I must say I agree with the majority on here, silver solder would be my recommended method.

It's a minefield out there guys, and appears to be getting worse. Saw on Twitter yesterday some young person had 3 accounts cleared out (including up to her overdraft limit) plus their ISA with this redelivery scam. When I think of some of my elderly relatives and friends who could innocently fall for something like this it makes my blood boil!

I have seen on social media that a new scam is around where you are asked to make a payment to Royal Mail for redelivery of your parcel. THIS IS A SCAM - ROYAL MAIL DO NOT CHARGE FOR REDELIVERY.

We at CuP Alloys rely heavily on our wonderful mail system, please beware. Any problems, worries or questions please do not hesitate to contact us.

Thanks Michael, much appreciated.

After 10 years of sterling service by the old website, CuP Alloys have launched their new, modern, up to date and mobile device friendly site.

The address is still the same www.cupalloys.co.uk so no need to change anything if we are in your favourites and it contains all the usual benefits of hints, tips and advice for the Model Engineer as well as the 'shop' for competitively priced high quality brazing and soldering materials and equipment.

We have sections on 'Best Brazing Practice' **LINK** offering advice to avoid common mistakes. Advice re joint design, heating techniques, fluxing etc helping the Model Engineer to achieve sound, leak free joints. Want to join stainless, brass etc see **LINK**

Still not 100% confident with your brazing technique? There is a video clip showing the basic brazing principles in action. **LINK**

Wondering which burner will provide the right heat for your joints? There is also a video clip showing different Sievert burner profiles.

Everything the Model Engineer needs when soft soldering or silver brazing.

Of course if you cannot see what you need we are as always on the end of the telephone for sound, impartial advice.

Hi Bazyle, CuP Alloys have for many years presented a talk to clubs and societies on brazing and soldering. It is something we have offered via zoom (for a smaller fee as we obviously wouldn't have any travelling expenses.)

As an example please see https://www.cupalloys.co.uk/society-presentations/

We could also offer sales of products via card payment after the talk at discounted prices, preferably sent to the club for collection from there.

If anyone is interested or would like to discuss options further please give me a call.

Shaun 01623 707955.

Hi Howard, brazed stainless and water are not a great mix. The joints can suffer from what is known as 'crevice corrosion' something no one has really been able to explain. Nickel bearing stainless such as the 300 range are more resistant to this so 304 should be ok. Just a word of caution.

Thanks for the referral David. Al it is something we are considering, offering starter 'packages'. If you would like to contact us we would put something together for you. Cheers, [email protected]

Hi John, the key to joining stainless is the flux. When heated in air chromium oxides form which are very difficult to remove. I am afraid I wouldn't recommend either of those fluxes. I have to declare an interest as being from CuP Alloys, but we supply Stayclean soldering flux for stainless. Unfortunately this product cannot be sent via Royal mail so is quite expensive to cover the carriage charge.

It's an interesting topic. In truth apart from expensive analysis at for example the Assay Office it will be very difficult to determine. Melt tests are fine for showing if an alloy melts at a lower/higher temperature than another but this is not necessarily an indication of the make up of the alloy. I am not a model engineer but I don't think this test would pass for a boiler inspector should that be your aim.