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[dave greenhamParticipant @davegreenham19379]

Hi Guys

Is there anyone out there thats local to Sileby Loughborough ?

I keep being told that silver soldering is easy ( yeah right ) I can't seem to do it to save my life. everything is clean, I've tried the flux both thick and thin but nothing seems to work, it just wont run . If enyone is local and would be willing to come and show me what I'm doing wrong that would be great . Transport is not a problem I can pick you up and return you to home. Its driving me mad and I'm useing so much solder but getting nowhere fast. I'm at home 99% of the time so anytime of day is fine for me .

Very many thanks

Dave Greenham

 

Edited By dave greenham on 17/11/2012 09:14:36

[dave greenhamParticipant @davegreenham19379]

Silver soldering

[TerrydParticipant @terryd72465]

Hi Davis,

See your private messages

Best regards

Terry

[nigel jones 5Participant @nigeljones5]

hi dave

this is most odd…its a very easy process unless youe doing multiple tubes in a confined space…please tell me what rod you are using, what flux, what material, what the job is and how u are heating it…

[JasonBModerator @jasonb]

And what you are heating with, sounds like you are melting teh solder on teh surface but teh base metal is not hot enough for it to flow.

J

[dave greenhamParticipant @davegreenham19379]

Hi jason

i'm using a machine mart blow lamp running on a large propane cylinder

dave

[Jeff DaymanParticipant @jeffdayman43397]

I agree with Jason, it sounds like a heat issue. Some photos of the workpiece and the torch would help.

Is your torch a normal short plumbers one with tiny air holes around the base or is it the type with a large long tube about 16mm dia and 4 air mixing holes about 5 mm in dia near the base? The small type will only work for very small silver solder jobs, if at all for silver solder.

You do need far more heat for silver solder than for soft solder, and the bigger lump you are soldering the more heat you need.

If you can find some firebrick you can place them loose in a table shape with vertical walls behind, and silver solder the article in the resulting firebrick nest/hearth. This will concentrate the heat better.

Are you anywhere near Chesterfield? Keith Hale at 'CuP Alloys' there carries a full range of suitable torches and solder and writes in this forum frequently to help folks with soldering issues. If you took your job around to him I imagine you would get it sorted out quickly.

JD

[DAVID POWELL 4Participant @davidpowell4]

Dave, had exactly the same problem when making a 3'5 inch boiler for Juliet.>>

Practicing on 6 " strips of copper with the yellow gas bottle from B and Q worked a treat. BUT when using it on the boiler the heat would quickly dissipate and there was no way I could get the temp up.>>

Tried those small gas bottles from Cup alloys, no good. Spoke to 2 of the professional boiler makers who attend the shows and they both said the same thing. They blast the boiler with a big sievert then dive in with oxy/acetylene. Now the oxy set up is very expensive for the casual user but I found an alternative which is Mapp gas and oxygen from CWB's in Caldicot, near lace w:st=”on”>Newportlace>. Once you buy the setup circa £250 you simply pay to fill/replace the bottles about £15 each. No rental costs.>>

Using this setup and the biggest nozzle I now blast the boiler with the Sievert and dive in with the Mapp/oxy. So far it works fine. Bigger boiler may be more problematic and I am thinking of building a 'proper' grate and possibly have a gas ring(s) underneath to give a constant heat supply. Anybody got any thoughts on that?>>

[TerrydParticipant @terryd72465]

Hi Dave,

Have sent another message,

Best regards

Terry

[shaun meakinParticipant @shaunmeakin78815]

Hi David, firstly i feel i must declare I work for CuP Alloys Limited but I am not trying to advertise. The guys I think are right, you have a heating problem. This is very common, particularly since the ban on the cadmoim alloys as the cadmium free ones do need a bit more heat. Although you may still have the cadmium alloy. Propane is a more than suitable gas as long as you have a big enough burner on the other end. Sievert have burners from 0.25kw/hr right upto 86 kw/hr all of which fit on their pmpx torch kit. the kit will cost approx £94 inc vat and delivery. Jeff gives good advice about insulation, but if I may say firebricks do absorb heat and you might be better with kaolin wool. As I said I''m not wishing to advertise but there are lots of tips and information available on our website http://www.cupalloys.co.uk please feel free to peruse.

Silver soldering really is not that difficut if you get the piece clean, put on enough flux and apply enough heat. I am technical, not practical (often in danger of picking the rod up by the hot end!!!) but even I have silver soldered successfully!

I hope that with the other advice helps solve your problem and I have not broken any rules by mentioning my employment!

[dave greenhamParticipant @davegreenham19379]

Hi Everyone

Wow, so much advise. This is great, thank you all very much. Terryd has kindly offered to come over to try and sort me out tomorrow and I'm looking forward to it , as at 65 i need to retain as much hair as i can ( it gets cold in the garage lol )

once again thank you all very much

Dave greenham

[Ian S CParticipant @iansc]

Shaun, so you pick up the cold end, bend one end into a hook shape, and heat the other end. You can hang the rod on something to store it. Ian S C

[nigel jones 5Participant @nigeljones5]

as an aprentice, some 27 years back I too picked the rod up hot end first, then scratched my forhead with it. Itch went but still got the hole where the rod seared into my flesh! Not done it again since!

[dave greenhamParticipant @davegreenham19379]

Hi Guys

update…

Terry came yesterday as promised and after the compulsory cup of tea

we went into the workshop for a demo. Terry had brought his own little hearth

as he knew I was using vermiculite blocks. He explained why the are not as good as fire bricks and showed us the difference ( vermiculite hold the heat more than reflect it )

anyway, he set his hearth up and off he went with the demo. explaining what he was doing as he went.

Yep, Silver soldering is eeeeazy. where was I going wrong ? as a lot of you pointed out. heat ( not enough off ) vermiculite blocks tend to hold heat more than reflect it. the joint not clean enough, but to be fair, some of the muck was exhausted flux. and finally the shape of the hearth. So. Today Ive been out there and made my first good silver solder joint YAY.

Very many thanks Terryd and all of you for your advise.

Dave Greenham.

[TerrydParticipant @terryd72465]

Glad to be of help Dave, and thanks for the tea – hope your boiler turns out as well as I think it should. And get Bob working as well . I assume it didn't take as long this time to get a good joint!!

Best regards

T

[JasonBModerator @jasonb]

Good to hear you have got thing ssorted Dave, now just remember no more silver steel stays and you will be OK

J

[dave greenhamParticipant @davegreenham19379]

Hi Jason

LOL you live and learn . I wonder how many other things I'm doing wrong

[NJHParticipant @njh]

Hi Guys

My problem is just the opposite of Daves – how do I ensure that silver solder will NOT run.

I have a brass assembly to silver solder together in which there are some 8BA steel studs. If the solder runs into the exposed threads I will not be able to re- thread them as they are too close together. It is not an option either to drill and tap after soldering. "Plumbers Black" used to work for soft solder anything similar you can recommend for silver ?

Regards

Norman

[KWILParticipant @kwil]

Soft pencil rings around the area to be protected and/or Tippex (or similar correcting fluid) on threads. I was told limewash also works but have not tried it. Keep the flux away so that the brass oxidises where you do not want the silver solder.

[JasonBModerator @jasonb]

As KWIL says Tippex will stop teh solder sticking, you can see it here being used to stop the part sticking to the jig, spacers and to pegs to locate the bosses.

Chuck the lot in pickle and it comes out like this

[David Clark 13Participant @davidclark13]

How about using some aluminium screws, bolts or plugs.

Silver solder should not stick to the aluminium.

I doubt the aluminium would melt at silver soldering temperatures.

regards David

[JasonBModerator @jasonb]

It does, don't ask how I know.

Easyflow is about 620deg, Cad free 55% is 630-660deg. Melting point of aluminium 660deg so there is not much leaway.

J

[Jeff DaymanParticipant @jeffdayman43397]

I doubt the aluminium would melt at silver soldering temperatures.

regards David

Sorry, that is not correct, alum will melt at the high end of silver solder temps, especially small sections of alum.

JD

[TerrydParticipant @terryd72465]

Hi,

There are various 'resists' to prevent flux and hence silver solder flowing. A I showed the OP Tippex works well (as Jason shows) also lead pencil (graphite) as well as a past of jewellers rouge and even loam will work. The main job of the resists is to prevent the flux spreading and there is no flux the solder will not flow. More than one way to skin a cat!

Best regards

T

[NJHParticipant @njh]

Thanks all

Tippex and lead pencil it is then.

I guess this could be one instance of Tippex correcting mistakes BEFORE they occur!

Cheers

Norman

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