S05 Dencon Lead-free solder,melting point?

essdee
Posts: 376
Joined: Sat Nov 29, 2008 4:47 pm

S05 Dencon Lead-free solder,melting point?

Postby essdee » Fri Mar 02, 2018 5:41 pm

In Googling, I have failed to find a reference to the melting point of this Sn-0.75Cu lead-free solder, which has been lurking in the armoury a fair while. I think it was a Maplin's job, coiled in a tube with a green cap.

As I await a long-delayed Squires order, and my supply of 222deg solder dwindles, can anyone confirm if this Dencon stuff has a similar, 'high' melting point, please.

Many thanks,

Steve

jasp
Posts: 98
Joined: Thu Dec 04, 2008 9:24 am

Re: S05 Dencon Lead-free solder,melting point?

Postby jasp » Sat Mar 03, 2018 11:02 am

Hi Steve
Lead-free solders, generally, have a higher melting temperature than the lead-containing.
Why not try a wee experiment?
Find where on the dial of your soldering iron the 222deg. solder melts and then try the Dencon.
A bit crude but will give a relative assessment of the melting points.
Jim P

essdee
Posts: 376
Joined: Sat Nov 29, 2008 4:47 pm

Re: S05 Dencon Lead-free solder,melting point?

Postby essdee » Sat Mar 03, 2018 2:48 pm

Thanks Jim - simple but brilliant...

Will do!

Cheers,

Steve

JFS
Posts: 659
Joined: Wed Dec 16, 2009 3:47 pm

Re: S05 Dencon Lead-free solder,melting point?

Postby JFS » Sat Mar 03, 2018 5:13 pm

essdee wrote:In Googling, I have failed to find a reference to the melting point of this Sn-0.75Cu lead-free solder, which has been lurking in the armoury a fair while. I think it was a Maplin's job, coiled in a tube with a green cap.

As I await a long-delayed Squires order, and my supply of 222deg solder dwindles, can anyone confirm if this Dencon stuff has a similar, 'high' melting point, please.

Many thanks,

Steve


Hi Steve, if it contains no silver, it will be 227deg.C. (Edit:- Sn99.3 Cu0.7 eutectic temperature) If it does contain silver it will be 222deg. Needless to say, the cheap stuff contains no silver! In my opinion the 227 stuff is useful for soldering water pipes, but useless for our purposes as its melting point is too high and its flow and wetting properties are pretty poor. The silver bearing stuff is better but not brilliant.

Is there a reason to need such a high MP? f not, I would use a Tin-lead-silver 179deg solder - pricey, works like a charm! I always smile when people on other forums discuss endlessly how to "solder so cleanly" without ever discussing the type of solder - there is million miles between 188 deg solder and 179 deg solder in terms of the quality of results they produce!

Best wishes,

Howard

essdee
Posts: 376
Joined: Sat Nov 29, 2008 4:47 pm

Re: S05 Dencon Lead-free solder,melting point?

Postby essdee » Sun Mar 04, 2018 11:14 am

Thanks for the detail Howard, it is indeed Ag-free. Made in Taiwan, I note.

I gather from Squires that my order is now on the way at last, one of a 'surge' sent out this last week (?!), including a replacement for my dwindling tube. The Dencon stuiff does now sound as if it will be a stand-by at least.

For the last ten years my loco builds have used: 296/222/188/145/100 and 70 degree solders where appropriate. The 222 is handy for assembling the larger sub-assemblies where the 296 will not flow, and gives a larger 'safety' reserve when subsequently employing the 188.

I was staggered at the range of specialist solders available, when I Googled. Predictably, the lengthy table did not include my Sn-0.75Cu recipe.......

I will also have a play with that 179 recipe you quite, sounds interesting!

Thanks again for the 'gen',

Best wishes,

Steve

JFS
Posts: 659
Joined: Wed Dec 16, 2009 3:47 pm

Re: S05 Dencon Lead-free solder,melting point?

Postby JFS » Sun Mar 04, 2018 6:49 pm

You are welcome Steve. I was a bit surprised that you did not find the Sn Cu 0.75 - this is the most common "lead free" solder. I would not want to teach you to suck eggs if you are a metalurgist (which I am not!) but this is a "Eutectic" alloy which means that this is the lowest possible melting point of any possible combination of Tin/Copper - bearing in mind that these are "bronzes" so at the high copper varieties we use them as bearings, balve bodies etc!

There are in deed many types of solder and the electronics industry has done a lot of work to understand solders and dev elop lots of possible alloys for the job.

It seems you use "differential temperatures" for soldering, which is a good reason for using a higher mp solder - but for me, the kay is the addition of the silver. Is adds a fair bit to the price, but for ease of use it is worth every penny as we use so little. So the Sn/Cu/Ag 221 and the Sn/Pb?Ag 179 are pretty good for this purpose. Can't say I have used the 145 though I did hear that it can tend to brittleness so I would be interested to hear other people's experience - though brittleness will only show up where a joint is subject to stress reversals - which the average boiler band is not!.

One thing that most people are not aware of is that a non-eutectic alloy does not melt at a single temperature - rather, it starts to melt at one temperature but will not be fully liquid until a higher temperature. For some applications, this "pasty range" is very useful - it is how plumbers "wipe" a joint in a lead pipe. But for our kind of jobs it is an infernal niusance - unless that is, you want to "fill" a flair on a tender, or make a radius on a Belpaire firebox - in which cases it is ideal!.

Best wishes,

essdee
Posts: 376
Joined: Sat Nov 29, 2008 4:47 pm

Re: S05 Dencon Lead-free solder,melting point?

Postby essdee » Mon Mar 05, 2018 9:35 am

Hi Howard,

I had to smile at your reference to eutectic alloys! In fact I had a fair bit to do with multi-element phase diagrams as a geology student - but nothing to do with them in six years as a research metallurgist! (I transferred electron microscopy/microanalysis skills between disciplines).

Er, and do I detect the signs of an extremely useful short (?) article on solder types for Editortim - I suspect it might be widely welcomed?

Best wishes,

Steve

JFS
Posts: 659
Joined: Wed Dec 16, 2009 3:47 pm

Re: S05 Dencon Lead-free solder,melting point?

Postby JFS » Mon Mar 05, 2018 10:04 am

Ah - I thought you might know more than you were letting on!! As for an article, I suspect there are those who know far more about the job than I do! But I agree that such a thing is needed - I never cease to be amazed at just how many ways modellers find to make soldering difficult!

Fluxes are another bag of unknowns - Tony WIlkins and I recently did a bit of investigation into stainless steel rail (which I think, despite challenges, has a lot of promise) and it brought me into contact with "Carr's Brown Flux". Having previously seen it described as "Nasty stuff", I approached the job with trepidation, but I found it remarkably benign. Indeed, I have just been doing some soldering of piano wire and found it much more effective and easier to use than phosphoric acid. Trouble is, I have no idea what the stuff is - there seems to be no "data sheet" - just a statement that it is "strong acid". I really do not like being in the dark - what if I have an accident with the stuff? So what is it? Anyone? Answers on a postcard please...

Best wishes,


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