Author Topic: Silver solder info  (Read 3421 times)

Offline Stuart

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Silver solder info
« on: August 14, 2012, 02:55:18 PM »
Guy/Gals

I have received this info via email from one of the UK alloy providers to the modelling fraternity



MODEL ENGINEERING.
Of all the people that did not stock up with cadmium bearing silver solder at the end of 2011, most seem to have adjusted to using the cadmium free alloys. Of course, these alloys do not flow as readily as AG303, but they aren't bad! just a little different!
Are you struggling?
Consider opening up your joint gaps slightly, say to 0.15mm.
Fit a bigger burner to decrease the time getting the alloy liquid.
Use a thinner rod.
Follow the basic principles and you will still get full penetration of the alloy and produce strong, leak free joints.

Professional boiler makers and some amateurs are telling us they now actually prefer the cadmium free alloys. 455 (55% silver cadmium free) is not as fluid enabling them to control the flow easier, and as a result, are using less of it.
The environment in the firebox is particularly aggressive. 455 gives better corrosion resistance to the joint to prolong boiler life.


Tricks of the Trade - Joining Alumiunium.
Soldering aluminium successfully depends on removing the oxide layer on the surface. That means using a suitably aggressive flux. Use our Stayclean Aluminium Flux with any soft solder including 60/40 tin/lead.
Stayclean Aluminium Flux is available in 125ml pots with an applicator brush cap.
For a better colour match use our 2207, a low temperature white alloy containing silver and tin.
Both alloys are available in 0.5 kilo reels or by the metre in 1.0 and 1.5mm dia.

Aluminium Bronze is often used for it's machining qualities, but can be difficult to silver solder. The alloy melts, goes into a ball and falls on your slippers! This is a fluxing problem. Add 25% by weight of kitchen salt to your conventional silver solder flux, for example our EF Flux. The extra chloride ions will remove the aluminium oxide - problem solved!


Note I have no connection with this firm


Stuart
My aim is for a accurate part with a good finish

Offline spuddevans

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Re: Silver solder info
« Reply #1 on: August 14, 2012, 03:34:20 PM »
Some helpful info there, thanks Stuart :ThumbsUp:  :pinkelephant: :ThumbsUp:


Tim
Measure with a Micrometer, mark with chalk, cut with an axe. MI0TME

Offline Jo

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Re: Silver solder info
« Reply #2 on: August 14, 2012, 03:48:17 PM »
Polly Models in the UK have put up some really useful guidance on using these new silver solders here:

http://www.pollymodelengineering.co.uk/global/technical-notes/basic-silver-soldering.asp

Jo
Usus est optimum magister

Offline Jo

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Re: Silver solder info
« Reply #3 on: August 14, 2012, 03:55:20 PM »
I disagree with Andy's (Polly Models) comment on cleaning up flux residue  :disagree:.  Citric acid crystals is best brought from home brew shops last time I paid about ?1 for 500g of crystals (for making home brew of course :DrinkPint:).

I personally still use sulphuric acid as a lovely man gave me a carboy full of 95%+ concentrated :stir:.

Jo
Usus est optimum magister

Bogstandard

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Re: Silver solder info
« Reply #4 on: August 14, 2012, 04:39:42 PM »
Very good info there, both from Stuart and Jo. :NotWorthy: :NotWorthy:

This is the sort of information that is useful to almost anyone, and is most welcome here.

John


Offline Stuart

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Re: Silver solder info
« Reply #5 on: August 14, 2012, 05:06:42 PM »
Thanks for the comments

Stuart
My aim is for a accurate part with a good finish