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Plumbing using hard solder


Ralph
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I have just been browsing through some old postings re. plumbing and will have to admit to being one of the burks Opel Fruit referred to for using UK soft solder. So for when I return to our house at the end of the month and clear up any resultant floods, can someone give me advice on the following.

1. Is hard solder used with the same flux as UK soft solder?

2. Am I right in thinking that I will need to buy a hotter gas torch than the small butane/propane mix plumbers torch that I have used so far? If so any advice on type/make?

3. Does this hard solder have the same appearance as soft solder, in other words is it a roll of 'wire', or a stick?

4. When remaking my soft solder joints, will it be sufficient to melt the solder out of the old joints, re-flux them and then flow new hard solder into the joints, or do I need to replace them all?

Any other advice on using hard solder would be appreciated - it's a whole new adventure for me!!

Ralph

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The flux is largely the same though formulated for a higher working temperature, but to answer two questions in one, you can buy hard solder wire (2mm) which also has a flux in it. Flux is called decapante in France. Buy a small reel. And check whether it does have flux in it or not!!

Do not use additional flux, it will catch fire and blacken the pipe making soldering "difficult". Fry's flux and the like from the UK will NOT do.

Butane torches are fine.

You need to completely replace all your previous soldered joints to ensure you don't end up pumping solder into the pipe and partially blocking it. Try if you like! You should be OK to heat and remove the old ones and leave the tinned copper ends of the pipe as is.

Remember that ANY water in the joints will ruin a resolder joint.

I assume you are doing this on mains pipes, not heating pipes. Heating pipes can be left as they are.

Hard solder is used because it is lead free and therefore "potable" (and legal), and forms a much stronger alloyed joint than lead/tin soft solder.

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Lead-free soft solder isn't quite the same in terms of characteristics. In particular, it melts at a higher temperature than 60/40 lead/tin. (Don't confuse "Fusion" with melting point). If you were to use a temperature controlled soldering iron with a Curie bit calibrated for 60/40 lead/tin or 63/37 lead/tin and tried to successfully flow lead-free soft solder, it wouldn't work.

From a potability point of view, any lead-free would do. From a pressure/frost resistance point, hard solder is preferred.

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Opel fruit

With regards to the great debate here on solders. If the installer has used the standard for example BS 29453(yes I know I have quoted a BS ref) lead free solder with a melting point around 227 deg C and able to withstand pressures of 50 barG on a soldered joint for copper what is the problem?

This would be the standard reel 500 gm and 3.2 wire.

This does not include flux and joints would be cleaned and fluxed accordingly.

Please advise if I have missed something as always keen to know and shared knowledge is a fine thing.

To the person looking to redo the joints I would first check on the spec of the solder you used before undoing all your joints,tees etc as you may be making yourself unnecessary work. unless OP has info to the contrary

Just for reference

All lead-free alloys melt at a higher temperature than traditional tin-lead alloys. when using lead-free materials. Typical melting points:

Tin-Copper 227°c

Tin-Silver 221°c

Tin-Silver-Copper 217°c

Tin-Silver-Bismuth 205°c to 215°c

Tin-Zinc 199°c

Tin-Lead 183°c

Tin-Bismuth 138°c

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Hi Opal Fruit,

 

Just want to add an extra spin on this debate/discussion, When I installed my own central heating system back in the good old UK, I used a flux that did not require cleaning the pipes first.

Does the French hard and soft solders, come with this self cleaning flux, or do I/we still need to clean the pipes, as this will be my first job in the new house.

Thanks

Jim and Lily

 

 

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[quote]Since nothing is forthcoming.... I suspect you are refering to Powerflow from Fry's. It works on light tarnish. Not corrosion or heavy "weathering".[/quote]

Opel .Try La-Co flux.Been useing it for years,use for all lead free and soft solders, brass ,tin ,mild steel, zinc, silver and lead.Remove soil or grit from the pipe and go for it.Cleans as it solders. What tradesman installs pipes that are corrosive  or heavy weathered.Happy plumbing.And polishing with your wire wool.
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We use GEB or CASTOLIN EUTECTIC flux, available here in bulk. 7 of use get through around 1kg per week. They are both also water-soluble.

Fry's and others aren't available readily in France. Merchants tend to stock large quantities of small ranges. Interestingly, La-Co jointing compound is sold here, and is, like most American products, extremely effective.

Scrupulous cleanliness = Happy bunnies

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