Silverflow brazing rod

[steamboatmodel]

Can I use Silverflow brazing rod
Chemical Composition: 0% Silver, 7.1% Phosphorus, Balance Copper
Specifications: AWS A5.8, BCuP-2, QQB-650B
Liquidus Temperature: 1500°F (816°C)
Solidus Temperature: 1350°F (732°C)
For making copper Boilers?
Regards,
Gerald.

 

[John Rudd]

I'd say yes its ok..
It is unlikely that the burner for you boiler will have suffient heat output to take the boiler's temperature to anywhere near the mp of the ss when compared with the blow torch you will need to assemble the boiler

 

[mklotz]

How can it be "Silverflow" if it contains 0% silver?

 

[Bluechip]

And while we're on the subject .. what about Goldfish ???

Tried to sell mine but apparently fell well short of $1020 / oz.

 

[Loose nut]

Cadmium free silver solder isn't it, been away for awhile but I'm back.

 

[tel]

Nah, silver free silver solder. Actually known as phoscop here and not allowed under the AMBSC codes. OK for doing your plumbing tho'.

 

[GWRdriver]

I'd say yes its ok.

It is not OK. Not allowed in England. Not allowed in OZ. Strongly discouraged in the US for maybe 30 years. It has knownd weaknesses when exposed to sulphurous atmospheres (ie, coal smoke.) It has known stress cracking problems at elevated temperatures.

 

[Noitoen]

I think they mean that it flows like silver. I use it to solder the copper wire connections in the electric motor rewinding. I solders well without stripping the enamel from the wires.

 

[d.bick]

I seem to recall the use of phosphorus brazing rod for model boilers being discouraged especially in a firebox. I would recommend a silver content of around 42% and if you want a free flowing solder and can buy a solder with 25% Cadmium in it (do follow the health and safety guidelines) That said if you have some phosphorus copper rod use it for fittings and fabricating parts. You will find the melting point of this material a fair bit higher.
Dave Bick

 

[steamboatmodel]

Nah, silver free silver solder. Actually known as phoscop here and not allowed under the AMBSC codes. OK for doing your plumbing tho'.

Do you know why its not allowed?
Regards,
Gerald.

 

[John Rudd]

It is not OK. Not allowed in England. Not allowed in OZ. Strongly discouraged in the US for maybe 30 years. It has knownd weaknesses when exposed to sulphurous atmospheres (ie, coal smoke.) It has known stress cracking problems at elevated temperatures.

Hmm...point conceeded...The op didnt post what fuel type...

 

[GWRdriver]

The op didnt post what fuel type...

John,
He may or may not use coal, and even so he might very well use phos-copper and never have a problem, but myself and others would like to see new generations of model boiler builders be at least warned of known problems. In the US we can only strongly suggest, but we do want to see them pointed in the right direction and that's about all we can do. When it comes to cost savings people are going to do what they want to do.

Gerald,
In my earlier post I mentioned the principle problems are joint deterioration in sulphurous atmospheres and joint embrittlement and cracking at elevated temperatures which IIRC are acknowledged by the US mfgs specs. Back in the 1960s a lot of US live steamers began to use it as a less expensive substitute for silver solder with the added benefit that it didn't require flux for copper to copper joints. This bumped merrily along for a while, I built my first boiler with it, but eventually, like stainless steel, problems began to emerge and it was determined to be inappropriate for boilers, and the British and Australian regs have responded. Since we have no model boiler code in the US, folks are free to use what they want but in spite of that there is very definitely a widely accepted "best practice" and phos-copper isn't it.

To put another perspective on it, even in the UK and OZ anyone is free to use phos-copper on their boiler, if'n they want, however it can never receive a certificate of fitness and compliance to the regulations. No club certification, no insurance, and with no insurance there will be no steaming up in public or club function and selling off will be very difficult. Our esteemed moderator Messr. TEL will set me staright if I've got the OZ part wrong.
Harry

 

[Loose nut]

Nah, silver free silver solder. Actually known as phoscop here and not allowed under the AMBSC codes. OK for doing your plumbing tho'.

We have something similar here called sil-phos, Silver solder with phosphorous in it to make it a self fluxing silver solder. No good for boilers when exposed to sulfurous atmospheres, tends to crack.

 

[John Rudd]

I was thinking along the lines of this product.......

http://www.billshorthousemetals.co.uk/10283/info.php?p=8&pno=0

or even this one...http://www.chronos.ltd.uk/SilverFLO.pdf

 

[steamboatmodel]

So it should be OK for non Boiler Parts, but not for boilers.
Regards,
Gerald.